Aristotle, Topics

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Aristotle, Topics. Book I, Chapter 1

1. The design of this treatise, is to discover a method by which we may be able to syllogize about every proposed problem from probable arguments; and so that we ourselves sustaining the controversy, may assert nothing repugnant. In the first place, therefore, let us show what a syllogism is, and what are the differences of it, in order that a dialectic syllogism may be assumed; for we investigate this according to the proposed discussion.

2. A syllogism, therefore, is a discourse, in which certain things being posited, something different from the things posited, happens from necessity through the things posited.

3. But demonstration is when a syllogism consists from things true and primary, or from things of such a kind as assume the principle of the knowledge concerning them, through certain things which are primary and true. And a dialectic syllogism, is that which syllogizes from probabilities.

4. Those things, however, are true and primary, which obtain belief, not through other things, but through themselves. For it is not requisite in scientific principles, to investigate the why, but each of the principles ought to be credible, itself through itself. But probabilities are those things which appear to all, or to most men, or to wise men; and to these, either to all, or to the greater part, or to those who are especially known and renowned. Moreover, a contentious syllogism is that which is constructed from things which appear to be probable, but which are not so; and which appears to consist from probabilities, or from things which appear to be probable. For not everything which appears to be probable, is probable; since none of those things which are said to be probable, has entirely a superficial image of probability, as happens to be the case with respect to the principles of contentious arguments. For immediately, and for the most part, the nature of the false in them is evident even to those who can only perceive what is small. Let, therefore, the former of those syllogisms which are called contentious, be also denominated a syllogism; but let the other, be called indeed a contentious syllogism, but not a syllogism simply; for though it appears to syllogize, yet it does not. Farther still, besides all the above-mentioned syllogisms, there are paralogisms, which consist from things appropriate about certain sciences, as happens to be the case in geometry, and the sciences allied to it. For this mode seems to differ from the above-mentioned syllogisms; since he who uses false descriptions, neither syllogizes from things true and primary, nor from probabilities; because it does not fall into definition. For he neither assumes things which appear to all men, nor those which appear to most, nor such as appear to wise men; and to these, neither to all, nor to the greater part, nor to the most renowned; but he forms a syllogism from assumptions indeed appropriate to science, yet not from true assumptions. For either by describing semicircles, not as they ought to be described, or by drawing certain lines, not as they ought to be drawn, he produces a paralogism.

5. Let, therefore, the species of syllogisms according to a rude delineation, be those which I have mentioned. And universally, let it be considered, that we have thus far defined about all that has been said, or will afterwards be said by us; because we have not undertaken to deliver an accurate discussion of any one of these particulars, but wish merely to give a rude delineation of them, thinking it to be perfectly sufficient according to the proposed method, to be able to know each of these, in some way or other.

Aristotle, Topics. Book I, Chapter 02

To what has been said, it will be consequent to show in what the ability of this treatise consists, and how far its utility is extended. It is useful, therefore, to three things, to exercise, to common conversation, and to philosophic sciences. That it is useful indeed to exercise, is from these things evident; for possessing this method, we may be easily able to argue on every proposed subject. But it is useful to common conversation; because, when the opinions of the multitude are enumerated, we may converse with them not from foreign, but appropriate dogmas, confuting whatever does not appear to us to have been well said. And it is useful to philosophic sciences, because when we are able to doubt on both sides of a question, we can easily in everything perceive the true and the false. Again, it is also useful to the first principles of every science. For it is impossible to say anything about these, from the appropriate principles of a proposed science, because they are the first principles of all sciences. But it is necessary to discuss these through probabilities in particulars. This, however, is the peculiarity of, or is especially appropriate to dialectic. For as it is of an exploring nature, it is a path to the principles of all methods.

Aristotle, Topics. Book I, Chapter 03

But we shall perfectly possess this method, when we are similarly disposed, as we are in rhetoric, medicine, and powers of this kind. And this consists in effecting from possibilities the objects of our previous choice for neither will the restoration persuade from every mode, nor the physician heal. But if nothing is omitted of possibilities, we say that he sufficiently possesses science.

Aristotle, Topics. Book I, Chapter 04

In the first place, therefore, let us survey from what particulars this method consists. If then we assume for how many, what kind of, and from what things, reasons are constructed, and how we may abound with these, we shall sufficiently obtain the thing proposed. But those things are equal and the same in number, from which arguments consist, and with which syllogisms are conversant. For arguments are produced from propositions; but those things with which syllogisms are conversant are problems. But every proposition, and every problem, manifests either genius, or peculiarity, or accident. For difference when it is general is to be arranged together with ginus. Since, however, with respect to peculiarity, one signifies the very nature of a thing, but another does not signify it; let peculiarity be divided into the two above-mentioned parts, and let that which signifies the very nature of a thing, be called definition; but let the other according to an appellation attributed in common about these, be called peculiarity. It is evident, therefore, from what has been said, that according to the present division it happens that all are four; that is, either peculiarity, or definition, or genus, or accident. No one, however, should think that we say, that each of these asserted per se, is a proposition or problem, but that from these propositions and problems are produced. But a problem and a proposition differ in mode. For when it is thus said, is a pedestrian as biped animal the definition of man? And, is animal the genus of man? A proposition is produced. But if it should be said, whether is a pedestrian as biped animal, the definition of man, or not? And, whether is animal the genus of man, or not? A problem is produced. And in a similar manner in other things. Justly, therefore, our problems and propositions equal in number. For you will make a problem from every proposition, if you change the mode.

Aristotle, Topics. Book I, Chapter 05

We must show, however, what definition, genus, peculiarity, and accident are. But definition, indeed, is a sentence signifying what a thing is. And either a sentence is employed instead of a noun, or a sentence instead of a sentence. For some things also which are signified by a sentence may be defined. With respect, however, to such as employ a noun, it is evident that they do not employ the definition of the thing, because every definition is a certain science. Nevertheless a thing of this kind must be referred to definition; as, that the becoming is beautiful. In a similar manner this also, weather sense and science are the same, or different. For concerning definitions, there is an abundant discussion, whether they are the same, or different. And in short, all things may be called definitive, which are under the same method with definitions. But that all that have been now mentioned are of this kind, is from these things evident. For when we are able to show by discussion that a thing is the same, and that it is different, after the same manner we abound with arguments pertaining to definitions. For showing that it is not the same we shall subvert the definition. What, however, is now said, is not converted. For it is not sufficient to the construction of definition to show that it is the same thing. But to the subversion of definition, it is sufficient to show that it is not the same thing. And peculiarity is that which does not manifest the very nature of a thing, but is present with a thing alone, and reciprocates with it. Thus the peculiarity of man, is to be susceptible of grammar. For if he is man he is susceptible of grammar; and if he is susceptible of grammar he is man. For no one calls peculiarity, that which is capable of being present with something else; as to sleep is present with man; not even if it should happen at a certain time to be present with man alone. If, therefore, someone should call a thing of this kind peculiarity, it will not be called peculiarity simply, but on a time, or with reference to something. For to be from the right hand, is sometimes peculiar. But biped is denominated peculiar with reference to something. Thus biped is peculiar to man, with reference to horse and dog. But that no one of those things which may also be present with something else, is reciprocally predicated, is evident; for it is not necessary if anything sleeps that it should be a man. Genus, however, is that which is predicated of many things differing in species, in answer to the question what a thing is. But those things are said to be predicated in answer to the question what a thing is, which aptly answer when it is asked what the proposed thing is. Thus it is adapted to man, when it is asked what the proposed thing is, to say, that he is an animal. This also is general, whether one thing is in the same genus with another, or in a different genus. For a thing of this kind falls under the same method with genus. For having discussed that animal is the genus of man, and in like manner of ox, we shall in the discussion assert that these are not in the same genus. Accident, however, is that which is no one of these, that is, it is neither definition, nor peculiarity, nor genus; but it is present with a thing. It is also that which may be present, and may not be present with one and the same thing period thus, to sit may be present, and may not be present with one and the same thing; and in a similar manner whiteness. For nothing hinders, but that the same thing may at one time be white, and at another time not white. Of these definitions, however, of accident, the second is the better. For the first definition being adduced, it is necessary in order to understand it, previously to know what definition, genus, and peculiarity are. But the second is self-perfect for the purpose of knowing per se, what that is which is asserted. Two accidents also, the comparisons of things with each other, in whatever manner they are derived from accident, are added; as for instance, whether the beautiful in conduct, or the advantageous, is the more eligible; and whether a life according to virtue, or according to enjoyment, is the more pleasant, and if there is any other assertion similar to these. For in everything of this kind, the enquiry is to which of the two what is predicated rather pertains. But from these things it is evident, that nothing prevents accident from sometimes and with reference to something, becoming peculiarity. Thus to sit, since it is an accident, when someone alone sits, will then be the peculiarity of him. But sitting alone, it will be a peculiarity with reference to those who do not sit. Hence, nothing hinders accident from becoming peculiarity with reference to something, and sometimes. Simply, however, it will not be peculiarity.

Aristotle, Topics. Book I, Chapter 06

We should not, however, be ignorant, that everything which is referred to peculiarity, to genus, and to accident, may also be adapted to definitions. For by showing that a thing is not present alone with that which is under definition, as is the case in peculiarity; or that what is assigned in the definition, is not genus; or that some one of those things which are not contained in the definition is not present, as may also be said in accident; we shall subvert definition. Hence from the reason before adduced, all those things which have been enumerated will be definitive one universal method, however, is not on this account to be investigated in all things. For neither is it easy to discover this; and if it were discovered, it would be perfectly obscure and useless to the proposed treatise. But if a peculiar method is delivered according to each of the definite genera, the discussion of the thing proposed will be easy from those things which are appropriate about each. Hence a division must be made universally, and, as was before observed, by a rude delineation; but of the rest, those which are especially appropriate to each must be adjoined, and should be denominated definitives, or generals. The particulars, however, which have now been mentioned, have nearly been added to each.

Aristotle, Topics. Book I, Chapter 07

First of all, however, it must be defined about same, in how many ways it is predicated. But same may appear (according to a rude delineation) to receive a threefold division. For we are accustomed to denominate a thing the same, either in number, or in species, or in genus. In number, indeed, when the names are many, but the thing is one; as a garment and a vestment. In species, when the things are many, but are without difference according to species; as a man is the same with a man, and a horse with a horse. For such things are said to be the same in species as are under the same species. And in like manner, those things are the same in genus which are under the same genus, as horse is the same in genus with man. It may seem, however, that water which flows from the same fountain, when it is said to be the same, has a certain difference besides the above-mentioned modes. Nevertheless it must have the same arrangement with things which in some way or other, are said to be under the same species. For all such things appear to be of a kindred nature, and to be similar with each other. For all water is said to be the same in species with all water, because they possess a certain similitude. But water from the same fountain differs in nothing else from other waters which are said to be the same, except that the similitude is more vehement. Hence we do not separate water from the same fountain from those things which in some way or other are said to be according to one species. But confessedly, that which is one in number, appears to be denominated same by all men. It is usual, however, to attribute this in many ways; and most properly and primarily, when things are said to be the same in name, or definition; as a garment and a vestment, a pedestrious biped animal, and man. But this is attributed in the second place, when things are said to be the same in peculiarity; as that which is susceptible of science, and man; and that which naturally tends upward, and fire. In the third place, when things are said to be the same from accidents; as that which sits, or is musical, and Socrates. For all these endeavor to signify one thing in number. But that what is now said, is true, may be especially learnt from those who change appellations. For frequently when we order a certain person who is sitting, to be called by his name, we change the appellation, when he to whom we give the order does not understand who it is that is signified by that name; as if he would more easily understand from accident. And in this case, we order the person who is sitting or discoursing, to be called to us; evidently considering it as the same thing to signify according to name, and to signify according to accident. Let, therefore, same, as we have said, be triply divided.

Aristotle, Topics. Book I, Chapter 08

That disputations, however, are composed from the things which have been before-mentioned, and through these, and also that they pertain to these, may in the first place be believed through induction. For if anyone considers each of the propositions and problems, they will appear to have been assumed either from definition, or from peculiarity, or from genus, or from accident. In the second place, a belief in this may be obtained through syllogism. For it is necessary that everything which is predicated of a certain thing, should either reciprocate or not with that thing. And if, indeed, it reciprocates, it will either be definition, or peculiarity. For if it signifies the very nature of a thing, it will be definition; but if it does not signify this, it will be peculiarity. For that was peculiarity, which reciprocates indeed, but does not signify the very nature of a thing. If, however, it does not reciprocate with a thing, it either belongs to those things which are predicated in the definition of a subject, or it does not. And if it belongs to those things which are predicated in definition, it will be ginus or difference; because definition consists from genus and differences. But if it does not belong to those things which are predicated in definition, it is evident that it will be accident. For accident was said to be that which is neither genus, nor peculiarity, but is present with a thing.

Aristotle, Topics. Book I, Chapter 09

After these things, therefore, it is necessary to define the genera of the Categories, in which the before-mentioned four differences are inherent. But these are in number ten, namely, what a thing is (essence), quantity, quality, relation, where, when, situation, habit, action, and passion. For always accident, genus, peculiarity, and definition, will be in one of these categories; since all propositions derived from these signify, either what a thing is, or quality, or quantity, or some one of the other categories. But from these it is evident that he who signifies what a thing is, at one time signifies essence, at another quality, at another some of the other categories. For when man being proposed, he says that the thing proposed is a man, or an animal, he says what it is, and signifies essence. But when white color being proposed, he says that the thing proposed is white or color, he both says what it is, and signifies quality. In a similar manner also, if a magnitude of one cubit being proposed, he should say that what is proposed, is a magnitude of one cubit, he will say both what it is, and signify quantity. The like must also be said in other things. For everything of this kind, whether it is itself predicated of itself, or whether genus is predicated of it, signifies what a thing is. But when it is predicated of another thing, it does not signify what a thing is, but either quantity or quality, or some one of the other categories. Hence with respect to the things with which arguments are conversant, and from which they consist, they are these, and so many. But how we must assume these, and by what means we may possess an abundance of them, we shall afterwards show.

Aristotle, Topics. Book I, Chapter 10

In the first place, therefore, it must be defined what a dialectic proposition, and what a dialectic problem are; for not every proposition, nor every problem must be considered as dialectic. For no one and dude with intellect would assume as a principle that which is not assented to by anyone; nor would he propose as a question, that which is assented to by all, or by most men. For the latter does not admit of a doubt, and the former will be granted by no one. But a dialectic proposition, indeed, is an interrogation probable either to all, or to most, or to wise men; and by these, either by all, or by most, or by the most celebrated, it is not considered as paradoxical. For any one may admit that which is assented to by wise men, unless it is contrary to the opinions of the multitude. Dialectic propositions, however, are also those which are similar to probable propositions, and which are contrary to those things which appear to be probable, proposed through contradiction; and such opinions as are according to the discovered arts. For if it is probable that there is the same science of contraries; it will also appear to be probable, that there is the same sense of contraries. And if there is one grammatical art in number, it will also be probable, that there is one art pertaining to playing on the pipe. But if there are many grammatical arts, there will also be many arts pertaining to playing on the pipe. For all these appear to be similar, and of a kindred nature. In the like manner also, those things which are contrary to probabilities, proposed according to contradiction, will appear to be probable. For if it is probable that it is necessary to benefit friends, it will also be probable that it is not proper to act ill towards them. But it is contrary, that it is necessary to act ill towards friends; and it is according to contradiction, that we ought not to act ill towards them. In a similar manner, if it is necessary to benefit friends, it is not necessary to benefit enemies. But this also is according to the contradiction of contraries. For the contrary is, that it is necessary to benefit enemies. The like must also be said in other things. The contrary, however, about the contrary will appear to be probable in comparison; as, if it is necessary to benefit friends, it will also be necessary to act ill towards enemies. But to benefit friends may appear to be contrary to acting ill towards enemies. Whether, however, it is so or not in reality will be shown in what we shall say about contraries. But it is evident, that those opinions also which are according to the arts, are dialectic propositions. For someone may admit things which are assented to by those who are conversant with these things; as, for instance, he may admit, that the decision of the physician in medical concerns, is to be assented to; and the decision of the geometrician in geometrical concerns. And in a similar manner in other things.

Aristotle, Topics. Book I, Chapter 11

But a dialectical problem is a theorem pertaining either to choice and aversion, or to truth and knowledge; and that either per se, or as cooperating to something else of this kind; about which there is either an opinion in neither part, or the multitude are of an opinion contrary to the wise, or the wise contrary to the multitude, or each of these are at variance with themselves. For with respect to some problems, the knowledge of them is useful, for the purpose of choosing, or avoiding anything; as, for instance, whether pleasure is good, or not. But others are useful with a view to knowledge alone; As, for instance, whether the world is perpetual, or not. And some are of themselves useful for neither of these purposes; yet they cooperate to something of this kind. For there are many things which we do not wish to know by themselves, but for the sake of other things, that through these we may know something else. Those also are problems of which the syllogisms are contrary (for they contain a doubt, whether they subsist in this manner or not, because about both there are probable arguments) and those about which we have no argument, on account of their magnitude, conceiving it to be difficult to assign a reason why they exist; as, for instance, whether the world is perpetual, or not. For some one may investigate things of this kind. Lead, therefore, problems and propositions be divided, as we have said. But a thesis, is a paradoxical opinion of some celebrated philosopher; as, that it is not possible to contradict, as Antisthenes said; or that all things are moved, according to Heraclitus; or that being is one, as Melissus said. For it is folly to pay attention to the assertion of any casual person, when it is contrary to the general opinion. Or a thesis is an opinion about things of which we have a reason, when they are contrary to opinions; as, that not everything which is, is either generated or perpetual, as the sophists say; for according to them, he who is a musician is a grammarian, though he is neither generated, nor is perpetual. For this, though it should not be admitted by someone, may appear to be, because it possesses a persuasive reason. A thesis, therefore, is also a problem; But not every problem is a thesis. For some problems are of that kind, that we do not form an opinion of them in either part. But that a thesis is also a problem, is evident. For from what has been said, it is necessary, either that the multitude should be at variance with the wise, about a thesis, or one or other of these among themselves a semi colon because a thesis is a certain paradoxical opinion. Now, however, nearly all dialectic problems are called theses. Let it, however, be considered as a matter of no consequence, in whatever manner it may be denominated. For it is not because we wish to fabricate names that we thus divide them; but lest we should be ignorant what are the differences of these. But it is not necessary to consider every problem, nor every thesis; but that which may be the subject of doubt to some one, who is in want of argument, and not of punishment, or sense. For those who doubt, whether it is necessary or not to worship the gods, and love our parents, are in want of punishment. But those who doubt whether snow is white or not, are in want of sense. Nor is it necessary to discuss things, of which the demonstration may be easily obtained; nor those of which the demonstration is very remote. For the former are not dubious; and the latter require a discussion greater than that which is adapted to dialectic exercise.

Aristotle, Topics. Book I, Chapter 12

These things being determined, it is necessary to explain how many species there are of dialectic arguments. And one of these, indeed, is induction; but the other is syllogism. What syllogism, therefore, is, has been before shown. But induction is a progression from particulars to universals. As, if there is a pilot well skilled in his art, he is a most excellent pilot, and this is also true of a charioteer; and, in short, he who is properly skilled in anything, is most excellent in that thing. Induction, however, is an instrument more adapted to persuade, is clearer, and according to sense more known, and is common to many things a semi colon but syllogism is more compulsive, and is more efficacious against those who are skilled in disputing.

Aristotle, Topics. Book I, Chapter 13

Let, therefore, the genera about which, and from which arguments are produced, be defined in the manner before-mentioned. But the instruments through which we abound with syllogisms and inductions are four; one of which is, to assume propositions; the second is, to be able to distinguish in how many ways anything is predicated; the third, is to discover differences; and the fourth, is the consideration of the similar. After a manner, however, there are three propositions of these. For it is possible according to each of them to produce a proposition; as, that the beautiful, or the pleasant, or the profitable, is eligible. Also, that sense differs from science; because he who loses the latter may again acquire it; but it is impossible to regain the former when lost. And that the salubrious has the same relation to health, as that which produces a good habit of body has to a good habit of body. But the first proposition is derived from things which are predicated in many ways; the second is derived from differences; and the third from similars.

Aristotle, Topics. Book I, Chapter 14

Propositions, therefore, are to be selected in as many ways, as there are modes in the definition of a proposition; so that we may select, either the opinions of all men, or of most, or of wise men; and of these, either of all, or of most, or of the most celebrated; or that we may select opinions contrary to the phenomena; and such as are according to art. It is necessary, however, to propose according to contradiction, those opinions which are contrary to the phenomena, as was before observed. But it is useful to produce them, by selecting not only those which are probable, but also those which are similar to these; as, that there is the same sense of contraries, for there is the same science; and that we see, in consequence of receiving something, and not by emitting anything; since this is also the case in the other senses. For we hear by receiving, and not by emitting something; and after the same manner, we taste and smell. This is also the case with the other senses. Again, such particulars as are seen in all, or in most things are to be assumed as principles and probable theses. For these are posited by those who do not see that this does not take place in a certain thing. It is also requisite to select from written arguments. But descriptions are to be made about each genus separately supposed; as, about good, or about animal; and about every good, beginning from the question what it is. The opinions, likewise, of the several wise men are to be noted, as, that Empedocles says that there are four elements of bodies. For anyone will admit as a position, that which was asserted by some celebrated philosopher. But (to speak according to a rude delineation) there are three parts of propositions and problems. For some propositions are ethical, others are physical, and others logical. The ethical, therefore, are of such a kind as, whether it is necessary rather to be obedient to parents than to the laws, if they are discordant with each other. But the logical are such as, whether there is the same science or not of contraries. And the physical are such as, whether the world is perpetual or not. The like also takes place in problems. It is not, however, easy to explain by definition what the quality is of each of the above-mentioned propositions; but we must endeavor to show each of them by the custom arising from induction, directing our attention to the before-mentioned examples. So far, therefore, as pertains to philosophy, we must treat of these according to truth; but so far as pertains to opinion, dialectically. All the propositions, however, are to be assumed as much as possible universal; and one should produce many; as, that there is the same science of opposites, and afterwards, that there is the same science of contraries, and also of relatives. After the same manner, these likewise are to be divided, as long as it is possible to divide them; as that there is the same science of good and evil, of black and white, of the cold and the hot. A similar mode of proceeding must also be adopted in other things. Concerning propositions, therefore, what has been said is sufficient.

Aristotle, Topics. Book I, Chapter 15

But in how many ways a thing may be predicated must be so discussed, that we must not only endeavor to explain such things as are predicated in a different manner, but also the reasons of them. Thus, for instance, it should not only be explained, that in one way, justice and fortitude are said to be good, and that which contributes to a good habit of body, and to health, in another way; but also that some things are called good because they are certain qualities; and others, because they are effective of something, and not because they are certain qualities. And in a similar manner in other things. But whether anything is predicated multifariously in species, or in one way only, must through these things be surveyed. In the first place, indeed, it is necessary to consider in the contrary, if it is multifariously predicated, whether it is discordant in species, or in name. Or some things immediately differ in names; as, invoice the grave is contrary to the acute; but in magnitude the obtuse. It is evident, therefore, that the contrary to the acute is multifarious sly predicated. But if this be the case, the acute also will be multifariously predicated. For according to each of these, the contrary will be different; since the same acute will not be contrary to the obtuse end the grave; but the acute will be contrary to each. Again to the grave, in voice, indeed, the contrary is the sharp; but in bulk, the light. Hence the grave is multifariously predicated, since the contrary to it also is. In a similar manner to the beautiful, in an animal, the contrary is the deformed; but in a family, the depraved; so that the beautiful is homonymous. In some contraries, however, there is no dissonance in names, but the difference in them is immediately evident in species; as, in the white and the black. For voice is said to be black and white; and in a similar manner color. In these, therefore, there is no dissonance in names; but the difference in them, is immediately manifest in species. For color and voice are not similarly said to be white. But this is also evident from sense. For of those things which are the same in species, there is the same sense. We do not however, judge of the white which is in voice, and of that which is in color, by the same sense; but the one by sight, and the other by the hearing. In a similar manner, the acute and the obtuse, in sapors and in magnitudes, are not judged by the same sense; but the one by the touch, and the other by the taste. For neither do these differ in names; because neither is this difference in them; nor in the contraries. For that is obtuse which is contrary to each of these. Again, it must be considered, whether a certain thing is contrary to one of these, but nothing, in short, to the other; as, the pleasure which arises from drinking, is contrary to the pain which arises from thirst; but nothing is contrary to the pleasure arising from contemplating that the diameter of a square is incommensurable with its side. Hence pleasure is multifariously predicated. To hate also, is contrary to the love which is mental; but nothing is contrary to the love which subsists according to corporeal energy. It is evident, therefore, that to love is homonymous. Again, the media also, are to be considered; namely, whether there is a certain medium of some things, but not of others; or whether there is, indeed, a medium of both, but not the same; as, of white and black, in color, indeed, the medium is the dark brown; but in voice nothing is the medium; unless the hoarse; as some say, that a hoarse voice is the medium. Hence, the white is homonymous; and in a similar manner the black. Farther still, it must be considered, whether of some things there are many media; but of others one; as in white and black. For in colors there are many media; but in voice there is one, namely, the hoarse. Again, in that which is opposed according to contradiction it must be considered, whether it is predicated multifariously. For if this is predicated multifariously, that also which is opposed to this will be predicated multifariously. Thus, not to behold, is predicated multifariously; in one way, indeed, not to possess sight; in another, not to energize with the site. But if this is multifariously predicated; it is necessary that to behold should be multifariously predicated. For to each signification of the verb not to behold something is opposed. Thus to possess sight, is opposed to the not possessing it; and to energizing with the site, to the not energizing with it. Again, in those things which are predicated according to privation and habit, this must be considered. For if one of these is predicated multifariously, the other is also. Thus, if to perceive is predicated in many ways, that is, according to the soul, and according to the body, that which is deprived of sense will also be multifariously predicated, that is, both according to the soul, and according to the body. It is manifest, however, that the particulars which have now been mentioned, are opposed according to privation and habit; since animals are naturally adapted to have each of the senses, that is, both according to the soul, and according to the body. Again, this must also be considered in the cases of a noun. For if justly is predicated multifariously; the just also will be predicated multifariously. For the just subsists according to each of just actions. Thus, if when a man judges according to his own opinion, and in such a manner as is proper, he is said to judge justly; the just also will be similarly predicated. In like manner also, if the salubrious is predicated in many ways, the salubriously will be multifariously predicated. Thus, if that is said to be salubrious which produces, preserves, and signifies health; the salubriously also will be predicated, either productively, or preservingly, or significantly. And in a similar manner in other things, when the noun is multifariously predicated, the case derived from it will also be predicated in many ways; and if the case, likewise the noun itself. But it is also necessary to consider the genera of the categories according to name, whether they are the same in all things. For if they are not the same, it is evident that what is predicated is homonymous. Thus, the good in food, is that which is productive of pleasure; In medicine, that which is productive of health; and in the soul, to be endued with a certain quality, such as to be temperate, or brave, or just. In a similar manner also, in man. Sometimes, however, it consists in the when; as the good which subsists in opportunity. For that is said to be good which is in season. But frequently quantity is said to be good, as, for instance, the moderate; for the moderate also is said to be good. Hence the good is homonymous. In a similar manner the white, in body, indeed, is color; but in voice that which may easily be heard. Thus, too, with respect to the acute; for it is not predicated after the same manner in all things. For a rapid is said to be an acute voice, as the musicians say who are conversant with numbers; But an angle is acute which is less than a right angle; and a sword is acute which has a sharp point. It is likewise requisite to consider the genera of those things which are under the same name, whether they are different, and not subaltern. The onos is both an animal and a vessel; since the definition of them according to the name is different. For the one is said to be a certain kind of animal; But the other, a certain kind of vessel. But if the genera are subaltern, it is not necessary that the definitions should be different; as of a crow, both animal and bird are the genus. When, therefore, we say that a crow is a bird, we also say that it is a certain kind of animal; so that both genera are predicated of it. In like manner also, when we say that a crow is a winged biped animal, we say that it is a bird; and thus both genera are predicated of the crow, and also the definition of them. This, however, does not happen in genera which are not subaltern. For neither when we speak of a vessel, do we speak of an animal; nor when we speak of an animal, do we speak of a vessel. But it is necessary to consider not only whether the genera of a thing proposed are different and not subaltern, but also in the contrary. For if the contrary is multifariously predicated, it is evident that the thing proposed is also predicated in many ways. It is likewise useful to look to the definition produced from the composite; as of a white body, and a white voice. For the peculiarity being taken away, it is necessary that the same definition should remain. But this does not happen in things homonymous; as, for instance, in those things which have now been mentioned. For that if it is defined will be a body having such a color; but this will be a voice which may be easily heard. Body and voice, therefore, being taken away, that which remains is not the same in each definition. It would be necessary, however, if the word white was synonymous, that what is predicated in each definition should be the same. Frequently, too, in definitions themselves, the homonymous which is consequent is concealed. Hence also definitions are to be considered. Thus if any one should say, that what is significant, and what is productive of health, are to possess symmetry with respect to health, we must not desist, but consider what is called symmetry in each; as if the one should be so-called, because it is a thing of such a kind as to produce health; but the other because it signifies the quality of the habit. Again, it must be considered, whether they can be compared according to the more, or from similitude; as, for instance, a white voice, and a white garment; and an acute sapor, and an acute voice. For these are neither similarly said to be white or acute, nor the one more than the other. Hence the acute and the white are homonymous. For everything which may be compared is synonymous; since it either may be similarly predicated, or the one more than the other. Since, however, of things heterogeneous, and which are not arranged under each other, the differences also are different in species; (as of animal and science; for the differences of these are different) it is requisite to consider whether those things which are contained under the same name are the differences of different, and not of subaltern genera; as the acute is the difference of voice and magnitude. For voice differs from voice in acuteness; and in a similar manner one mass from another. Hence the acute is homonymous; for these are the differences of different and not of subaltern genera. Again, it must be considered, whether of things contained under the same name the differences are various; as of the chroma which is in bodies, and of that which is in melodies. For the differences of that which is embodies are, that which separates and that which congregates the sight; but there are not the same differences of that which is in melodies. Hence chroma is an homonymous word; for of the same things there are the same differences. Farther still, since species is not the difference of anything; (for man and ox are not difference, but each of them is a species) — it is necessary to consider whether of those things which are contained under the same name, the one is species, but the other difference. Thus the whiteness which is in body is a species of color, but that which is in the voice is a difference of color; for voice differs from voice in being white (that is, in being clear). Such things, therefore, as are multifariously predicated, must be considered through these and things of this kind.

Aristotle, Topics. Book I, Chapter 16

The differences also in genera themselves with respect to each other, must be surveyed; as, for instance, what difference there is between justice and fortitude, and between prudence and temperance; for all these are from the same genus, virtue. This must also be surveyed in different genera, which do not very much differ from each other; as, what the difference is between sense and science. For in things which are very different from each other, the differences are perfectly manifest.

Aristotle, Topics. Book I, Chapter 17

But similitude is to be considered in those things which are indifferent genera thus; as one thing is to a certain other thing, so is one thing to another. Thus, for instance, as science is to the object of science, so is sense to that which is sensible. Likewise, as one thing is in a certain other thing, so is another thing in another. Thus, as sight is in the eye, so is intellect in the soul; and as tranquility is in the sea, so is serenity in the air; for each of them is quiet. But it is especially requisite to be exercised in things which very much differ from each other. For in the rest we may easily perceive similitudes. It must also be considered with respect to things which are in the same genus, whether something which is the same is present with all of them; as, for instance, in man, and horse, and dog. For so far as something which is the same as present with them, so far they are similar.

Aristotle, Topics. Book I, Chapter 18

It is also useful for the purpose of perspicuity, to consider in how many ways a thing may be predicated. For anyone will more easily understand what he admits, when it is explained in how many ways a thing is predicated. It likewise contributes to the constructions of syllogisms against a thing itself, and not against the name of it. For when it is in manifest in how many ways a thing is predicated; it is possible that he who answers and he who interrogates question may not direct their attention to the same thing period but when it is explained, in how many ways it is predicated, and to what he directs his attention by whom it was introduced; he who interrogates will appear ridiculous, unless he frames his arguments from this. It is also useful for the purpose of not being deceived by paralogism ourselves, and of deceiving another by paralogism. For when we know in how many ways a thing may be predicated, we shall not be deceived by paralogism, but we shall know if he who interrogates does not argue against the same thing; but we ourselves when interrogated, shall be able to deceive by paralogism, unless he who answers happens to know in how many ways the thing may be predicated. This, however, cannot always be affected in all things; but when of things which are multifariously predicated, some are true, and others false. But this mode is not appropriate to dialectic. Hence a thing of this kind ought to be perfectly avoided by those who are skilled in dialectic, namely, arguing against a name, unless someone should be otherwise incapable of discussing the thing proposed. To discover, however, differences, is useful to the construction of syllogisms concerning the same and a different thing, and also to the knowledge of what anything is. That it is useful, therefore, to the construction of syllogisms about the same and different, is evident. For when we have discovered the difference of the things proposed, of whatever kind it may be, we shall be able to show that they are not the same. And it is useful to the knowledge of what a thing is, because we are accustomed to separate the proper definition of the essence of each thing, by the proper differences of each. But the contemplation of the similar is useful to inductive reasons, to syllogisms from hypothesis, and to the explanation of definitions. It is useful to inductive reasons, because by the induction of similar particulars, we think fit to conclude the universal. For it is not easy to form induction without a knowledge of similars. But it is useful to syllogisms from hypothesis, because it is probable, that as a thing subsists in one of those things which are similar, so likewise it will subsist in the rest. Hence in order that we may be able to discuss any one of them copiously, we should previously acknowledge, that such as is the condition of a thing in these, such also is its condition in that which is proposed. But having demonstrated that, we shall also have demonstrated the thing proposed from hypothesis. For having supposed, that such as is the condition of a thing in those, such also is its condition in that which is proposed, we shall form a demonstration. And it is useful to the explanation of definitions, because if we are able to perceive what in each thing is the same, we shall not be dubious to what genus the thing proposed to be defined, ought to be referred. For of things which are common, that which is especially predicated in the question what a thing is, will be the genus. In a similar manner also, in things which very much differ from each other, the contemplation of the similar is useful to definitions; as that tranquility in the sea, is the same thing as serenity in the air; for each of them is quiet. And that a point in a line is the same thing as unity in numbers; for each of them is a principle. Hence by assigning the common genus in all things, we shall appear not to define in a foreign manner. Nearly, however, those who define, are accustomed thus to explain. For they say that unity is the principle of number; and that a point is the principle of a line. It is evident, therefore, that the genus of each, is referred to that which is common. Hence, the instruments through which syllogisms are constructed are these. But the places to which what we have said contributes are those which will be explained in the following books.

Aristotle, Topics. Book II, Chapter 1

Book II, Chapter 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11

Of problems some are universal, but others partial. The universal, therefore, are such as that “All pleasure is good.”, and “No pleasure is good.”. But the partial are such as, “A certain pleasure is good.”, and “A certain pleasure is not good.”. The things, however, which are common to both genera of problems are such as universally effect and subvert. For having shown that a thing is present with every individual, we shall also be able to show that it is present with a certain individual. In a similar manner also, if we should show that it is present with no individual, we shall also be able to show that it is not present with every individual. In the first place, therefore, we must speak concerning those things which are universally subversive, as well because such things are common to universal and partial problems, as because these are rather introduced by asserting that a thing is present or inherent, than by asserting that it is not; but this is subverted by those who engage in discussions. It is most difficult, however, to convert an appropriate appellation which is derived from accident; for it to be inherent partly, and not universally, is possible in accidents alone. For it is necessary that the appellation which is derived from peculiarity, definition, and genus, should be converted. Thus, if to be a pedestrious biped animal is present with a certain thing; a conversion being made it will be true to say that it is a pedestrious biped animal. And in a similar manner in the appellation which is derived from genus; for if to be an animal is present with a certain thing, that thing is an animal. The like also takes place in peculiarity. For if to be receptive of grammar is present with a certain thing, it will be receptive of grammar; since no one of these can be partly present, or not present; but each must be simply present or not present. Nothing, however, hinders but that accidents may be partly present or inherent; as, for instance, whiteness or justice. Hence it is not sufficient to show that whiteness or justice is inherent, in order to show that a man is white or just. For it is dubious, because he may be partially white or just. On this account, conversion is not necessary in accidents. It is also necessary that the errors which arise in problems should be determined, which are two, and arise either from asserting a falsehood, or a departing from the established mode of speaking. For those who assert what is false, error by saying that what is not present, is present with a certain thing. And those who call things by foreign names, as those who call a plain tree a man, depart from the established mode of appellation.

Aristotle, Topics. Book II, Chapter 2

One place, therefore, is to consider whether that which is inherent according to some other mode, is to be assumed as an accident. But this error especially takes place about genera. As, if someone should say, that it happens to whiteness to be a color; for color is not an accident to whiteness, but is the genus of whiteness. It is possible, therefore, that he who adopts a thesis, may according to nomination define it to be an accident, as, that it happens to justice to be a virtue. Frequently, however, without definition it is evident, that genus is assumed as accident. As, if anyone should say that whiteness is colored, or that walking is moved. For the predication of species is asserted paronymously from no genus, but all genera are predicated of species synonymously. For species receive the name and the definition of genera. He, therefore, who says that whiteness is colored, neither assumes as genus, since he says this paronymously; nor as peculiarity, nor as definition; for definition and peculiarity are present with nothing else; but many other things are colored; such as wood, stone, man, horse. It is evident, therefore, that it is assumed as accident. Another place is, to look to those things, with all or with none of which a thing is said to be present; and to consider according to species, and not in infinite individuals; for thus the survey will proceed in a more certain path, and in fewer things. But it is necessary to consider, and to begin from first things, and afterwards proceed as far as to individuals. Thus, if it should be said that there is the same science of opposites; it must be considered whether there is the same science of relatives, of contraries, and of those things which are said to be opposites according to privation and habit, and also of those which are according to contradiction. And if in these, it should not be yet evident, again these must be divided as far as to individuals; as, whether there is the same science of things just and unjust, or of the double and the half, or of blindness and sight, or of being and non-being. For if it should be shown in a certain thing, that there is not the same science, the problem will be confuted. In a similar manner also if it should not be present with anything. This place, however, converts, and is subservient to confirmation and refutation. For if divisions being introduced, it should appear to be in all, or in many things; the opponent must be requested to concede universally, or to object, and show, in what it is not so. For if he does neither of these, he who does not concede will appear to act absurdly. Another place, is to define accident and that to which it is an accident, either both of each, or one only; and afterwards to consider whether anything is assumed as true, which in the definitions is not true. Thus, if the problem is, that God may be injured, it must be considered what it is to injure. For if it is, to hurt voluntarily, it is evident that it is not possible God can be injured; for it is not possible that God can be hurt. Likewise, if it should be asserted that a worthy man is envious, it must be considered who is envious, and what envy is. For if envy is pain arising from the apparent success of some worthy person; It is evident that a worthy man is not envious; for if he were, he would be depraved. And if he who is apt should be indignant, should be said to be envious, it must be explained, who each of these is. For thus it will be evident whether what is said, is true or false. Thus, if he is envious who is pained by the success of good men; but he is apt to be indignant who is pained by the success of bad men; it is evident that he who is apt to be indignant will not be envious. It is also necessary to assume definitions, instead of the names introduced in definitions; and not to desist, till we arrive at that which is known. For frequently, when the whole definition is given, the object of investigation is not manifest; but if instead of some name placed in the definition, the definition is delivered, it becomes evident. Again, when a problem is proposed, it must be changed into a proposition, and then objected to; For the objection will be an argument against the thesis. This place, however, is nearly the same as to survey either all, or no one of those things, with which a thing is said to be present, but it differs in the mode. Farther still, it is necessary to define what kind of things it is requisite to denominate as the multitude denominate them, and what kind it is not requisite. But this is useful both to confirmation and confutation. As, that things are to be called by those names which the multitude use; but that attention is no longer to be paid to the multitude with respect to the quality of things. Thus, that is to be called salubrious which is productive of health, as the multitude call it; but whether what is proposed is productive of health or not, must be no longer determined by what the multitude assert, but by what the physician says.

Aristotle, Topics. Book II, Chapter 3

Again, if anything should be multifariously predicated, but it is posited as inherent, or as not inherent, one of those things which are multifariously predicated must be proved, if both cannot be proved. But this place is to be used in things which are latent. For if it is not concealed that a thing is predicated in many ways, he who defends the thesis may object, that the thing of which he is dubious is not the subject of dispute, but something else. But this place converts, and is useful both for confirming and subverting. For when we wish to confirm we show that the one is inherent, if we are not able to show this of both; and when we subvert, we show that the other is not inherent, if we are unable to show that both are inherent. It is not, however, necessary that he who subverts should discourse from compact, neither if a thing were said to be present with every individual, nor if it were said to be present with no individual. For if we should show that it is not present with any individual whatever, we shall subvert the problem which asserts that it is present with every individual. In a similar manner also, if we should show that it is present with one thing, we shall subvert the problem which asserts that it is present with nothing. But in confirming, it must be previously acknowledged, that if it is present with anything, it is present with everything, if the axiom is probable. For it is not sufficient in order to show that it is present with everything, to discourse about one thing; as, if the soul of man is immortal, to prove that every soul also is immortal. Hence it must be previously acknowledged, that if any soul is immortal, every soul also is immortal. This, however, is not always to be done, but when we are unable to adduce one common reason in all things; just as a geometrician proves by one common reason that a triangle has three angles equal to two right. But if it is not latent that a thing is multifariously predicated; when it is determined in how many ways it is predicated, it is requisite both to subvert and confirm. Thus, if the becoming is the advantageous, or the beautiful, we should endeavor to confirm or subvert both about the proposed problem; as for instance, that it is beautiful and advantageous, or that it is neither beautiful, nor advantageous. If, however, it is not possible to prove both, one of them must be proved, having indicated that the one is, but the other not. The reasoning is the same though the division should be into more than two members. Again, those things must be considered which are predicated multifariously, but not according to equivocation, but after another manner. Thus science is one of many things, either as belonging to the end, and to that which pertains to the end, as medicine is the science of producing health, and prescribing proper food, or as belonging to both ends, as of contraries there is said to be the same science, for the one is no more an end than the other; or as pertaining to that which is per se, and to that which is according to accident; as we know per se, that a triangle has three angles equal to two right; but according to accident that it is equilateral. For because it happens to an equilateral triangle, that it is a triangle, according to this we know that it has internal angles equal to two right. If therefore, it is by no means possible that there should be the same science of many things, it is evident that it is entirely impossible. Or if it is in a certain respect possible, it is evident that it is possible. But it is requisite to divide in how many ways the useful subsists. Thus, for instance, if we wish to confirm, such things are to be introduced as are possible; and they must be divided into those things only which are useful to the confirmation. But if we wish to subvert, such things as are not possible must be introduced; and the rest must be omitted. And this method must be adopted in these, when it is latent in how many ways they are predicated. That this thing also pertains, or does not pertain to this thing, must be confirmed from these places; as, that this science is of this thing, either as pertaining to the end, or as pertaining to things which belong to the end, or as pertaining to things which are from accident. Or, on the contrary, it must be confirmed that a certain thing is not according to any one of the before-mentioned modes. There is also the same reasoning about desire, and such other particulars as are said to pertain to many things. For desire pertains to this thing, either as to the end, as to health; or as pertaining to things which are referred to the end, as to the taking medicine; or as to that which is from accident, as in wine, he who is a lover of sweetness, desires wine, not because it is wine, but because it is sweet. For he desires sweetness per se, but the wine from accident; since if the wine should be austere, he will no longer desire it. He desires the wine, therefore, from accident. This place, however, is useful in relatives; For nearly things of this kind belong to those which are referred to a certain thing.

Aristotle, Topics. Book II, Chapter 4

The mutation also into a name more known is useful; as, for instance, the clear, instead of the accurate, in opinion; and the love of employment instead of being engaged in various occupations. For when that which is asserted becomes more known, the thesis may be more easily opposed. This place also pertains in common both to subversion and confirmation. But in order to show that contraries are present with the same thing, it is requisite to direct our attention to genus. Thus, if we wish to show there is rectitude and error about sense; because to perceive according to sense, is to judge; and it is possible to judge rightly and not rightly; about sense also there will be rectitude and error period now, therefore, from genus the demonstration is concerning species; for to judge is the genus of is sensible perception; since he who sensibly perceives judges in a certain respect. Again, from species, the being present with genus may be shown. For such things as are present with species, are also present with genus. Thus, if science is depraved and worthy, disposition also is depraved and worthy; for disposition is the genus of science. The former place, therefore, is false, if employed for the purpose of confirmation; but the latter is true. For it is not necessary that such things as are present with genus, should also be present with species. For animal is winged and four-footed, but man is not. But such things as are present with species, are necessarily also present with ginus. For if man is worthy, animal also is worthy. For the purpose, however, of subverting, the former is true, but the latter false. For such things as are not present with genus, neither are present with species; but it is not necessary that such things as are not present with species, should not be present with genus. But since it is necessary, that of those things of which genus is predicated, some species should also be predicated; and since such things as have genus, or are paronymously denominated from genus, necessarily have a certain species, or are paronymously denominated from a certain species; (as if science is predicated from a certain thing, grammar, or music, or some other science, will also be predicated of it; and if anyone possesses science, or is peroni musely denominated of science, he will also possess grammar, or music, or some one of the other sciences, or will be paronymously denominated from some one of them, as, for instance, he will be called a grammarian, or a musician) — this being the case, if anything should be posited which is denominated in any way from genus, as, that the soul is moved; it must be considered whether it is possible for the soul to be moved according to some one of the species of motion, as, to be increased, or diminished, or corrupted, or generated, or such other species of motion. For if it is not possible for it to be moved according to any species of motion, it is evident that the soul is not moved. But this place pertains in common both to confirmation and subversion. For if the soul is moved according to some one of the species of motion, it is evident that it is moved; and if it is not moved according to any species of motion, it is evident that it is not moved. He, however, who does not abound with arguments pertaining to the thesis, ought to consider from the definitions which either exist, or appear to exist, of the proposed thing; and if he cannot effect this from one, he should effect it from many. For it will be easy for those two argue who define; since an opposition to definitions is easy. It is also requisite to consider in the proposed problem to what certain saying it pertains; or what will necessarily follow, if the thing proposed exists. He, therefore, who wishes to confirm, should consider to what the thing proposed necessarily pertains. For if that is shown to exist, the thing proposed will also be demonstrated. But he who wishes to subvert, should consider what will be the consequence, if the thing proposed exists; for if we can show that what is consequent to the thing proposed does not exist, we shall subvert the thing proposed. Again, it is also necessary to direct our attention to time, if it is in a certain respect discordant; as, if someone should say, that what is nourished is necessarily increased. For animals are always nourished, but are not always increased. In a similar manner also, if someone should say, that too no scientifically is to remember. For science pertains to the past, the present, and the future time; since we are said to know scientifically things present, and future, as, that there will be an eclipse of the sun. But it is not possible to remember anything except that which is passed.

Aristotle, Topics. Book II, Chapter 5

Again, it is also a sophistical place, to bring the opponent to that against which we abound with arguments. But this will sometimes, indeed, be necessary, sometimes will appear to be necessary, and sometimes will neither appear to be, nor will be necessary. It is necessary, therefore, when he who answers denies something which is useful to the thesis, and against this the arguments are directed; but it happens that it is a thing of that kind against which it is possible to abound with arguments. The like also takes place, when someone by making an abduction to a certain thing, through that which is posited, endeavors to subvert that thing; for this being subverted, the thing proposed is also subverted. But it will appear to be necessary, when it seems, indeed, to be useful, and appropriate to the thesis, but is not so to that against which the arguments are adduced; whether he who sustains the argument denies, or whether from a probable abduction through the thesis against it, he endeavors to subvert it. And that which remains is, when that against which the arguments are directed, is neither necessary, nor appears to be so; but otherwise it happens, that he who answers argues sophistically. It is necessary, however, to avoid the last of the above-mentioned modes; for it appears to be perfectly remote and foreign from dialectic. Hence it is necessary that he who answers should not be morose, but should admit things which are not useful to the thesis, signifying whatever does not appear to him to be true, though he thinks fit to admit it. For it happens for the most part, that those who interrogate are more involved in doubt, everything of this kind being conceded to them, if they do not conclude. Farther still, everyone who says anything, after a manner says many things, because many things are consequent from necessity to each thing. Thus he who says that man is, says also that animal is, and also animated, biped, and that which is receptive of intellect and science. Hence, any one of those things which are consequent being subverted, that also which was proposed at first is subverted. It is necessary, however, to be cautious, lest the transition should be made to that which is more difficult. For some times it is easier to subvert what is consequent, and sometimes the thing proposed itself.

Aristotle, Topics. Book II, Chapter 6

In those things, however, with which it is necessary that one thing alone should be present or not present, as, with man it is necessary that disease or health should be present; if we abound with arguments about one of these, that it is present or not present, we shall also abound with arguments concerning the other. But this converts with respect to both. For having shown that one of them is present, we shall have proved that the other is not present. But if we show that one of them is not present, we shall have proved that the other is present. It is evident, therefore, that this place is useful to both. Again, it is necessary to argue, by transferring the name to the etymology, because it will be more appropriate thus to assume, than as the name is posited. Thus, it will be more appropriate to assume eupsychon (i.e. well animated) not as signifying a brave man, as it is posited; but as signifying ton eu tēn psychēn echonta, one whose soul is in a good condition; just as it will be more appropriate to assume euelpin, as ton agatha elpizonta, one who hopes for good; and in a similar manner hou an ho daimōn ēi spoudaios, one whose damon is good; just as Xenocrates says, that he is eudaimona, (i.e. happy) who has a worthy soul; for that this is to every man a daemon. Since, however, of things some are from necessity; but others have a subsistence for the most part; and others have a casual subsistence; if that which is from necessity is posited to subsist as for the most part; or that which subsists for the most part, is posited to subsist from necessity, or the contrary to that which subsists for the most part; it will always afford a place for argument. For if that which is from necessity is posited as subsisting for the most part; it is evident that it will not be said to be present with every individual, when it is. Hence he who makes this position will err. This will also be the case, if any one says that what subsists for the most part subsists from necessity; for he will assert that to be present with every individual which is not present. In a similar manner likewise, if he says that the contrary to that which subsists for the most part is from necessity; for the contrary to that which subsists as for the most part is always asserted in fewer things.  Thus, if men are for the most part depraved, good men are few. Hence, he will in a still greater degree err if he should say that men are good from necessity. In like manner also, if he should say, that what happens casually is from necessity, or for the most part. For that which happens casually, is neither from necessity, nor for the most part. If, however, some one should not define, whether he says that a thing is as for the most part; or as from necessity, but the thing should subsist as for the most part, it is possible to dispute, as if he said it subsisted from necessity. Thus, if a man should say that those who are destitute of hereditary possessions are depraved, without defining who they are; it may be possible to dispute against him, as if he had said, they were necessarily depraved. Again, it must be considered whether the same thing is posited to happen to itself, as if different from itself, because the name is different; just as Prodicus divides pleasures into joy, delight, and hilarity. For all these are names of the same thing, i.e. pleasure. If, therefore, any one should say that joy happens to hilarity, he will say that the same thing happens to itself.

Aristotle, Topics. Book II, Chapter 7

Since, however, contraries are conjoined with each other in six ways, but they produce contrariety when conjoined in four ways; it is necessary to assume contraries in such a manner as may be useful to him who subverts and constructs. That contraries, therefore, are conjoined in six ways is evident. For either each is conjoined to each of contraries, and this in a twofold respect, as to act well by friends, and ill by enemies; or, on the contrary, to act ill by friends and well by enemies. Or both are conjoined about one thing, and this in a twofold respect, as, to act well by friends, and to act ill by friends, or to act well by enemies, and to act ill by enemies. Or one thing is about both, and this in a twofold respect, as, to act well by friends, and to act well by enemies, or to act ill by friends, and to act ill by enemies. The first two conjunctions, therefore, which have been mentioned, do not produce contrariety. For to act well by friends, is not contrary to acting ill by enemies; since both are eligible, and proceed from the same manners. Nor is the acting ill by friends contrary to the acting well by enemies; for both these are to be avoided, and proceed from the same manners. That, however, which is to be avoided does not appear to be contrary to that which is to he avoided; unless the one is so denominated according to excess, but the other according to defect. For excess appears to be among the number of things which am to be avoided; and in a similar manner defect. But all the remaining four produce contrariety. For to act well by friends, is contrary to acting ill by friends; since they proceed from contrary manners; and the one is to be chosen, but the other to be avoided. In a similar manner also in other things. For according to each conjunction, the one is to be chosen, but the other is to be avoided; and the one proceeds from worthy, but the other from depraved manners. It is evident, therefore, from what has been said, that many things happen to be contrary to the same thing. For to act well by enemies, is the contrary to acting well by friends, as is also to act ill by friends. And similarly to each of other things to him who considers them after the same manner, there will appear to be two contraries. Whichever, therefore, of the contraries is useful to the thesis, is to be assumed. Again, if any thing is contrary to accident, it must be considered whether it is present with that with which accident is said to be present. For if this is present, that cannot be present; since it is impossible that contraries can at one and the same time be present with the same thing. Or it must be considered whether any thing of this kind is predicated of a certain thing, which if it is, it is necessary that contraries should be inherent in the same subject. Thus if any one should say that ideas are in us, it will happen that they will be moved, and be at rest; and also, that they are both intelligible and sensible. For ideas appear to be at rest, and to be immoveable and intelligible, to those who admit that there are ideas; but if they are in us, it is impossible that they should be immovable; for since we are moved, it is necessary that every thing which is in us should be moved together with us. It is also evident that they are sensible, if they are in us; for through the sense of sight we know the morphe which is in every thing. Farther still, if accident is posited, to which a certain thing is contrary, it must be considered whether also it is susceptible of the contrary which is the recipient of accident. For the same thing is susceptible of contraries. Thus, if it should be said that hatred is contrary to anger, hatred will be in the irascible part of the soul; for anger is there. It must be considered, therefore, whether friendship, the contrary to hatred, is in the irascible part. For if it is not, but is in the desiderative part of the soul, hatred will not be consequent to anger. There will also be a similar reasoning, if it should be said that the desiderative part of the soul is ignorant. For it will be receptive of science, if it is receptive of ignorance. It does not, however, appear to be the case, that the desiderative part of the soul is receptive of science. He, therefore, who refutes, should use, as we have said, this place; but this place is not useful to the confirmation of accident being inherent; though it is useful in order to show that it may be inherent. For when we have shown that it is not receptive of the contrary, we shall have shown that neither is accident inherent, nor can be inherent. But if we have shown that the contrary is inherent, or that it is receptive of the contrary, we shall not yet have shown, that accidentalso is inherent, but it will only be proved that it may be inherent.

Aristotle, Topics. Book II, Chapter 8

Since, however, there are four oppositions, it must be considered whether an argument can be derived from contradictions, the consecution being inverse, both in subverting and confirming. But this must be assumed from induction. Thus, if man is an animal, that which is not an animal is not a man. The like also takes place in other things. For here the conseqution is inverse. For animal is consequent to man; but that which is not an animal is not consequent to that which is not a man; but inversely that which is not a man is consequent to that which is not an animal. In all things, therefore, it is requisite to use a thing of this kind. Thus, if the beautiful is pleasant, that which is not pleasant, is not beautiful. And if this is not, neither will that be. In a similar manner also, if that which is not pleasant is not beautiful, the beautiful is pleasant. It is evident, therefore, that the consecution according to contradiction, when it is inverse, converts to both. In contraries, however, it must be considered both by him who subverts, and him who confirms, whether the contrary follows the contrary directly, or inversely. But things of this kind are to be assumed from induction so far as it is useful. The consecution, therefore, is direct; as, for instance, to fortitude and timidity. For to the former virtue is consequent; but to the latter vice. And the eligible, indeed, is consequent to the former; but the avoidable to the latter. The consecution, therefore, of these is direct; for the eligible is contrary to the avoidable. In a similar manner also in other things. But the consecution is also inverse; as health is consequent to a good habit of body, but disease is not consequent to an ill habit of body, but an ill habit of body is consequent to disease. It is evident, therefore, that the consecution in these is in an inverse order. The inverse, however, rarely happens in contraries; but in most of them the consecution is direct. Hence if the contrary is neither consequent to the contrary directly, nor inversely, it is evident that neither in what is asserted (i.e. the problem) is the one consequent to the other. But if in contraries, in, the problem also it is necessary that the one should be consequent to the other. As in contraries, however, thus also it must be considered in privations and habits; except that in privations there is not the inverse, but it is always necessary that the consecution should be direct; just as sense follows the sight, and a privation of sense, blindness. For sense is opposed to a privation of sense, as habit and privation; since one of these is habit, but the other is privation. Relatives, however, are to be used in a manner similar to habit and privation; for the consecution of these is direct. Thus if the triple is multiple, the subtriple is also submultiple. For the triple is referred to the subtriple, and the multiple, to the submultiple. Again, if science is opinion, the object of science will also be the object of opinion; and if vision is sense, the visible is also sensible. Here, however, it may be objected, that it is not necessary there should be a consecution in relatives, as we have said it is; for the sensible is an object of science, but sense is not science. The objection, however, does not appear to be true; for many deny that there is science of sensibles. Again, what has been said is no less useful for the purpose of proving the contrary; as, that the sensible is not an object of science; for neither is sense science.

Aristotle, Topics. Book II, Chapter 9

Again, both in subverting and constructing, co-ordinations and cases are to be considered. But such things are called co-ordinations, as things, and a just man, with justice; and courageous deeds, and a courageous man, with fortitude. In a similar manner things effective, and which have a preserving power, are co-ordinate with those things, which they preserve or produce. Thus things salubrious are co-ordinate with health; and things which produce a good habit of body, are coordinate with a good habit of body. The like also takes place in other things. Hence it is usual to call things of this kind co-ordinate. But cases are such as justly, courageously, salubriously, and such things as are denominated after this manner. Things also which are denominated according to cases, appear to be co-ordinate. Thus, the justly is co~ordinate with justice; and the courageously with courage. But all such things are said to be co-ordinate, as all are in the same class or co-ordination; as, justice, a just man, the just, justly. It Iis evident, therefore, that if it should be shown that any one of those things which are in the same co-ordination, is good or laudable, all the rest also will be shown to be good or laudable. Thus, if justice is among the number of things laudable, a just man, the just, and the justly, will also be among the number of things laudable. But the justly and the laudable will be denominated according to the same case; for the laudably is from the laudable, just as the justly is from justice. It is necessary, however, to consider the contrary not only in what has been said, but also in the contrary; as, that good is not necessarily pleasant; for neither is evil, necessarily painful; or if this is, that also is. And if justice is science, injustice is ignorance. Likewise, if that which is done justly, is done scientifically and skilfully; that which is done unjustly, is done ignorantly and unskilfully; or if these are not, neither will those be; as in the instance just now adduced. For that which is done unjustly, will rather seem to be done skilfully than unskilfully. This place, however, was before mentioned in the consecutions of contraries. For we do not establish any thing else at present, than that the contrary is consequent to the contrary. Farther still, both by him who subverts, and him who confirms, arguments are to be derived in generations and corruptions, and in things which have a power of producing or corrupting. For those things of which the generations are good, are also themselves goods; and if they are good, the generationslikewise are good. But if generations are among the number of things evil, the things generated are also evil. In corruptions, however, the contrary takes place. For if corruptions are among the number of things good, the things corrupted are evil. But if corruptions are among the number of things evil, the things corrupted are good. There is likewise the same reasoning in things which have a power of producing and corrupting. For those things of which the producing causes are good, are themselves good; and those things of which the corruptive causes are good, are themselves among the number of things evil.

Aristotle, Topics. Book II, Chapter 10

Again, it must be considered whether the like takes place in similars; as, whether if science is one of many things, opinion is also; and whether, if to possess sight is to see, to possess hearing also is to hear. The like must also be considered in other things, as well those which exist, as those which appear to exist. But this place is useful for both purposes. For if the thing thus subsists in some one similar, it will also thus subsist in other similars; but if not in some one, neither will it thus subsist in other similars. It must also be considered whether the like takes place in one thing, and in many things; for sometimes it is discordant. Thus, if to know scientifically is to energize dianoetically; to know many things scientifically, is also to energize about many things dianoetically. This, however, is not true; for it is possible to know many things scientifically, without energizing about them dianoetically. If, therefore, this is not true, neither is that true, which was asserted in one thing, viz. that to know scientifically is to energize dianoetically. Farther still, arguments must also be assumed from the more and the less. But of the more and the less there are four places. One is, if that which is more is consequent to that which is more. Thus, if pleasure is good, an increase of pleasure is an increase of good. And if to act unjustly is evil, to act more unjustly is also more evil. This place, however, is useful for both purposes. For if the accession of accident is consequent to the accession of the subject, as it was said to be in the problem it is evident that it happens; but if it is not consequent it does not happen. But this must be assumed by induction. Another place is, when one thing is predicated of two things; if it is not present with that with which it is more probable it is present, neither will it be present with that with which it is less probable it is present. And if it is present with that with which it is less probable it is present, it is also present with that with which it is more probable it is present. Again, when two things are predicated of one thing, if that which appears to be more present is not present, neither will that which is less. But if that which appears to be less present is present, that also which appears to be more present will be present. Farther still, when two things are predicated of two things, if that which appears to be more present with the one is not present, neither will that which appears to be less present with the other. But if that which appears to be less present is present, that also will be present which appears to be more present. Again, when two things are predicated of two, if that which appears to be more present with the one is not present, neither will that
which remains be present with that which remains. But if that which appears to be less present with the other is present, that which remains will also be present with that which remains. Again, an argument is to be derived from that which is similarly present, or appears to be present, in a threefold respect, just as it was observed in that which is more present in the three places last-mentioned. For whether one certain thing is similarly present with two things, or appears to be present; if it is not present with the one, neither will it be present with the other; but if it is present with the one, it will also be present with the other. Or whether two things are similarly present with the same thing; if the one is not present, neither will the other; but if the one is, the other also will be. After the same manner also, if they are similarly present with two things. For if the one is not present with the other, neither will that which remains be present with that which remains. But if the one is present with the other, that which remains will also be present with that which remains. In so many ways, therefore, it is possible to argue from the more, and the less, and the similar.

Aristotle, Topics. Book II, Chapter 11

Farther still, when an argument is formed from addition; if one thing being added to another, makes a thing to be good or white, when it was not before good or white; that which is added will be such a good or whiteness as it causes the whole to be. Again, if to that which is inherent, a certain thing being added, causes it to be more such than it was before; that also which was added will be a thing of the like kind. In a similar manner also in other things. This place, however, is not useful in all things, but in those only in which there happens to be an excess of the more. But this place does not convert for the purpose of subverting. For if that which is added does not produce good, it is not yet manifest whether it is itself not good. For good added to evil, does not from necessity make the whole to be good; nor does white added to black necessarily make the whole to he white; nor the sweet added to the bitter necessarily make the whole to be sweet. Again, if any thing is said to be more and less, it is likewise simply so. For that which is not white or good, is not said to be more or less good or white. For evil is not more or less good than any thing, but is said to be more or less evil. Neither does this place convert for the purpose of subverting. For many things which are not said to be more, exist simply. Thus man is not said to be more and less, yet not on this account he is not man. After the same manner it must be considered in that which subsists according to something, and at a certain time, and in a certain place. For if it is possible according to a certain thing, it is also simply possible. And in a similar manner with respect to that which is at a certain time, or in a certain place. For that which is simply impossible, is neither possible according to a certain thing, nor in a certain place, nor at a certain time. Here, however, it may be objected, that worthy men are naturally worthy according to a certain thing, as, for instance, they are liberal, or temperate; but they are not simply naturally worthy; for no one is naturally prudent. In a similar manner also, at a certain time, something which is corruptible may not be corrupted; but simply, it is not possible it should not be corrupted. After the same manner also in a certain place it is profitable to use a certain kind of diet, as, for instance, in infectious places; but simply it is not profitable. Farther still, in a certain place, it may be possible for one thing only to be, but simply it may not be possible that there should only be one thing. After the same manner, at a certain place, it is considered as a worthy action to immolate a father, as among the Tribali; but simply it is not a worthy action. May we not say, that this does not signify a certain place, but to certain persons? For it is of no consequence where they may be; since it will every where be a worthy action with them, as they are the Tribali. Again, sometimes the taking a medicine is profitable, as when a man is ill, but simply it is not profitable. Or may we not say, that neither does this signify a certain time, but has reference to him who is disposed in a certain way? For it is of no consequence when.it is done, if only he is thus disposed. But that simply is, which when nothing is added, you may say is beautiful, or the contrary. Thus, you would not say that to immolate a father is beautiful, but that it is beautiful to certain persons. It is not, therefore simply beautiful. But you will say, that to reverence the gods is beautiful, without any addition; for it is simply beautiful. Hence, that which without the addition of any thing, appears to be beautiful or base, or any thing else of this kind, must be said to be so simply.

Aristotle, Topics. Book III, Chapter 1

Book III, Chapter 01 | 02 | 03 | 04 | 05 | 06

From these things, however, it must be considered which of two, or of many things, is the more eligible, or better. But this in the first place is to be determined, that we do not make those things the subject of consideration which are much distant, and greatly differ from each other; (for no one doubts whether felicity or wealth is th¢ more eligible) but those which are near, and concerning which we are dubious whether it is necessary that the article more should be added, because we see no transcendency of the one with reference to the other. It is evident, therefore, in these, that one or many excellencies being demonstrated, the reasoning power will concede that this is the more eligible, whichever of them it may be that excels. In the first place, therefore, that which exists for a longer space of time, is more eligible than that which has a less extended duration. Likewise that is more eligible  which a wise or a good man would rather choose, or upright law, or which the studious about each particular would prefer, so far as they are studious, or the scientific in each genus of things, or such as most or all would choose; as in the medical, or carpenter’s art, such things as most, or all physicians would choose; or such things, in short, as most, or all men, or all things would choose, as, for instance, good; for all things desire good. It is necessary, however, to bring what will be said, to that which is useful. But simply, that is better and more eligible, which is accordirig to the better science. Thus, if the philosophical is better than the tectonic science; things pertaining to philosophy are also simply more eligible than things pertaining to the tectonic science; but to a certain person, that is more eligible which is according to his proper science. In the ·next place, that which is in genus, is more eligible  than that which is not in genus; as justice is more eligible than a just man. For the former is in genus, i.e. in good; but the latter is not. And the one is that which is good, but the other is not. For nothing is said to be that which genus is, which is not in genus. Thus a white man is not that which colour is; and in a similar manner in other things. That also which is eligible for its own sake, is more eligible than that which is the object of choice for the sake of something else. Thus, to be well is more eligible than to be exercised; for the former is eligible for its own sake, but the latter for the sake of something else. And that which is per se, is more eligible than that which is according to accident; as, for instance, it is more eligible that friends than that enemies should bejust. For the former is eligible per se; but the latter from accident. For we wish our enemies to be just from accident, in order that they may not injure us. This place, however, is nearly the same as that which is prior to it, but it differs in the mode. For we wish that our friends may be just for their own sake, though we should derive no advantage from it, and though they should be at India; but we wish that our enemies may be just, for the sake of something else, viz.that they may do us no injury. That also which is the cause of good per se, is more eligible than that which is the cause from accident; just as virtue is more eligible than fortune. For the former is the cause of good per se; but the latter from accident. And likewise, if there is any thing else of this kind. This will also be the case, in the contrary to the eligible. For that which is per se the cause of evil, is more to be avoided than that which is the cause from accident; as, for instance, vice and fortune: For the former is evil per se; but fortune, from accident. And that which is simply good is more eligible than that which is good to a certain person; as, to be well, than to be cut. For the former is simply good; but the latter is good to some one who requires to be cut. That also which is good by natureis more eligible than that which is not naturally good; as, for instance, justice, than ajust man. For the former is naturally good; but the good of the latter is acquired. That likewise which is present with a better and more honourable nature is more eligible. Thus, that which is present with God is more eligible than that which is present with man; and that which is present with the soul, than that which is present with the body. The peculiarity also of the better nature is more excellent than the peculiarity of the subordinate nature; as, for instance, the peculiarity of God than the peculiarity of man. For according to those things which are common in both, they do not differ from each other; but in peculiarities the one differs from the other. That also which is in better, or in prior, or in more honourable natures is better, as liealtb is better than strength and beauty. For the former is in things moist and dry, hot and cold, and, in short, in those things from which primarily the animal consists; but the latter arein things posterior. For strength is in the nerves and bones; but beauty appear to be a certain symmetry of the members. The end likewise appears to be more eligible than things which lead to the end; and of two things, that which is nearer to the end. And, in short, that which contributes to the end of life, is more eligible than that which contributes to some other end. Thus, that which contributes to felicity is more eligible than that which contributes to prudence. And the possible is more eligible than the impossible. Again, when two things are effective, that of which the end is better, is itself better. That, however, which is effective, and that which is the end, are to be considered from the analogous; when one end more abundantly surpasses another, than the effect its proper efficient’ cause. Thus, if felicity more abundantly surpasses health, than health surpasses the salubrious; that which is productive of felicity will be better than health. For by how much felicity surpasses health, by so much does that which is productive of felicity, surpass the salubrious. But health less surpasses the salubrious, than felicity surpasses health. Hence that which is productive of felicity, more abundantly surpasses the salubrious, than health surpasses the salubrious. It is evident, therefore, that what is productive of felicity, is more eligible than health; for it more abundantly surpasses the same thing. Farther still, that is more eligible which is more beautiful per se, and is more honourable and laudable. Thus, friendship is more eligible than wealth, and justice than health and strength. For the former are per se among the number of things honourable and laudable; but the latter, not per se, but for the sake of something else. For no one honours wealtli on its own account, but for the sake of something else. But we choose friendship per se, though we should obtain nothing else from it in future.

Aristotle, Topics. Book III, Chapter 2

Again, when two certain things are very similar to each other, and we cannot perceive any excellence of the one with respect to the other, we must see whether it can be understood from things consequent. For that to which the greater good is consequent is more eligible. But if the things consequent are evil, that to which the less evil is consequent, is the more eligible. For both being eligible, nothing hinders but that something troublesome may follow. The consideration, however, from consecution is twofold. For it follows, both prior and posterior; as to the learner, ignorance is prior, but science posterior. But for the most part, that which is posterior in consecution is better. Hence it is necessary to take whichever of consequents may be useful. Farther still, many are to be preferred to fewer goods, either simply or when some are inherent in others, viz. the fewer in the few. But here it may be objected, that if anywhere, one thing is for the sake of another, both are not more eligible than one. Thus, for instance, to be made well, and health, are not preferable to health; since we choose to be made well for the sake of health. Nothing prevents, however, things which are not good, in conjunction with such as are good, from being more eligible. Thus, felicity and something else which is not good, may be more eligible than justice and fortitude. And the same things in conjunction with pleasure, are more eligible than without pleasure. The same things also in conjunction with a privation of pain, are more eligible than in conjunction with pain. And every thing, at the time in which it possesses greater power, is more eligible. Thus, to live without pain in old age, is more eligible than to live without pain in youth; for it is capable of effecting greater things in old age. Thus also, prudence in old age is more eligible; for no one chooses young men as leaders, because they are not considered as prudent. The contrary, however, takes place in fortitude; for in a young man the energy according to fortitude is more necessary. And in a similar manner with respect to temperance; for young men are more disturbed by desires than elderly men. And that which is useful at every time, or in most times, is the more useful. Thus, justice and temperance are more useful than fortitude; for the former are always, but the latter is sometimes useful. That also, which all men possessing, we should require nothing else, is more eligible, than that which when possessed by all men, we should be in want of something else; as may be seen in justice and fortitude. For if all men were just, fortitude would not be at all useful. But though all men were courageous, justice would be useful. Again, arguments are to be derived from corruptions, rejections, generations, assumptions, and contraries. For those things of which the corruptions are more to be avoided, are themselves more eligible. And in a similar manner in rejections, and contraries. For that of which the rejection, or the contrary to which, is to be avoided, is itself more eligible. But the contrary takes place in generations and assumptions. For those things of which the generations and assumptions are more eligible, are themselves more eligible. Another place, is as follows: That which is nearer to the good, is better and more eligible. And also that which is more similar to the good; as, justice, than a just man. Likewise that which is similar to the better of them; as some say that Ajax was better than Ulysses, because he was more similar to Achilles. The objection to this is, that it is not true; for nothing prevents Ajax from being more similar to Achilles, not so far as Achilles was the better character; the one (Ulysses) being a good man, and yet not similar to Achilles. It is also requisite to consider whether there will be the similar in things which are more ridiculous, as an ape resembles a man, though a horse does not; for an ape is not more beautiful, but more similar to man. Again in two things; if the one is more similar to that which is better, but the other to that which is worse; that will be the better of the two, which is more similar to that which is better. There is, however, an objection to this; for nothiug hinders but that the one may be in a small degree similar to that which is better, and the other may be very similar to that which is worse; as, if Ajax is in a small degree similar to Achilles, but Ulysses is very similar to Nestor. Also, if that which is similar to the better, is similar so far as pertains to what is worse; but that which is similar to the worse, is similar so far as pertains to what is better; as a horse with respect to an ass, and an ape with respect to a man. Another place: That which is more illustrious is more eligible, than that which is less so. And likewise, that which is more difficult. For the possession of those things is dearer to us, which cannot easily be obtained. That which is more peculiar also is more eligible than that which is more common. That also is more eligible which has less communion with evils. For that is more desirable which is followed by no molestation, than that to which molestation is consequent. Farther still, if this thing is simply better than that; that also which is simply the best in this, is better than that which is best in the other. Thus, if a man is better than a horse, the best man is better than the best horse. And if the best is better than the best, this also is simply better. Thus, if the best man is better than the best horse, man simply considered is likewise better than horse simply considered. Again, those things of which it is possible to partake in conjunction with friends, are more eligible than those of which friends cannot partake. Those things also which we rather wish to do for a friend, are more eligible than those we wish to do for any casual person. Thus, to act justly, and to do good, are more eligible than to seem to do so; for we rather wish to benefit our friends, than to seem to benefit them; but vice versa with respect to casual persons. Things likewise which are from the abundant, are better than such as are necessary, and sometimes they are also more eligible. For to live well is better than merely to live; but to live well is from the abundant; and to live is a thing necessary. But sometimes things which are better, are not more eligible; for it is not necessary if they are better that they are also more eligible. For to philosophize is better than to acquire money, yet it is not more eligible to him who is in want of necessaries. But a subsistence from the abundant then takes place, when necessaries being supplied, certain other things which rank among such as are beautiful, are also procured. Perhaps, too, that which is necessary is nearly more eligible; but that which is from the abundant is better. That also which cannot be supplied by ahother, is better than that which another may also supply; and such is justice with respect to fortitude. And if this thing is eligible without that, but not also that without this. Thus, power without prudence is not eligible, but prudence is eligible without power. Likewise, if we deny one of two things, in order that the other may appear to be present with us; that is the more eligible which we wish may appear to be present with us. Thus we deny that we are laborious, in order that we may appear to have genius. Again, that, the absence of which when it is borne with difficulty is less reprehensible, is more eligible; and that, the absence of which when it is not borne with difficulty is more reprehensible, is
also more eligible.

Aristotle, Topics. Book III, Chapter 3

Again, of those things which are under the same species, that which has its proper virtue, is more eligible than that which has not. But when it is possessed by two things, that is more eligible, which has it in a greater degree. Farther still, if one thing causes that to be good with which it is present, but another does not; that which produces good, is the more eligible; just as that which heats is hotter than that which does not. But if both cause that to be good, with which they are present; that is more eligible which causes it in a greater degree; or which causes a better and more principal thing to be good; as, if one thing causes the soul to be good, but another the body. Again, particulars are to be confirmed from cases, uses, actions and works, and these from those. For they follow each other. Thus, if the justly is more eligible than the courageously; justice also is more eligible than fortitude. And if justice is more eligible than fortitude, the justly is also more eligible than the courageously. The like also takes place in other things. Farther still, if of the same thing, one thing is a greater good, but another a less; the greater good is the more eligible. Or if it is the good of that which is more excellent, it will be a greater good. But also if two things are more eligible than a certain thing, that which is the more eligible is to be preferred to that which is less eligible. Farther still, that of which the excess is more eligible than the excess of another thing, is itself more eligible. Thus, friendship is more eligible than riches; for the excess of friendship is more eligible than the excess of riches. That also is more eligible, which a man would rather procure through himself, than that which he procures through another; as, for instance, friends than riches. Again, it must be considered from addition, if any thing being added to the same thing, makes the whole to be more eligible. It is necessary, however, to be careful, lest those things should be proposed, in which that which is common is used in one of the added particulars, or in some other way co-operates with it. Thus, if a saw and a sythe are added together with the tectonic art, the saw when conjoined is more eligible, but simply considered it is not more eligible. Again, it must be considered if any thing being added to the less, causes the whole to be greater. The like also must be considered from ablation. For when any thing being taken away from the same thing, that which remains is less, that which was taken away will be greater; since that which was taken away, causes that which remain; to be less. And if the one is eligible for its own sake, but the other on account of renown; as health is more eligible than beauty. But the definition of that which is eligible on account of renown is, that if no one were conscious, we should not endeavour to obtain it. Likewise, if the one is eligible for its own sake, and on account of renown; but the other on account of one of them only. And that which is more honourable for its own sake, is better and more eligible. But that will be more honourable per se, which when it will not in future be attended with any thing else, we should rather prefer for its own sake. Again, it is necessary to distinguish in how many ways the eligible is predicated, and for the sake of what; as, for the sake of the profitable, or the beautiful, or the pleasant. For:that which is useful to all, or to many things, will be more eligible than that which is not similarly useful. But when the same things are present with both, it must be considered with which they are more present; as, whether it is the more pleasant, or the more beautiful, or the more profitable. Again, that which is for the sake of what is better is more eligible. Thus, that which is for the sake of virtue is more eligible than that which is for the sake of pleasure. The like also takes place in things which are to be avoided. For that is more more to be avoided which is more an impediment to things that are eligible; as, disease than deformity. For disease is a greater impediment both to pleasure and probity. Farther still, another place is derived from the ability of similarly demonstrating that the thing proposed is to be avoided and chosen. For a thing which is of that kind, that it may be similarly chosen and avoided, is less eligible than another thing which is eligible only. The comparisons, therefore, of things with each other, as we have said, must be made.

Aristotle, Topics. Book III, Chapter 4

The same places, however, are useful for the purpose of showing that any thing is to be chosen or avoided. For it is alone necessary to detract the excellence, by which one thing surpasses another. For if that which is more honourable, is more eligible; that also which is honourable is eligible. And if that which is more useful is more eligible; that also which is useful is eligible. The like also takes place in other things, which have such a comparison. But in some things, by making a comparison of one with the other, we immediately say that each, or that one of them, is eligible; as when we say that one thing is naturally, but another is not naturally good. For that which is naturally good is evidently eligible.

Aristotle, Topics. Book III, Chapter 5

But places in the most eminent degree universal, are to be assumed of the more and the greater; for when thus assumed, they will be useful to many problems. It is possible, however, to render some of those we have mentioned more universal, by changing in a small degree the appellation. Thus, that which is such by nature, is more such than that which is not such by nature. And, if the one causes, but the other does not cause the thing which possesses that to be such, or that in which it is inherent; that which is sometimes the cause, is more a thing of this kind, than that which is not the cause. But if both are causes, that which is more the cause, is a thing of this kind. Again, if of the same thing, one thing is more, but another less such; and if the one of a thing of this kind is more such, but another is not of such a thing more such; it is evident that the first is more a thing of this kind. Again, a place is also to be derived from addition, if something being added to the same thing, causes the whole to be more such. Or if that which is less added to a thing of this kind, causes the whole to be more such. In a similar manner also from ablation; for that which when taken away, what remains is less such, is itself more such. Things also which are more unmingled with contraries, are themselves more such; as, that is whiter which is more unmingled with black. In addition likewise to what has been before said, there is that which receives in a greater degree the proper definition of the thing proposed. Thus, if the definition of whiteness is colour which has the power of separating the sight; that is more white, which is in a greater degree colour having the power of separating the sight.

Aristotle, Topics. Book III, Chapter 6

If, however, the problem should be posited partially and not universally; in the first place, all the before-mentioned universal places which confirm or subvert, are useful. For when we universally subvert or confirm, we also partially demonstrate; since if a thing is present with every individual, it is also present with a certain individual; and if it is not present with any, neither is it present with a certain individual. But those places are especially appropriate and common, which are assumed from opposites, from things co-ordinate, and from cases. For it is similarly probable to assume, that if every pleasure is good, all pain is likewise an evil; and that if a certain pleasure is good, a certain pain is also an evil. Again, if a certain sense is not a power, a certain privation of sense is not impotence. And if a certain thing which is the object of opinion, is also the object of science, a certain opinion is science. Again, if any thing unjust is good, something just is also evil. And if any thing which is done unjustly is evil, something also which is done justly is good. If, likewise, something pleasant is to be avoided, a certain pleasure also is to be avoided. Hence too, if any thing pleasant is advantageous, a certain pleasure also is good. The like also takes place in things which have the power of corrupting, and also in generations and corruptions. For if any thing which has the power of corrupting pleasure or science is good, a certain pleasure or science will be among the number of things evil. In a similar manner also, if a certain corruption of science is among the number of things good, or a certain generation is among the number of things evil; a certain science will be among the number of things evil. Thus, if to forget the base actions which any one has performed, is among the number of things good, or to recollect them is among the number of things evil; to know the base actions which some one has performed, will be among the number of evils. The like also takes place in other things; for in all of them there is a  imilar probability. Farther still, another useful place, is from the more, the less, and the similarly. For if any one of those things which ate from another genus is more such, but no one of this genus is such, that which was mentioned in the problem will not be a thing of this kind. Thus, if a certain science is more a good than pleasure, but no science is good, neither will pleasure be good. After the same manner also, from the similarly and the less; for it will be possible, both to subvert and confirm; except that it is possible from the similarly to do both. But from the less, it is only possible to confirm, and not to subvert. For if a certain power and science are similarly good, but a certain power is good, a certain science also is good. But if no power, neither is any science good. If, however, a certain power is less a good than science, but a certain power is good, a certain science also is good. But if no power is good, it is not also necessary that no science should be good. It is evident, therefore, that it is only possible to confirm from that which is less. It is not only possible, however, to subvert from another genus, but also from the same genus, by assuming that which is especially such. Thus, if it should be admitted that a certain science is good, but it should be shown that prudence is not good, neither will any other science be good, since that which especially appears to be good is not good. Farther still, the same thing is effected from hypothesis, when in a similar manner it is assumed, that if a thing is present, or is not present with one thing, it is also present, or not present, with all things; as, if the soul of man is immortal, that other souls also are immortal; but if this is not immortal, that neither are other souls immortal. If therefore, a thing is posited to be present with a certain thing, it must be shown that it is not present with a certain thing; for it will follow from the hypothesis that it is not present with any thing. But if it is posited not to be present with a certain thing, it must be shown that it is present with a certain thing. For thus it will follow that it is present with all. But it is evident that he who makes this hypothesis, causes the problem to be universal, which was posited to be partial. For he thinks fit to acknowledge that to be universal, which was conceded to be partial; because if it is present with one thing, he thinks that it should be similarly present with all. The problem, therefore, being indefinite, it may in one way be subverted; as if he should say, that pleasure is good, or is not good, and should not in defining add any thing else. For if it should be said that a certain pleasure is good, it must be shown universally that no pleasure is good, if the thing proposed is to be subverted. In a similar manner also if it should be said, that a certain pleasure is not good, it must be shown universally that all pleasure is good; for otherwise it will not be possible to subvert the problem. For if we should show that a certain pleasure is not good, or that a certain pleasure is good, the thing proposed will not yet be subverted. It is evident, therefore, that it is possible to subvert in one way, but to confirm in a twofold respect. For whether we universally show that all pleasure is good, or that a certain pleasure is good, the thing proposed will be proved. In a similar manner, if it should be requisite to show that a certain pleasure is not good, if we prove that no pleasure is good, or that a certain pleasure is not good, we shall have proved in both ways, as well universally as partially, that a certain pleasure is not good. But the thesis being defined, it will be possible to subvert in a twofold respect; as, if it should be posited that good is present with a certain pleasure, but with a certain pleasure is not present. For whether it be shown that all pleasure, or that no pleasure is good, the thing proposed will be subverted. If, however, it is admitted, that one pleasure only is good, it may be subverted in a threefold respect. For by showing that all, or that no pleasure is good, or that more pleasures than one are good, we shall have subverted the thing proposed. When, however, the thesis is defined to a greater extent, as, that prudence alone among the virtues is a science, it will be possible to subvert in a fourfold respect. For by showing that every virtue is a science, or that no virtue, or some other virtue, is a science, as, justice, or that prudence itself is not a science, the thing proposed will he subverted. It is also useful to direct our attention to particulars, in which something was said to be inherent, or not, as in universal problems. Again, we should also direct our attention to genera, by dividing according to species as far as to individuals, as we before observed. For whether a thing should appear to be present with every, or with no individual, many things being adduced, the opponent must be desired to concede universally, or to bring an objection in what particular thing it is not so. It must likewise be considered, in what things it is possible to distribute accident, either in species, or in number, if it is present with no one of these. Thus, if we wish to prove that time is not moved, and that it is not motion, we must enumerate how many species there are of motion. For if no one of these is present with time, it is evident that time is not moved, and that it is not motion. In a similar manner also, if we wish to prove that the soul is not number, we must show by division that every number is either odd or even. For if the soul is neither odd nor even, it is evident that it is not numbers. In order, therefore, to confirm, or subvert accident, we must argue through such places and after this manner.

Aristotle, Topics. Book IV, Chapter 1

Book IV, Chapter 01 | 02 | 03 | 04 | 05 | 06

After these things, we must direct our attention to what pertainsn to genus and peculiarity. But these are the elements of things which pertain to definitions; and these are seldom considered by those who dispute. If, therefore, it should be posited that there is a genus of a certain thing, we must in the first place direct our attention to whatever is allied to that thing, that we may see whether it is not predicated of a certain thing as is the case in accident. Thus, if good should be posited to be the genus of pleasure, it must be considered whether a certain pleasure is not good. For if this should be said, it is evident that good is not the genus of pleasure; because genus is predicated of all the species contained under it. In the next place, it must be considered whether it is not predicated in answer to the question what a thing is, but is predicated as accident, just as whiteness is predicated of snow, or that which is moved from itself is predicated of the soul. For neither is snow the same thing as whiteness; on which account whiteness is not the genus of snow; nor is the soul the same thing as that which is moved; but it happens to it to be moved, just as it frequently happens to an animal to walk, and to be walking. Farther still, the being moved is not a certain essence, but appears to signify something active or passive. The like also takes place in whiteness; for it does not manifest what snow is, but what kind of thing it is. Hence neither of these is predicated in answer to the question what a thing is. But it is especially necessary to direct our attention to the definition of accident, and to see whether it is adapted to that which is said to be a genus; as, for instance, in what has been just now mentioned. For it is possible that a certain thing may move itself, and that it may not move itself, and in a similar manner that it may be white and not white. Hence neither of these is genus, but accident; since we call that accident, which may be present and not present with a certain thing. Again, it must be considered whether genus and species are not in the same division; but the one is essence, and the other is quality; or the one is a relative, but the other is quality. Thus, for instance, snow is essence, and also a swan; but whiteness is not essence, but quality. Hence whiteness is neither the genus of snow, nor of a swan. Again, science is among the number of relatives; but good is a quality, and also the beautiful. Hence neither the good, nor the beautiful is the genus of science. For it is necessary that the genera of relatives should also be themselves relatives; as is evident in the double. For the multiple, since it is the genus of the double, is also itself among the number of relatives. And universally, it is necessary; that genus should be under the same division: with species. For whether species is essence, genus also is essence; or whether species is a certain quality, genus also is a certain quality. Thus, if whiteness is a certain quality, colour also is a certain quality. The like also takes place in other things. Again, it must be considered whether it is necessary or contingent that genus participates of that which was posited in genus. But the definition of participating is to receive the definition of that which is participated. It is evident, therefore, that species participate of genera; but that genera do not participate of species. For species receives the definition of genus; but genus does not receive the definition of species. It must be considered, therefore, whether the proposed genus participates, or can participate of species; as, if some one should assert that there is a certain genus of being, or the one. For it happens that genus participates of species; since being and the one are predicated of all beings; so that the definition of them also is predicated of all beings. Farther still, it must be considered whether the assigned species is truly predicated of a certain thing, but not the genus; as if it were posited that being, or the object of scientific knowledge, is the genus of that which is the object of opinion. For that which is the object of opinion is predicated of non-being; since many things which have no existence are the objects of opinion. But that being, or the object of scientific knowledge, is not predicated of non-being is evident. Hence, neither being, nor the object of scientific knowledge, is. the genus of that which is the object of opinion; for of those things of which species are predicated, it is also necessary that genus should be predicated. Again, it must be considered, whether that which is posited in the genus, can participate of no species. For it is impossible that that which participates of no species, should participate of genus, unless it should be some one of those species, which are posited in the first division af genus. But these alone participate of genus. If, therefore, it should be posited that motion is the genus of pleasure; it must be considered whether pleasure is neither corruption, nor change in quality; nor any one of the other assigned motions; for it is evident that it participates of none of the species of motion, and, therefore, does not participate of the genus, since it is necessary that the participant of genus, should also be a participant of some species. Hence pleasure, will not be a species of motion, nor an individual motion, nor will it rank among those things which are under a species of motion. For individuals also participate of genus and species; as, a certain man, participates both of man and animal. Again, it must be considered, whether that which is posited in genus is more widely extended than genus. Thus, the object of opinion is more widely extended than being; for both being and non-being are objects of opinion. Hence, the object of opinion will not be a species of being; for genus is always more widely extended than species. Again, it must be considered whether genus and species are predicated of the same number of things; as, if among the number of things consequent to all things, one should be posited as genus, but another as species; as, being, and the one. For being and the one are consequent to every thing; so that neither is the genus of the other, since they are predicated of the same number of things. The like will also take place, with respect to that which is first and the principle, if the one should be placed under the other; for principle is that which is first; and that which is first is principle. Hence both these are the same, or neither is the genus of the other. The element, however, with respect to all such things is, that the predication of genus is more widely extended than that of species and difference; for difference also is predicated of fewer things than genus. It is likewise requisite to see whether what has been mentioned is not, or does not appear to be the genus of some one of those things which do not differ in species. But he who confirms will see whether it is the genus of some one of these. For there is the same genus of all those things which do not differ in species. If, therefore, it is shown that it is the genus of one of these, it is evident, that it is the genus of all of them; and if not of one, it is evident that it is not of any; as, if some one admitting that there are indivisible lines, should say that the genus of them is indivisible. For what has been mentioned is not the genus of lines which may be divided, since they have no specific difference; for all right lines do riot differ from each other according to species.

Aristotle, Topics. Book IV, Chapter 2

It is also requisite to consider whether there is a certain other genus of the assigned species, which neither contains the assigned genus, nor is under it; as if some one should assert that science is the genus of justice. For virtue also is the genus of it; and neither of these genera, comprehends the other; so that science will not be the genus of justice. For it seems that when one species is under two genera, the one is comprehended under the other. A thing of this kind, however, is dubious in certain things. For to some prudence appears to be virtue and science, and that neither of the genera is comprehended under the other. It is not, however, admitted by all men that prudence is science. If, therefore, any one grants that what has been said is true; it will appear to be necessary that those things which are genera of the same thing, are either subaltern, or both are under the same genus; just as it happens in virtue and science; for both are under the same genus; because each of them is a habit and disposition. Hence it must be considered whether neither of them is present with the assigned genus. For if they are neither subaltern genera, nor both are under the same genus, that which is assigned will not be a genus. It is also necessary to consider the genus of the assigned genus, and thus always the superior genus, viz. whether all things are predicated of the species, and whether they are predicated in answer to the question what a thing is. For it is necessary that every superior genus should be predicated of species in answer to the question what a thing is. If, therefore, it is anywhere discordant, it is evident that the thing assigned is not a genus. Again, it must be considered, whether genus participates of species, either itself, or some one of the superior genera. For the superior genus participates of no one of the inferior genera. Hence he who subverts, must, as we have said, use this place. But to him who confirms, if it is admitted that the proposed genus is present with species, but it is dubious whether it is present as genus, it will be sufficient to show that some one of the superior genera is predicated of species in answer to the question what a thing is. For one thing being predicated in answer to the question what a thing is, all above and beneath this, if they are predicated of species, will be predicated in answer to the question what a thing is; so that the assigned genus likewise will be predicated in answer to the same question. But that if one is predicated in answer to the question what a thing is, all the rest, if they are predicated, will be predicated in answer to the same question, must be assumed through induction. If, however, it should be simply doubted whether the assigned genus is inherent, it is not sufficient to show that some one of the superior genera is predicated of species in answer to the question what a thing is. Thus, if some one should assert that lation is the genus of walking, it is not sufficient to show that walking is motion, in order to prove that it is lation, since there are also other motions; but at the same time it is demonstrated that walking participates of no one of the motions which are in the same division, except lation. For it is necessary that the participant of genus, should also participate of some one of the species which are in the first division of the genus. If, therefore, walking neither participates of increase, nor diminution, nor of the other motions, it is evident that it participates of lation; so that lation will be the genus of walking. Again, in those things in which the proposed species, is predicated as genus, it is necessary to consider, whether the assigned genus also is predicated of those things of which species is predicated in answer to the question what a thing is. And in a similar manner this must be considered in all those things which are above the genus. For if there is anywhere a disagreement, it is evident that the thing proposed is not a genus. For if it were a genus, every thing which is above this, and this very thing itself, would be preclicated in answer to the question what a thing is, of those things in which species also is predicated in answer to the same question. Hence to him who subverts it is useful, if genus is not predicated in answer to the question what a thing is, of those things of which species likewise is predicated. But to him who confirms it is useful if it is predicated in the question what a thing is. For it will happen that both genus and species will be predicated of the same thing, in the question what a thing is. Hence the same thing is under two genera. It is necessary, therefore, that the genera should be subaltern. If, therefore, it should be demonstrated that the thing, which we wish to constitute the genus, is not under species, it is evident that species will be under it. Hence it will be proved that this is a genus. It is likewise necessary to consider the definitions of genera, whether they are adapted to the assigned species, and to the participants of species. For it is necessary that the definitions of genera should be predicated of species, and of the participants of species. Hence, if there is anywhere a disagreement, it is evident that the thing assigned is not a genus. Again, it must be considered whether difference is assigned as a genus; as, whether the immortal is assigned as the genus of God. For the immortal is the difference of animal; because of animals, some are mortal, but others immortal. It is evident, therefore, that he who assigns difference as a genus errs; for difference is not the genus of any thing. But that this is true is evident. For no difference signifies what a thing is, but rather what kind of a thing it is, as terrestrial and biped. It must likewise be considered whether difference is posited in genus, as if it were species; just as if it should be said, that the odd is that which is number. For the odd is a difference and not a species of number. Nor does difference appear to participate of genus. For every thing which participates of genus, is either species, or an individual; but difference is neither species, nor an individual. It is evident, therefore, that difference  does not participate of genus. Hence, neither will the odd be species, but difference, since it does not participate of genus. Again, it must also be considered whether genus is posited in species; as if it should be said that conjunction is continuity; or that mixture is temperament; or according to the definition of Plato, that motion according to place is lation. For it is not necessary that conjunction should be continuity, but on the contrary that continuity should be conjunction. For not every thing which touches is continued; but every thing which is continued touches. The like also takes place in the rest. For neither is all mixture  emperament; since the mixture of dry things is not temperament; nor is all mutation according to place lation; for walking does not appear to be lation. For nearly, lation is asserted of those things which involuntarily change their place, as happens to be the case with inanimate natures. But it is evident that the predication of species is more widely extended than that of genus, in the things which have been adduced, though the contrary ought to take place. Again, it must be considered, whether difference is posited in species; as, that the immortal is that which God is. For it will happen that species will be predicated of the same number, or of a greater number of things; since difference is always predicated equally with, or to a greater extent than species. Farther still, it must be considered, whether genus is posited in difference; as, that colour is that which congregates, or that number is that which is odd. Likewise whether genus is spoken of, as if it were difference. For it is possible that some one may also introduce a thesis of this kind; as, that mixture is the difference of temperament; or that motion according to place ist he difference of lation. All such particulars, however, must be considered, through the same things; (for places communicate with each other) and it is necessary that genus should be predicated to a greater extent than difference, and should not participate of difference. But genus being thus assigned, as in the before-mentioned examples neither of the things which have been mentioned can happen; for they will be predicated of fewer particulars, and genus will participate of difference. Again, if no one of the differences of genera is predicated of the assigned species, neither will genus be predicated of it. Thus, neither the odd nor the even is predicated of the soul; and, therefore, neither is number predicated of it. Farther still, if species is prior by nature, and co-subverts genus (for the contrary appears to be true) it will not be genus. Again, if it is possible that species may relinquish the proposed genus, or difference, as, that to be moved may relinquish the soul, or the true and the false, opinion, neither of the thinsg which have been mentioned will be genus or difference. For it appears that genus and difference are consequent, as long as species exists.

Aristotle, Topics. Book IV, Chapter 3

It is likewise necessary to consider whether that which is posited in genus participates, or can participate of something contrary to genus; for the same thing will at the same time participate of contraries; since species never relinquishes genus; but participates, or is capable of participating in that which is contrary. Farther still, it must be considered, whether species communicates with any thing which cannot be present with those things which are under genus. Thus, if the soul participates of life, but no number is able to live; . The soul will not be a species of number. It must likewise be considered whether species is homonymous with genus, employing for the purpose of investigating the homonymous, the before-mentioned elements; genus and species are synonymous. Since, however, there are many species of every genus, it must be considered, whether there may not be another species of the proposed genus. For if there is not, it is evident that the thing spoken of, will not, in short, be genus. It is also requisite to consider, whether that which is spoken of metaphorically, is proposed as genus; as, if it should be said, that temperance is symphony. For every genus is properly predicated of species; and symphony is not properly predicated of temperance, but metaphorically. For all symphony is in sounds. Again, it must be considered, whether a certain thing is contrary to species. But this consideration is multifarious. In the first place, indeed, it must be considered, whether there is also a contrary in the same genus, when there is not a contrary to genus. For it is necessary that contraries should be in the same genus, if nothing is contrary to genus. But if there is anything contrary to genus, it is  requisite to consider whether the contrary is in a contrary genus. For it is necessary that the contrary should be in the contrary, if any thing is contrary to genus. Each of these, however, is manifest through induction. Again, it must be consideied, whether that which is contrary to species is, in short, in no genus, but is itself a genus; as, for instance, the good. For if this is not in genus, neither will the contrary to this be in genus, but it will be itself a genus; as it happens in good and evil. For neither of these is in genus, but each of them is a genus. Farther still, it must be considered whether as well genus as species is contrary to a certain thing; and whether there is a certain thing between some things; but not between others. For if there is something between genera, there is also something between species; and if between species, there is likewise between genera; as in virtue and vice, justice and injustice; for between each of these then is something intermediate. To this, however, it may be be objected, that there is nothing between health and disease, but that there is something between good and evil. Again, it must be considered whether there is something between both, that is, between species and genera: yet not similarly; but between the one according to negation, and between the other as a subject. For it is probable that something similarly intervenes between both; as, in virtue and vice, justice and injustice; for there is a medium between both according to negation. Farther still, when there is not a contrary to genus, it must be considered, not only whether the contrary is in the same genus, but also whether the medium is in the same genus. For the medium is in the same genus in which the extremes are; as, for instance, in white and black. For color is the genus of these, and of all intermediate colors. It may, however, be objected, that defect and excess are in the same genus; for both are in that which is evil. But the moderate which is a medium between these, is not in that which is evil, but in that which is good. It is likewise requisite to consider whether genus is contrary to a certain thing, but species to nothing. For if genus is contrary to a certain thing, species is likewise; as, virtue and vice, justice and injustice. In a similar manner also, to him who considers other things, a thing of this kind will appear to be evident. The objection to it, however, is in health and disease. For simply health is contrary to disease; but a certain disease, since it is a species of disease, is not contrary to anything; as, for instance, a fever, and ophthalmy, and every other disease. By him, therefore, who subverts, these things must be considered in so many ways. For if the particulars which have been mentioned are not inherent, it is evident that the thing assigned is not a genus. But by him who confirms, these things must be considered in a threefold respect. In the first place, indeed, whether that which is contrary to species, is in the above mentioned genus, when there is not a contrary to the genus. For if the contrary is in this genus, it is evident that the thing proposed is also in the same genus. Again, it must also be considered, whether the medium is in the before mentioned genus; for in that in which the media are contained, in that also are the extremes. Again, if a certain thing is contrary to genus, it must be considered, whether also the contrary is in the contrary.  For if it is, it is evident that the proposed species is in the proposed genus.

Aristotle, Topics. Book IV, Chapter 4

Again, it must be considered in cases and things coordinate, both by him who subverts, and him who confirms, whether they are similarly consequent. For at one and the same time, they are present,  or are not present with one and with all things. Thus, if justice is a certain science; that which is done justly, is also done scientifically; and a just is a scientific man. But if some one of these is not so, neither is any one of the rest. Again, those things must be considered, which are similarly affected with respect to each other. Thus the pleasant subsists with reference to pleasure, similarly to the useful with reference to good; is is effective. If, therefore, pleasure is that which is good, the pleasant also will be that which is useful. For it is evident that it will be effective of good, since pleasure is good. The like also takes place in generations and corruptions. Thus, if to build is to energize, to have built is to have energized. And if to learn is to remember, to have learned is to have remembered. If also to be dissolved is to be corrupted, to have been dissolved is to have been corrupted; and dissolution is a certain corruption. In a similar manner likewise, it must be considered both by him who subverts and him who confirms, in things which have the power of generating, and also in those which have the power of corrupting; likewise in powers and uses, and, in short, according to any kind of similitude, as we have observed in generation and corruption. Or if that which is corruptive has a dissolving power, to be corrupted is to beb dissolved. And if that which is generative is effective; to be generated is to be made; and generation is making. The like also takes place in powers and uses. And, in short, if power is disposition, to be able is to be disposed. And if the use of a certain thing is energy; to use is to energize; and to have used is to have energized. But if that which is opposed to species is privation, it is possible to confute in a two-fold respect. In the first place, indeed, if that which is opposed is in the assigned genus. For either simply privation is in no genus which is the same, or it is not in the same extreme genus. Thus, if site is in sense, as in the extreme genus, blindness will not be sense. In the second place, if privation is opposed both to genus and species, but the thing opposed is not in the thing opposed, neither will the thing assigned be in the thing assigned. Buy him who subverts, therefore, this place must be used, in the manner we have mentioned. But by him who confirms, it must be used in one way. For if the thing opposed is in the thing opposed, the thing proposed will also be in the thing proposed. Thus, if blindness is a certain privation of sense; sight also is sense. Again, negations must be considered in an inverse order, as it was observed in accident. Thus, if the pleasant is that which is good, that which is not good is not pleasant. For if it were not so, something which is not good would be pleasant. It is, however impossible, if the good is the genus of the pleasant, that something which is not good should be pleasant. For of those things of which genus is not predicated, neither will any species be predicated. In a similar manner also, it must be considered by him who confirms. For if that which is not good, is not pleasant; the pleasant is good; so that the good is the genus of the pleasant. But if species is a relative, it must be considered whether genus also is a relative. For if species is among the number of relatives, genus is also, as is evident in the double or the multiple; for each of these is a relative. If, however, genus is a relative, it is not also necessary that species should be a relative. For science is among the number of relatives, but grammar is not. Or shall we say, that neither does that which was before asserted appear to be true? Or virtue is that which is good, and that which is beautiful; and virtue, indeed is among the number of relatives; but the good and the Beautiful are not relatives, but qualities. Again, it must be considered whether species is not referred to the same thing, per se, and according to genus. Thus, if the double is said to be the double of the half, it is also necessary that the multiple should be said to be the multiple of the half. For if not, the multiple will not be the genus of the double. Farther still, it must be considered whether it is not referred to the same thing, both according to genus, and according to all the genera of genus. For if the double and the multiple are predicated with reference to the half; to exceed will also be predicated of the half; and, in short, according to all the superior genera, there will be a reference to the half. It may, however, be objected, that a reference to the same thing is not necessary per se, and according to genus. For science is said to be the science of that which is the object of science, but have it and disposition are not predicated with reference to the object of science, but with reference to the soul. Again, it must be considered whether genus and species are predicated after the same manner, according to cases; as, whether they are said to pertain to a certain thing, or are predicated of a certain thing, or are in some other way predicated. For as species, so likewise genus is predicated; as in the double, and the superior genera. For both the double and the multiple are predicated of a certain thing. The like also takes place in science. For both science itself, and the genera of it, namely disposition and habit, are predicated of a certain thing. But here it may be objected that sometimes this is not the case. For the different and the contrary are predicated with reference to a certain thing; but another which is the genus of these, is not predicated with reference to a certain thing, but a thing when it is different from something else, is said to be another thing. Again, it must be considered whether those things which are similarly said to be relatives according to cases, do not similarly reciprocate, as in the double and the multiple.  For each of these is said to be of a certain thing, and according to reciprocation; for both the half, and the least part, are said to be the half, and the least part of a certain thing. The like also takes place in science and opinion; for these are said to be of a certain thing; and similarly reciprocate; since both the object of opinion, and the object of science are predicated with reference to a certain thing. If, therefore, the reciprocation is not similar in a certain thing, it is evident that the one is not the genus of the other. Again, it must be considered whether genus and species are not predicated with reference to an equal number of things. For each of these appears to be predicated similarly, end of the same number of things; as in a gift and giving. For a gift is said to be the gift of a certain person, and to a certain person; and giving is said to be the giving of a certain person, and to a certain person. But giving is the genus of gift; for a gift is a giving not to be returned. In some things, however, it does not happen that there is a predication with reference to an equal number. For the double is the double of a certain thing; but that which exceeds, and that which is greater, are predicated of, and with reference to a certain thing. For everything which exceeds, and everything which is greater, exceeds with respect to a certain thing, and is the excess of a certain thing. Hence the things which have been mentioned are not the genera of the double, since they are not predicated with reference to an equal number of things in species. Or it is not universally true, that genus and species are predicated with reference to an equal number of things. It is likewise requisite to see whether the opposite is the genus of the opposite; as, whether if the multiple is the genus of the double, the least part, or the submultiple, is also the genus of the half. For it is necessary that the opposite should be the genus of the opposite. If, therefore, someone should assert that science is sense, it will also be requisite that the object of science should be sensible. This, however, is not the case. For neither is everything which is an object of science sensible; since some things which are among the number of intelligibles are objects of science. Hence the sensible is not the genus of the object of science. But if it is not, neither is sense the genus of science. Since, however, of things which are predicated with reference to a certain thing, some are necessarily in, or about those, to which they are referred; (as, disposition, habit, and symmetry; for these cannot be in anything else, then those things to which they are referred); but others are not necessarily in the things to which they are sometimes referred, and yet maybe in them; (as, if the soul is an object of science; for nothing hinders but that the soul may have a scientific knowledge of itself, and yet it is not necessary, since it is possible that this very scientific knowledge may be inherent in something else) and others simply cannot be inherent in those things to which they are referred; (as the contrary cannot be in the contrary, nor science in the object of scientific knowledge, unless the object of scientific knowledge should be the soul, or man) — this being the case, it is requisite to consider whether someone asserts that a thing of this kind, is in a genus which is not of this kind;  as, if he should assert that memory is permanency of science. For all permanency is in and about that which is permanent; so that the permanency of science is in science. Memory, therefore, is in science; since it is the permanency of science. This, however, is not possible; for all memory is in the soul. This place also pertains in common to accident. For it is of no consequence, whether permanency is said to be the genus of memory, or to be accidental to it. For if in any manner whatever, memory is the permanency of science, the same reasoning will be adapted to it.

Aristotle, Topics. Book IV, Chapter 5

Again, if habit should be referred to energy, or energy to habit, a thing of this kind is not genus; as if it should be said that sense is a motion through the body. For sense is a habit; but motion is an energy. In a similar manner also, if it should be said that memory is a habit retentive of opinion. For no memory is a habit, but is rather an energy. Those also err, who arrange habit into consequent power; as, those who say that mildness is a continuance of anger; and that fortitude and justice are a continuance of fear and lucre. For he is said to be courageous and mild who is impassive; but he is continent who suffers, but is not led by passion. Perhaps, therefore, a power of this kind is consequent to both, so that though they suffer, yet they will hot be led by, but will vanquish passion. Yet this is not the essence of a courageous or a mild man, hut not to be at all affected with any thing of this kind. Sometimes, however, that which is in any way consequent, is admitted to be genus; as, that pain is the genus of anger, and opinion of faith. For both these are after a certain manner consequent to the assigned species; but neither of them is a genus. For he who is angry is pained, pain being previously produced in him; since anger is not the cause of pain, but pain is the cause of anger. Hence simply anger is not pain. Hence too neither is faith opinion. For it is possible to have an opinion of, without believing in a thing. This, however, would not be possible, if faith is a species of opinion. For it is impossible that any thing should remain the same, if it is entirely changed from species; as neither is it possible that the same animal can at one time be a man, and at another time not. But if some one should say that he who opines, also necessarily believes, opinion and faith will be predicated of the same number of things. Hence, neither thus will it be a genus; for it is necessary that genus should be predicated to a greater extent. It is likewise requisite to see whether both are naturally adapted to be in the same thing. For in that in which species is, genus also is contained; as, in that in which whiteness is, in that also colour is; and in that in which grammar is, science also is. If, therefore, some one should say that shame is fear, or that anger is pain, it will not happen that genus and species are in the same thing. For shame is in the reasoning part of the soul; but fear is in the irascible part. And pain, indeed, is in the desiderative part, for in this pleasure also resides; but anger is in the irascible part. Hence, the things assigned are not genera, since they are not naturally adapted to be in the same subject with species. In a similar manner also, if friendship is in the desiderative part, it will not be a certain will. For all will is in the reasoning part. But this place is useful for the purpose of investigating accident. For accident, and that to which it is an accident are in the same thing; so that unless they should be seen to be in the same thing, it is evident that they are not accidents. Again, it must be considered, whether species participates of that which is said to be genus partially; for genus does not appear to be partially participated. Thus man is not partially an animal, nor is grammar partially a science. The like also takes place in other things. It is requisite, therefore, to consider whether genus in certain things is partially participated; such as, if animal is said to be that which is sensible or visible. For animal is partially sensible and visible; since according to body it is sensible and visible, but not according to soul. Hence the visible and the sensible will not be the genera of animal. Sometimes also through ignorance, the whole is referred to apart; as when it is said that animal is animated body. The part, however, is by no means predicated of the whole; so that body will not be the genus of animal, since it is a part. It is likewise requisite to see whether any thing which is to be blamed or avoided is referred to power, or to the possible; as, if it should be said that a sophist is one who is able to acquire wealth from apparent wisdom; or that a calumniator is one who is able to calumniate, and to make enemies of his friends; or that a thief is one who is able secretly to steal the property of others. For no one of the above-mentioned characters, is said to be such a character, in consequence of being able to act in this manner. For both God and a worthy man are able to perform base actions, yet they are not base characters; since all depraved characters are denominated according to deliberate choice. Again, all powers are among the number of things eligible; for the powers of the depraved are eligible. Hence we say, that both God and a worthy man possess them; for we say that they have the ability of performing base actions. Hence power will not be the genus of any thing blameable; for otherwise it would happen that something blameable would be eligible; since there will be a certain power which is blameable. It must also be considered whether some one of those things which are of themselves honourable or eligible, is referred to power, or to the possible, or to the effective. For all power, and every thing which is possible, or effective, is eligible on account of something else. Or it must be considered whether some one of those things which are in two or many genera, is reduced to one genus. For it is not possible to reduce some things to one genus; as, an impostor, and a calumniator. For neither he who previously chooses, indeed, but is incapable of effecting; nor he who is able to effect, but does not previously choose, is a calumniator, or an impostor; but he who possesses both these. Hence, these two characters must not be placed in one genus, but in both genera. Farther still, sometimes vice versa, genus is assigned as difference, and difference as genus; as, those who say that astonishment is an excess of admiration; and that faith is vehemence of opinion. For neither excess nor vehemence is genus, but difference. For astonishment appears to be excessive admiration; and faith vehement opinion. Hence admiration and opinion are genera; but excess and vehemence are differences. Again, if some one should assign excess and vehemence as genera, things inanimate will have faith, and be astonished. For the vehemence and excess of each thing is present with that, of which it is the vehemence and excess. If, therefore, astonishment is an excess of admiration, astonishment will be present with admiration; so that admiration will be astonished. In a similar manner also, faith will be present with opinion, if it is vehemence of opinion; so that opinion will believe, or possess faith. Again, it will happen to him who thus assigns genus, that he will call vehemence, vehement, and excess, exceeding. For there is a certain vehement faith. If, therefore, faith is vehemence, vehemence will be vehement. In a similar manner also, a certain astonishment is exceeding. If, therefore, astonishment is excess, excess will be exceeding. Neither, however, of these appears to be true; as, neither is science the object of science, nor motion that which is moved. Sometimes also an error arises from placing passion as in genus in that which suffers; as happens to those who say that immortality is perpetual life. For immortality appears to be a certain passion or symptom of life. But that this is true, will become evident, if it is admitted that some one may from being mortal become immortal. For no one would say that he receives another life, but that a certain passion or symptom accedes to his life. Hence life is not the genus of immortality. Farther still, an error also is produced, if that of which there is a passion is said to. be the genus of the passion; as, that wind is air in motion. For wind is rather the motion of air; since the same air remains both when it is moved, and when it abides. Hence, in short, wind is not air; for if it were, there would be wind when the air is not moved, since the same air which was wind remains. The like will also take place in other things of this kind. If, therefore, it should be requisite to grant that wind is air in motion, yet a thing of this kind is not to be admitted in all things; i.e., it must not be admitted in those things of which the proposed genus is not truly predicated, but in those only in which it is truly predicated. For in some things, it does not appear to be truly asserted; as, in snow and clay. For they say that snow is congealed water; and that clay is earth mingled with moisture. But neither is clay earth, nor snow water. Hence, neither of the assigned genera will be a genus. For it is necessary that genus should always be truly predicated of species. In a similar manner, neither is wine putrified water as Empedocles says it is,

The water putrified in wood;

For, in short, wine is not water.

Aristotle, Topics. Book IV, Chapter 6

Again, it must be considered whether, in short, the thing proposed is the genus of nothing; for it is evident that if it is not the genus of any thing, neither will it be the genus of the thing proposed. But this must be considered from the participants of the assigned genus, not at all differing in species. Thus, white things do not all differ in species from each other. But of every genus, the species are different; so that whiteness will not be the genus of any thing. Again, it must be considered whether that which is consequent to all things is said to be genus or difference. For many things are consequent to all things. Thus, being and the one are among the number of things which are consequent to all things. If, therefore, being is assigned as a genus, it is evident that it will be the genus of all things, since it is predicated of them. For genus is not predicated of any thing else than of species. Hence the one also will be a species of being. It happens, therefore, that of all things of which genus is predicated, species also will be predicated; since being and the one are simply predicated of all things, though it is requisite that species should be predicated to a less extent than genus. But if it should be said that that which is consequent to all things is difference, it is evident that difference will be predicated of as many or of a greater number of things than genus. For if genus also is among the number of things which are consequent to all things, it will be predicated to the same extent; but if genus is not consequent to all things, difference will be predicated to a greater extent than genus. Farther still, it must be considered whether the assigned genus is said to be in the subject species, as whiteness in snow; so that it is evident that it will not be a genus; for genus is alone predicated of the subject species. It is also requisite to consider whether genus and species are not synonymous; for genus is predicated synonymously of all species. Again, an error also is produced when there is a contrary to genus and to species, and the better of the contrary (species) is referred to the worse genus; for it will happen that the remainder will be in the remainder, since contraries are in contrary genera. Hence the better (species) will be in the worse (genus). It appears, however, that the genus of that which is better is also better. An error likewise is produced if, when the same thing subsists similarly with respect to both, it is referred to the worse and not to the better genus; as if it should be said that the soul is motion or that which is moved. For the soul appears equally to possess the power of stopping and moving. Hence, if permanency is better than motion, it is necessary to refer it to this genus. Again, he who subverts may argue from the more and the less; if the genus receives the more, but the species does not receive it, neither itself nor that which is denominated according to it. Thus, if virtue receives the more, justice also and a just man receive it; for one just man is said to be more just than another. If, therefore, the assigned genus receives the more, but the species does not receive it, neither itself nor that which is denominated according to it, the thing assigned will not be a genus. Again, if that which seems to be more or similarly is not a genus, it is evident that neither is the thing assigned a genus. But this place is useful in things of that kind especially in which those things appear to be many that are predicated of species in answer to the question of what a thing is, and when it is not defined, and we are unable to say what the genus of them is. Thus of anger, both pain and the opinion of contempt appear to be predicated in answer to the question of what a thing is; for he who is angry is pained and thinks that he is despised. There is also the same consideration in species if it is compared with something else. For if the more, or that which similarly appears to be in the assigned genus, is not in genus, it is evident that neither in short is the assigned species in genus. By him, therefore, who subverts, this place must be thus used. But by him who confirms, this place is not useful if the assigned genus and species receive the more; for nothing hinders when both receive the more, but that the one is not the genus of the other. For the white and the beautiful receive the more, and neither of them is the genus of the other. The comparison, however, of genera and species with each other is useful. Thus, if this thing and that are similarly genera, if one of them is a genus, the other of them is also. In a similar manner, if that which is less is a genus, that is also which is more. Thus, if power more than virtue is the genus of continence, but virtue is a genus, power is likewise. The same things also are adapted to be said of species. For if this thing and that are similarly species of the proposed genus; if the one is a species, the other is also; and if that which appears to be less is a species, that likewise is which is more. Farther still, for the purpose of confirming, it must be considered whether genus in those things in which it is assigned is predicated in answer to the question of what a thing is, when the assigned species is not one, but there are many and different species; for it is evident that it will be a genus. But if the assigned species is one, it must be considered whether the genus is also predicated of other species in answer to the question of what a thing is. For again, it will happen that the same thing will be predicated of things which are many and different, and will be acknowledged to be a genus. Since, however, it appears to some that difference also is predicated of species in the question of what a thing is, genus must be separated from difference, by using the before-mentioned elements. In the first place, indeed, because genus is predicated to a greater extent than difference. In the next place, because in answer to the question of what a thing is, genus is more adapted than difference. For he who says that man is an animal manifests in a greater degree what man is than he who says he is pedestrious. And because difference always signifies the quality of genus; but genus does not signify the quality of difference. For he who says that man is pedestrious says what kind of an animal he is; but he who says that he is an animal does not say what the kind is of the pedestrious. Difference, therefore, must thus be separated from genus. Since, however, that which is musical, so far as it is musical, appears to be scientific; music also is a certain science. And if that which walks is moved by walking, walking is a certain motion. After this manner, therefore, someone must consider in what genus he wishes to place a certain thing. Thus, if he wishes to show that science is faith, it must be considered whether he who possesses scientific knowledge, so far as he possesses this knowledge, believes; for thus it will be manifest that science is a certain faith. The same method must be adopted in other things of this kind. Farther still, since it is difficult to separate from genus that which is always consequent to a certain thing, and does not reciprocate, and to show that it is not genus; if this thing is consequent to every individual of that, but that is not consequent to every individual of this, as quiet is consequent to tranquillity, and divisibility to number; but not the contrary; for not everything divisible is number, nor is all quiet tranquillity, he who disputes should use this place as if genus were that which is always consequent, when the other does not reciprocate. If, however, another proposes this argument, it must not be admitted in all things. But the objection to it is that non-being is consequent to everything which is generated, for that which is generated is not, and does not reciprocate (for not everything which is not is generated); but at the same time, non-being is not the genus of that which is generated. For simply, there are no species of non-being. Concerning genus, therefore, the discussion must be made after the manner we have mentioned.

Aristotle, Topics. Book V, Chapter 1

Book V, Chapter 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09

Whether, however, that which is asserted is peculiar or is not peculiar must be considered through the following places. But peculiarity is assigned either per se and always, or with relation to something else and sometimes; as the peculiarity of man per se is that he is an animal naturally mild. And peculiarity with relation to something else is such as that of the soul with reference to the body; because the former commands, but the latter obeys. Peculiarity is likewise assigned always, as the peculiarity of God is to be an immortal animal. And it is assigned sometimes, as it is the peculiarity of a certain person to walk in the gymnasium. But the peculiarity which is assigned with reference to something else either produces two or four problems. For if it is affirmed of one thing and denied of another, two problems only are produced; as the peculiarity of man with respect to horse is that he is a biped. For that man is not a biped may be argued by someone, and also that a horse is a biped; but in both ways, peculiarity may be subverted. But if each is affirmed of each and denied of each, there will be four problems; as the peculiarity of man with reference to horse is that the former is a biped and the latter a quadruped. For that man is not a biped, and that he is naturally a quadruped may be argued; and also that a horse is a biped, and not a quadruped. In whatever manner, therefore, this is shown, the proposed problem is subverted. That, however, is peculiarity per se, which is attributed to all things and separates from everything; as of man, the peculiarity per se is to be a mortal animal and the recipient of science. But peculiarity with reference to another is that which does not separate from everything, but from a certain definite thing. Thus, the peculiarity of virtue with respect to science is that the one is naturally adapted to be produced in many things, but the other in the reasoning part alone, and in those who possess the reasoning part. And the peculiarity always is, which is verified at all times, and never fails to be true. Thus it is always the peculiarity of an animal to be composed of soul and body. But the peculiarity exists sometimes, which is verified at a certain time and does not always follow from necessity. Thus, it is the peculiarity of a certain man to walk in the forum. To assign, however, peculiarity with reference to something else is to assert that difference either is in all things and always, or is for the most part and in most things. Thus, the peculiarity of man with respect to horse, in all men, and always is being a biped; for every man is a biped, and is always a biped; but no horse is ever a biped. But the difference which is for the most part and in most things is such as that of the rational part, the peculiarity of which is to govern, with relation to the desiderative and irrational part; because the one commands, but the other obeys. For the rational part does not always govern, but sometimes is governed; and the desiderative and irascible parts do not always obey, but sometimes command when the soul of man is depraved. But of peculiarities, those are especially logical which are per se and always, and which subsist with reference to something else. For the peculiarity which exists with reference to another thing produces many problems, as we have before observed; since either two or four problems are necessarily produced. Many arguments, therefore, pertaining to these things are founded. But it is possible to argue about that which is per se and always with reference to many things, and to observe it with reference to many times. That which is per se, indeed, may be the subject of argument with reference to many things; for it is necessary that peculiarity should be present with a subject with reference to everything that exists; so that if it is not separated from all things, it will not be properly assigned as peculiarity. But that which is always said to be peculiar may be observed with reference to many times; and whether it is not present, or was not present, or will not be present, it will not be peculiarity. That, however, which is at a certain time peculiar we cannot perceive in any other than what is called the present time. Hence there are not many arguments pertaining to it. But that is a logical problem, with reference to which numerous and beautiful arguments are framed. That, therefore, which is said to be peculiarity with reference to something else must be considered from the places concerning accident; viz., whether it happens to one thing, but not to another. But those peculiarities which are per se and always must be surveyed through what follows.

Aristotle, Topics. Book V, Chapter 2

In the first place, therefore, it must be considered whether peculiarity is well or not well explained. Of the question whether it is well or ill explained, one consideration is if peculiarity is posited not through things which are more known, or through things which are more known; peculiarity being subverted if posited not through things which are more known, but being confirmed if posited through such as are more known. Of being posited, however, through the former, one mode is if, in short, the peculiarity which someone assigns is more unknown than that of which it is said to be the peculiarity. For the peculiarity will not in this case be well posited, since we employ peculiarity for the sake of knowledge. For we introduce peculiarity and definitions for the sake of learning. Hence, peculiarity must be explained through things which are more known; for thus we shall be more sufficiently able to understand it. Thus, for instance, since he who says that the peculiarity of fire is to be most similar to the soul uses the soul, which is more unknown than fire (for we know what fire is better than what the soul is), to be most similar to the soul will not be well posited as the peculiarity of fire. Another mode is if it is not more known that this thing is present with that. For it is not only necessary that peculiarity should be more known than a thing, but also that it should be more known that it is present with this thing; since he who is ignorant whether it is present with this thing will not know whether it is present with this thing alone. Hence, whichever of these should happen to be the case, the peculiarity will become obscure. Thus, since he who asserts the peculiarity of fire to be that in which the soul is primarily naturally adapted to subsist uses that which is more unknown than fire, i.e., if the soul is inherent in this and if it is primarily inherent in this; hence that in which the soul is primarily naturally adapted to subsist will not be well posited as the peculiarity of fire. Peculiarity, however, is confirmed if it is posited through things which are more known and if through things which are more known according to each mode. For according to this, peculiarity will be well posited. Of the places which are able to confirm anything rightly, some show that it is properly posited according to this only, but others simply show it. Thus, since he who says that the peculiarity of animal is to possess sense assigns peculiarity according to each mode through things more known, and in a manner more known, according to this it is well assigned that the peculiarity of animal is to possess sense. In the next place, peculiarity is subverted if someone of the names which are assigned in the peculiarity is multifariously predicated, or if, in short, the sentence signifies many things. For the peculiarity will not be well posited. Thus, since to perceive signifies many things, one of which is to possess sense, but another to use sense; the peculiarity of animal will not be well posited as a natural aptitude to sensation. Hence, neither must a name be used which has a multifarious signification, nor a definition for the purpose of signifying peculiarity; because that which is multifariously predicated causes that which is asserted to be obscure, he who is about to argue being dubious which he shall adopt of the things that are multifariously predicated. For peculiarity is assigned for the sake of learning. Farther still, it is necessary that a certain elenchus (i.e., syllogism of contradiction) should be employed against those who thus explain peculiarity when someone in a signification in which what is proposed is false forms a syllogism of that which is multifariously predicated. But peculiarity is confirmed if neither any name nor the whole sentence signifies many things; for peculiarity, so far as pertains to this, will be well posited. Thus, since neither body signifies many things, nor that which is most easily moved to the upward place, nor the whole which is composed from these; hence, a body which is most easily moved to the upward place will, according to this, be well posited as the peculiarity of fire. In the next place, peculiarity is subverted indeed if that is predicated in many ways of which the peculiarity is assigned, and it is not defined of which of them the peculiarity is posited; for thus the peculiarity will not be well assigned; but from what causes is not immanifest from what has been said; since it is necessary that the same things should happen. Thus, since to know this thing scientifically signifies many things; for it signifies that this subject possesses science, that this subject uses science, that there is a science of this thing, and to use the science of it, no peculiarity of scientifically knowing this thing will be well assigned unless it is defined of which of them the peculiarity is posited. But peculiarity will be confirmed if that of which the peculiarity is posited is not multifariously predicated but is one and simple; for so far as pertains to this, peculiarity will be well posited. Thus, since man is simply predicated, the peculiarity of man will be well posited to be an animal naturally mild. Again, peculiarity is subverted indeed if the same thing is frequently mentioned in the peculiarity; for this is often done ignorantly, as well in peculiarities as in definitions. But a peculiarity of this kind will not be rightly posited; for the frequency of the repetition disturbs the hearer. Hence the peculiarity necessarily becomes obscured. And besides this, an appearance of loquacity is produced. It happens, however, that the same thing is frequently repeated in two ways. In one way, indeed, when the same thing is frequently denominated; as if someone should assert the peculiarity of fire to be a body the most attenuated of bodies; for he repeats the word body. But in another way, if someone should assume definitions instead of names; as if he should assert the peculiarity of earth to be an essence which the most of all bodies naturally tends to the downward place; and afterwards should assume, instead of the word bodies, such essences. For body and such an essence are one and the same thing. Hence, he will repeat the word essence. Neither of the peculiarities, therefore, will be well posited. But peculiarity is confirmed if no one name is frequently used; for so far as pertains to this, peculiarity will be well assigned. Thus, since he who says that the peculiarity of man is an animal receptive of science does not frequently use the same name, the peculiarity of man, so far as pertains to this, will be well assigned. Farther still, peculiarity will be subverted indeed if a name of such a kind is assigned in the peculiarity as is present with all things. For that will be useless which is not separated from certain things. But that which is asserted in peculiarities ought to separate, in the same manner as the particulars in definitions. The peculiarity, therefore, will not be well posited. Thus, since he who asserts that the peculiarity of science is opinion which cannot be changed by reason, uses a certain thing of this kind in explaining peculiarity, viz., one thing which is present with all things; the peculiarity of science will not be well posited. Peculiarity, however, is confirmed if no common word is used, but that only which separates from a certain thing; for so far as pertains to this peculiarity, it will be well posited. Thus, since he who says that the peculiarity of animal is to have a soul uses no common word so far as pertains to this, the peculiarity of animal will be well posited to be the possession of soul. Again, peculiarity is subverted indeed if many peculiarities are assigned of the same thing without explaining that many are assigned; for peculiarity will not be well posited. For as in definitions it is not necessary that anything more should be added besides the sentence by which essence is unfolded; so neither in peculiarities should anything be adjoined besides the sentence which causes what is asserted to be peculiarity; for a thing of this kind is useless. Thus, since he who says that the peculiarity of fire is to be a body the most attenuated and light assigns many peculiarities; for each is truly asserted of fire alone; the peculiarity of fire will not be well posited as a body the most attenuated and light. But peculiarity is confirmed if not many peculiarities of the same thing are assigned, but one; for so far as pertains to this, peculiarity will be well posited. Thus, since he who says that the peculiarity of moisture is a body which may be brought to assume every shape assigns one peculiarity and not many; so far as pertains to this, the peculiarity of moisture will be well posited.

Aristotle, Topics. Book V, Chapter 3

In the next p1ace, peculiarity will be subverted, if that is used, the peculiarity of which is assigned, or some one of those things which are subject] to it; for peculiarity will not be well posited; since it is assigned for the sake of learning. The same thing, therefore, is similarly unknown with itself. But that which is subject to a certain thing is posterior to it; and, therefore, is not more known. Hence through these things it does not happen that any thing is learnt in a greater degree. Thus, since he who says that the peculiarity of animal is an essence, a species of which is man, uses some one of those things which arc subject to animal, the peculiarity will not be rightly posited. But peculiarity is confirmed, if neither that, the property of which is explained, nor any one of tbose things which are subject to it, is used. For so far as pertains to this, peculiarity will be well posited. Thus, since he who asserts that the peculiarity of animal is that which is composed from soul and body, neither uses animal, nor any one of those things which are subject to it; so far as pertains to this, the peculiarity of animal will be well assigned. After the same manner also it must be considered in other things which do not cause, or which cause a thing to be more known; subverting indeed, if either that which is opposite is used, or in short, that which is simultaneous by nature, or that which is posterior; for thus peculiarity will not be well posited. For that which is opposite is simultaneous by nature; but that which is simultaneous by nature, and that which is posterior; do not make a thing to be more known. Thus, since he who says that the peculiarity of good is, that which is especially opposed to evil, uses that which is opposed to good, the peculiarity of good will not be well assigned. But peculiarity is confirmed, if nothing opposite is used, nor in short, that which is simultaneous by nature, nor that which is posterior; for so far as pertains to this, peculiarity will be well assigned. Thus, since he who asserts that the peculiarity of science is opinion which is in, the highest degree credible, uses neither that which is opposite, nor in short, that which is naturally simultaneous, nor that which is posterior; so far as pertains to this, the peculiarity of science will be well posited. In the next place; peculiarity is subverted indeed, if that peculiarity which is always consequent is not assigned, but that which sometimes is not peculiarity; for thus peculiarity will not be well explained. For neither of that in which we apprehend it is necessarily inherent will the name be verified; nor of that in which it is apprehended not to be inherent, will the name necessarily not the asserted. Hence, the peculiarity will not be well posited. Again, in addition to these things, neither when peculiarity is assigned, will it be evident whether it is inherent; if it is a thing of that kind that it may fail. The peculiarity, therefore, will not be manifest. Thus, since he who asserts that the peculiarity of animal is, sometimes to be moved or stand still, assigns a peculiarity of such a kind, as sometimes is not a peculiarity; the peculiarity will not be well posited. Peculiarity, however, is confirmed, if that which necessarily always is, is assigned as the peculiarity; for so far as pertains to this, it will be well posited. Thus, since he who asserts that the peculiarity of virtue is that which makes its possessor a worthy man, assigns that which is always consequent, as the peculiarity; so far as pertains to this, the peculiarity of virtue will be well assigned. In the next place, peculiarity is subverted, if some one assigning that which is now a peculiarity, does not declare that he assigns that which is now a peculiarity; for the peculiarity will not be well posited. For in the first place, every thing which is contrary to custom, requires explanation; but for the most part, it is usual with all men, to assign as the peculiarity of a thing that which is always consequent. In the second place, it is immanifest, whether he who does not explain, wishes to adduce that which is now peculiarity. A pretext, therefore, of reproof must not be given. Thus, since he who asserts that the peculiarity of a certain man is to sit with a certain man, asserts that which is now a peculiarity, peculiarity will not be well assigned, unless he declares that he speaks of that which is now a peculiarity. But it is confirmed, if some one assigning that which is now peculiarity, declares that he adduces what is now a peculiarity; for so far as pertains to this, peculiarity will be well posited. Thus, since he who says that it is the peculiarity of a certain man to walk now in a certain place, asserts this accompanied with a distinction; peculiarity will be well posited. In the next place, it is subverted if a peculiarity of such a kind is assigned, which is no otherwise known to be inherent than by sense; for the peculiarity will not be well posited. For every thing sensible when it becomes external to sense, is immanifest; since it is not apparent, whether it is yet inherent, because it is only known by sense. But this will be true in those things which do not always follow from necessity. Thus, since he who asserts that it is the peculiarity of the sun to be the most splendid star which is moved above the earth, employs in explaining the peculiarity the words to be moved above the earth, which. is known by sense; the peculiarity of the sun will not be well assigned. For it will be immanifest when the sun sets, whether it is moved above the earth, because sense then fails us. Peculiarity, however, is confirmed, if a peculiarity of such a kind is delivered, as is not manifest to sense; or, which being sensible, is manifestly inherent from necessity. Thus, since he who admits that it is the peculiarity of superficies, to be that which is first coloured, uses indeed something sensible, viz. to be coloured; but a sensible of such a kind as is evidently always inherent; so far as pertains to this, the peculiarity of superficies will be well assigned. Again, peculiarity is subverted, if definition is assigned as peculiarity. For peculiarity will not be well posited; since it ought not to manifest the very nature of a thing. Thus, since he who says that the peculiarity of man is a biped terrestrial animal, and thus assigns as the peculiarity of man, that which signifies his very nature; the peculiarity of man will not be well assigned. But peculiarity is confirmed, if a peculiarity which reciprocates is assigned, but which does not manifest the very nature of a thing;· for so far as pertains to this, peculiarity will be well asisgned. Thus, since he who says that peculiarity of man is an animal naturally mild, assigns a peculiarity which reciprocates, and which does not manifest the very nature of man; so far as pertains to this, the peculiarity of man will be well assigned. Farther still, peculiarity is subverted, if he who assigns it, does not assert what a thing is. For it is necessary, as in definitions, so likewise in peculiarities, that the first genus should be assigned, afterwards that what remains should be added, and that the thing proposed should be separated from other things. Hence the peculiarity which is not after this manner posited, will not be well assigned. Thus, since he who says that the peculiarity of animal is to have a soul, does not assert what an animal is; the peculiarity of animal will not be well assigned. But peculiarity is confirmed if some one when he asserts what that thing is of which he assigns the peculiarity, adjoins what remains; for so far as pertains to this, peculiarity will be well assigned. Thus, since he who asserts that the peculiarity of man is to be an animal receptive of science, by asserting what man is, assigns his peculiarity; so far as pertains to this, the peculiarity of man will be well posited. Whether, therefore, peculiarity is well, or not well assigned, must through these things be considered.

Aristotle, Topics. Book V, Chapter 4

Whether, however, what is assigned, is, in short, peculiarity, or is not peculiarity, may be surveyed from these places. For those places which simply confirm that peculiarity is well posited, will be the same as those which produce peculiarity; and, therefore, together with them will be explained. In the first place then, in confirmation, it is requisite to direct our attention to each particular, the peculiarity of which is assigned; as, whether it is present with no individual, or so far as pertains to this is not verified, or whether each of them is not peculiarity, so far as pertains to that, the peculiarity of which is assigned. For thus the peculiarity will not be that which was posited to be peculiarity. Thus, since it is not truly asserted of a geometrician, that he cannot be deceived by reasoning; for a geometrician is decieved, when he makes a false description; this will not be the peculiarity of the man of science, not to be deceived by reasoning. But peculiarity is confirmed, if it is verified of every thing, and so far as pertains to this is verified; for that which is posited not to be peculiarity, will be peculiarity. Thus, since animal is receptive of science, it is verified of every man, and so far as he is man; and, therefore, the peculiarity of man will be, that he is an animal receptive of science. This place, however, pertains to subversion, if a sentence is not verified of that of which the name is verified, and if of that of which a sentence is verified the name is not verified. And it pertains to confirmation, if that of which the name, a sentence also is verified, and if that of which a sentence, the name also is predicated. In the next place, peculiarity is, indeed, subverted; if of that of which a sentence is verified, the name also is not verified, and if a sentence is not verified of that of which the name is verified; for that which is posited to be peculiarity will not be peculiarity. Thus, since an animal receptive of science is verified of a God, but man is not predicated of a God; an animal receptive of science, will not be the peculiarity of man. But peculiarity is confirmed, if of that of which a sentence, the name also is predicated; and if of that of which the name, a sentence also is predicated. For that will be the peculiarity, which was posited not to be the peculiarity. Thus, since animal is verified of that of which the possession of soul is verified; and the possession of soul, of that of which animal is verified; the possession of soul will be the peculiarity of animal. Again, peculiarity is subverted, indeed, if the subject is assigned as the peculiarity of that which is said to be in the subject; for that which was posited to be peculiarity will not be peculiarity. Thus, since he who asserts that the peculiarity of a body of the most attenuated parts, is fire, assigns the subject as the peculiarity of that which is predicated; fire will not be the peculiarity of a body of the most attenuated parts. But on this account, the subject will not be the peculiarity of that which is said to be in the subject, because the same thing will be the peculiarity of many things specifically different. For many tbings differing in species are present with the  same thing, and which are predicated of it alone, the peculiarity of all which will be the subject, if peculiarity is thus posited. Peculiarity, however, is confirmed, if that which is in the subject, is assigned as the peculiarity of the subject. For that which is posited not to be the peculiarity will be the peculiarity, if it is predicated of that alone, of which it is said to be the peculiarity. Thus, since he who says that the peculiarity of earth is a body the most specifically heavy, assigns the peculiarity of the subject, which is predicated of that thing alone, and is predicated as peculiarity; the peculiarity of earth will be well posited. In the next place, peculiarity is subverted, if it is assigned according to participation; for that which was posited to be, will not be peculiarity. For that which is present according to participation, pertains to the very nature of a thing; but a thing of this kind will be a certain difference which is predicated of a certain species. Thus, since he who says that the peculiarity of man is a pedestrious biped, assigns the peculiaritv according to participation; the peculiarity of man will not be a pedestrious biped. But peculiarity is confirmed, if it is not assigned according to participation, nor manifests the very nature of a thing, when the thing reciprocates with it; for that which is not posited to be, will be peculiarity. Thus, since he who asserts that the peculiarity of animal is naturally to possess the faculty of sensation, neither assigns peculiarity according to participation, nor manifests the very nature of a thing, the thing at the same time reciprocating with it, naturally to possess the faculty of sensation, will be the peculiarity of animal. In the next place, peculiarity is subverted, if it is not possible that it can be at one and the same time inherent, but is either posterior or prior to that of which it is the name. For that which is posited to be peculiarity, will not be peculiarity, either never, or not always. Thus, since it is possible that to walk through the forum may be present with a certain animal, prior and posterior to its being present with a man; to walk through the forum will not be the peculiarity of man, either never, or not always. But peculiarity is confirmed, if at one and the same time it always exists from necessity, neither being definition nor difference; for that which is posited not to be, will be peculiarity. Thus, since animal, the recipient of science, and man, always necessarily exist at one and the same time, neither being definition, nor differcnce; animal, the recipient of science, will be the peculiarity of man. In the next place, peculiarity is subverted, indeed, if the same thing is not the peculiarity of the same things, so far as they are the same; for that will not be, which is posited to be the peculiarity. Thus, since to appear to be good to certain persons, is not the peculiarity of that which is the object of pursuit; to appear to be good to certain persons, will not be the peculiarity of the eligible. For that which is an object of pursuit and the eligible are the same. But peculiarity is confirmed, if the same thing is the peculiarity of the same thing, so far as it is the same thing; for that which is posited not to be, will be, the peculiarity. Thus, since to have a tripartite soul, is said to be the peculiarity of man, so far as he is man; to have a tripartite soul will also be the peculiarity of mortal, so far as mortal. This place is likewise useful in accident. For it is necessary that the same things should be present or should not be present with the same things, so far as they are the same. In the next place, peculiarity is subverted, if that which is the same in species, is not always the peculiarity of things which are the same in species; for that which is posited to be peculiarity will not be the peculiarity of the thing proposed. Thus, since man and horse are the same in species; but it is not always the peculiarity of a horse to stand from himself; neither will it always be the peculiarity of a man to be moved by himself; since for a thing to be moved, and to stand from itself, are the same in species; for they happen to each of these, so far as each is an animal. But peculiarity is confirmed, if the same thing in species, is always the peculiarity of things specifically the same; for that which is posited not to be, will be, the peculiarity. Thus, since the peculiarity of man is to be a pedestrious biped; of bird also the peculiarity will be, to be a winged biped. For each of these is the same in species, so far as some of these are as species under the same genus, viz. under animal; but others, are as the differences of genus, viz. of animal. This place, however, is false, when one of the things which have been mentioned is alone present with one species, but the other is present with many, as pedestrious quadruped. But since same and different are multifariously predicated, it is difficult when these are sophistically assumed, to assign the peculiarity of one certain thing alone. For that which is present with a certain thing to which a certain thing happens, will also be present with the accident, assumed together with that to which it is an accident. Thus, that which is present with man, will also be present with a white man, if man is white. And that which is present with a white man, is also present with man. Some one, however, may calumniate peculiarities of this kind, if he makes one subject to subsist per se, and another, with accident; as, if he should say that man is one thing, and a white man another. And likewise, if he makes one thing to be habit, and that which is denominated according to habit. For that which is present with habit, will also be present with that which is denominated according to habit. That likewise which is present with that which is denominated according to habit, will also be present with habit. Thus, since he who possesses scientific knowledge, is said to be disposed according to science, the peculiarity of science will not be, the being unchanged in opinion by reason; for he who possesses scientific knowledge, would retain his opinion without being changed by reason. But in confirmation, it must be said, that simply that to which a thing happens, and accident, assumed together with that to which it happens, are not different; but that they are said to be different, because their essence is different. For it is not the same thing for man to be man, and for a white man to be a white man. Farther still, cases must be surveyed, and it must be said, that neither does that possess scientific knowledge, which cannot be induced by reason to change its opinion, but he who is unchanged in his opinion by reason, nor is science that which cannot by reason be induced to change its opinion, but it is the being unchanged in opinion in the feminine gender by reason. For he who objects in every wa_ must in every way be opposed.

Aristotle, Topics. Book V, Chapter 5

In the next place, peculiarity is subverted, if he who wishes to assign that which is naturally inherent, inserts it after that manner in his discourse, as to signify that which is always inherent. For he will appear to have subverted that which was posited to be the peculiarity. Thus, since he who says that the peculiarity of man is to be a biped, wishes, indeed, to assign that which is naturally inherent, but signifies, in the words of this sentence, that which is always inherent, biped will not be the peculiarity of man; for not every man has two feet. But peculiarity is confirmed, if he wishes to assign the peculiarity which is naturally inherent, and signifies it after this manner in words; for so far as pertains this, it will not be subverted. Thus, since he who assigns the peculiarity of man to be, an animal receptive of science, wishes also to signify in words the peculiarity which is naturally inherent, it will not, so far as pertains to this, be subverted, as if it were not the peculiarity of man, to be an animal receptive of science. Again, with respect to such things as are said to be first through something else, or as that which is itself first, (i.e. per se) of such as these, it is difficult to assign the peculiarity. For if you assign the peculiarity of that which is through something else, it will also be verified of that which is first. But if you assign the peculiarity of that which is first, it will also be predicated of that which subsists through, or according to something else. Thus, if some one should assert that the peculiarity of superficies is to be coloured, to be coloured will also be verified of body; but if of body, it will also be predicated of superficies. Hence of that of which a sentence is verified, a name is not also verified. It happens, however, in some peculiarities, that an error is for the most part produced, because it is not defined how, and of what things, the peculiarity is posited. For all men endeavour to assign peculiarity, either as that which is naturally inherent, as of man to be a biped; or as that which is merely inherent, as of a certain man to have four fingers; or as in species, as of fire, that which is most attenuated; or simply, as of an animal, to live; or through another, as of the soul, to be wise; or as that which is first, as of the reasoning power to possess prudence; or as to have, as of the man of science, not to be changed in his opinion by reason; (for not to be moved to a change in opinion by reason, is nothing else than to have something, either bccause it is had or possessed, as, of science, the being unchanged by reason, or because it is participated, as, sensation by animal; for something else also has sensation, as, for instance, man, but he perceives because he is a participant of animal) or in consequence of participating, as, of a certain animal, to live. He, therefore, who does not add the word naturally, errs; because it is possible that what is naturally inherent, may not be inherent in that to which it is natural to be inherent; as in a man, to have two feet. But he who does not explain that he assigns what is inherent errs, because a thing will some time or other not be such, as it now is; as, for a man to have four fingers.  He also errs who does not evince that he assigns peculiarity as that which is first, or as that which is through something else; because name is not verified of that of which definition is verified; as to be coloured, whether it is assigned as the peculiarity of superficies, or of body. But he who does not previously assert that he assigns peculiarity, either because a thing has, or is had errs because that which is assigned will not be pcculiarity. For if he should assign peculiarity to the thing which is had, it will also be inherent in that which has, or possesses it; but if he assigns it to that which has, it will also be inherent in that which is had; as, the being unchanged in opinion by reason, whether it is posited as the peculiarity of science, or of the man of science. He, however, who does not previously signify that he assigns peculiarity because a thing participates, or is participated errs, because peculiarity will also be present with certain other things. For if he should assign peculiarity because it is participated, it will also be present with those things which participate; but if because it participates, it will also be present with those things which are participated; as, if to live should be posited to be the peculiarity of a certain animal, or of animal. He likewise errs, who does not clearly explain, that he assigns peculiarity in species; because it will be present with one thing alone of those things which are arranged under it, of which the peculiarity is, posited. For that which exists according to excess, is present with one thing alone; as, if the peculiarity of fire should be assigned to be that which is most light. Sometimes also, he who adds the words in species, errs. For it will be requisite that there should be one species of those things which are said to receive peculiarity when the words in species are added. This, however, in certain things does not happen, as neither does it happen in fire. For there is not one species of fire; since, a burning coal, flame, and light, each of which is fire, are specifically different. Hence, it is not necessary, that when the words in species are added, there should be another species of that which is said l to receive peculiarity; because the adduced peculiarity is with some things more, and with others, less present; as, that which consists of the most attenuated parts, if it is assigned as the peculiarity of fire. For light consists of more attenuated parts than a burning coal, and flame. This, however, ought not to be the case, unless the name is more predicated of that of which the definition is more verified; for otherwise, it will not be true, that of that of which the definition is more predicated, the name also is more predicated. Again, in addition to what has been said, it will happen that the same thing is the peculiarity of that which is simply, and of that which is especially in a thing that is simply such; as that which consists of the most attenuated parts, if it is considered in fire. For this very thing will be simply the peculiarity, both of light and fire; since light consisteth of the most attenuated parts. We must argue, therefore, if another person should thus assign peculiarity. But he who explains peculiarity must not yield to this objection; but immediately, when he assigns peculiarity, define the manner in which he assigns it. In the next place, peculiarity is subverted, if a thing is posited as the peculiarity of itself. For that which is posited to be, will not be peculiarity. For every thing which is the same with a thing, manifests the essence of that thing; but that which manifests essence, is not peculiarity, but definition. Thus, since be who says that the becoming is the peculiarity of the beautiful in conduct, assigns a thing to be the peculiarity of itself; (for the beautiful in conduct, and the becoming are the same) the becoming will not be the peculiarity of the beautiful in conduct. But peculiarity is confirmed, if the same thing is not assigned to be the peculiarity of itself, but that is posited which reciprocates. For that which is posited not to be, will be the peculiarity. Thus, since he who asserts that the peculiarity of animal is an animated essence, does not introduce the same thing as the peculiarity of itself, but assigns that which reciprocates; an animated essence will be the peculiarity of animal. In the next place, these things must be considered, in things which consists of similar parts. By him who subverts, indeed, it must be considered whether the peculiarity of the whole is not verified of the part, or whether the peculiarity of the part is not predicated of the whole. For that which is posited to be, will not be, peculiarity. This, however, happens to take place in certain things. For some one may assign peculiarity in things of similar parts, sometimes looking to the whole, and sometimes directing his attention to what is said to be according to a part; but neither will be rightly assigned. Thus, for instance, in the whole of a thing: since he who says that the peculiarity of the sea is, an abundance of salt water, introduces the peculiarity of a certain thing which consists of similar parts; but assigns a thing of such a kind as is not verified of a part; (for a certain sea does not abound with salt water) the peculiarity of the sea will not be, an abundance of salt water. But let the following be an instance in the part of a thing: Since he who asserts that the peculiarity of air is the respirable, asserts the peculiarity of a certain thing which consists of similar parts, but assigns a thing of such a kind, as is verified of a certain air, but not of all air; (for all air is not respirable) the peculiarity of air will not be the respirable. By him who confirms, however, it must be considered whether of each of the things consisting of similar parts, that is verified, which is the peculiarity of them according to the whole. For that which is posited not to be will be peculiarity. Thus, since a tendency downward naturally is verified of all earth, and this is also the peculiarity of a certain portion of earth according to the whole, (for it is according to the earth, and because it is earth) the peculiarity of earth will be a tendency downward according to nature.

Aristotle, Topics. Book V, Chapter 6

In the next place, peculiarity must be considered from opposites, and first, from contraries. And by him who subverts, indeed, it must be considered whether the contrary is not the peculiarity of the contrary; for one contrary will not be the peculiarity of another contrary. Thus, since injustice, indeed, is contrary to justice, but that which is worst is contrary to that which is best, and that which is best is not the peculiarity of justice; that which is worst will not be the peculiarity of injustice. But by him who confirms, it rnust be considered whether the contrary is the peculiarity of the contrary; for one contrary will be the peculiarity of another contrary. Thus, since evil is contrary to good, and that which is to be avoided, to that which is eligible, but the peculiarity of the good is the eligible; that which is to be avoided will be the peculiarity of evil. The second place is from things which are relatives. And peculiarity is subverted, indeed, if one relative is not the peculiarity of another; for this relative will not be the peculiarity of that relative. Thus, since the double is referred to the half, and the exceeding to that which is exceeded, but the exceeding is not the peculiarity of the double; that which is exceeded will not be the peculiarity of the half. But peculiarity is confirmed, if one relative is the peculiarity of another; for then this relative will be the peculiarity of that. Thus, since the double is referred to the half, but two is referred to one, and the peculiarity of the double is to be as two to one; the peculiarity of the half will be, to be as one to two. In the third place, peculiarity is subverted indeed, if that which is predicated according to habit, is not the peculiarity of habit; for neither will that which is predicated according to privation be the peculiarity of privation. And if that which is predicated according to privation is not the peculiarity of privation; neither will that which is predicated according to habit, be the peculiarity of habit. Thus, since a privation of sense, is not said to be the peculiarity of deafness, (for this also is common to other things) neither will sensation be the peculiarity of hearing. But peculiarity is confirmed, if that which is predicated according to habit, is the peculiarity of habit; for then, that also which is predicated according to privation, will be the peculiarity of privation. And if that which is predicated according to privation is not the peculiarity of privation; that also which is predicated according to habit, will be the peculiarity of habit. Thus, since it is the peculiarity of sight to behold, in consequence of possessing sight; it will be the peculiarity of blindness not to behold, in consequence of not possessing sight though there is a natural adaptation to the possession of it. In the next place, arguments must be formed from affirmations and negations, and first from the things themselves which are predicated. But this place is alone useful to him who subverts. Thus, if affirmation, or that which is predicated according to affirmation, is the peculiarity of a thing; neither negation, nor that which is predicated according to negation, will be the peculiarity of it. And if negation, or that which is predicated according to negation, is the peculiarity of a thing; neither affirmation, nor that which is predicated according to affirmation, will be the peculiarity of it. Thus, since the animated is the peculiarity of animal; that which is not animated, will not be the peculiarity of animal. The second place is from things which are predicated, or which are not predicated, and of which they are predicated, or not predicated. And peculiarity is, indeed, subverted, if affirmation is not the peculiarity of affirmation; for neither will negation be the peculiarity of negation. And if negation is not the peculiarity of negation, neither will affirmation be the peculiarity of affirmation. Thus, since animal is not the peculiarity of man, neither will that which is not animal be the peculiarity of that which is not man. And if that which is not animal, does not appear to be the peculiarity of that which is not man, neither will animal be the peculiarity of man. But it is confirmed as follows. If affirmation is the peculiarity of affirmation, negation will also be the peculiarity of negation. But if negation is the peculiarity of negation, affirmation will also be the peculiarity of affirmation. Thus, since not to live is the peculiarity of that which is not an animal; to live, will be the peculiarity of animal. And, if to live, appears to be the peculiarity of animal, not to live will appear to be the peculiarity of that which is not an animal. The third place is from subjects themselves. And peculiarity is subverted indeed, if the assigned peculiarity, is the peculiarity of affirmation; for it will not also be the peculiarity of negation. But if that which is assigned is the peculiarity of negation, it will not be the peculiarity of affirmation. Thus, since the animated is the peculiarity of animal; the animated will not be the peculiarity of that which is not an animal. But peculiarity is confirmed, if that which is assigned is not the peculiarity of affirmation; for then it will be the peculiarity of negation. This place, however, is false. For affimation is not the peculiarity of negation, nor negation of affirmation. For affirmation, indeed, is not at all present with negation; but negation is present, indeed, with affirmation; yet it is not present as peculiarity. In the next place, from things which receive an opposite division, peculiarity is subverted, if no one of the things which receive an opposite division, is the peculiarity of no one of the remaining particulars which receive an opposite division. For neither will that which is posited be the peculiarity of that of which it is posited to be the peculiarity. Thus, since sensible animal is not the peculiarity of any mortal animal; intelligible animal will not be the peculiarity of God. But peculiarity is confirmed, if any one of the remaining particulars which receive an opposite division, is the assumed peculiarity, when some one of the things which are oppositely divided, is the peculiarity of each of the things which receive an opposite division. For that which remains will be the peculiarity of that which remains, of which it is posited not to be the peculiarity. Thus, since it is the peculiarity of prudence to be the virtue of the reasoning part, per se, and naturally, and this is the case with the other virtues, each of them being thus assumed; the peculiarity of temperance will be, per se, and naturally, to be the virtue of the desiderative part of the soul.

Aristotle, Topics. Book V, Chapter 7

In the next place, from cases, peculiarity indeed is subverted, if case is not the peculiarity of case; for neither will this case, be the peculiarity of that. Thus, since that which is beautifully, is not the peculiarity of that which is justly, the beautiful will not be the peculiarity of the just. But it is confirmed, if case is the peculiarity of case; for then this case will be the peculiarity of that case. Thus, since pedestrious biped is the peculiarity of man in the nominative case, it will also be the peculiarity of man in the dative case, i.e. it will be attributed to man. Cases, however, ought not only to be considered in that which is proposed, but also in opposites, as was observed in the former places. And peculiarity is subverted, indeed, if the case of the opposite or opposed thing, is not the peculiarity of the case of the opposite thing; for neither will the case of this opposite thing, be the peculiarity of the case of that opposite thing. Thus, since that which is done well, is not the peculiarity of that which is done justly; that which is done ill, will not be the peculiarity of that which is done unjustly. But peculiarity is confirmed, if the case of an opposite thing is the peculiarity of the case of the opposite thing; for, the case of this opposite thing, will be the peculiarity of the case of that opposite thing. Thus, since that which is best is the peculiarity of good; that which is worst will also be the peculiarity of evil. In the next place, from things which subsist similarly, peculiarity is, indeed, subverted, if that which subsists similarly, is not the peculiarity of that which has a similar subsistence; for neither will this thing which subsists similarly, be the peculiarity of that which has a similar subsistence. Thus, since the builder of a house, subsists similarly with respect to producing a house, as the physician with respect to producing health; but it is not the peculiarity of the physician to produce health; neither will it be the peculiarity of the builder of a house to produce a house. But it is confirmed, if that which subsists similarly, is the peculiarity of that which has a similar subsistence; for this which subsists similarly, will be the peculiarity of that which has a similar subsistence. Thus, since the physician subsists similarly with respect to the being effective of health, as the master of gymnastic exercises to the being effective of a good habit of body; but the peculiarity of a master of gymnastic exercises, is to be effective of a good habit of body; the peculiarity of a physician will be, to be effective of health. In the next place, from things which subsist after the same manner, peculiarity is subverted indeed, if that which subsists after the same manner, is not the peculiarity of that which subsists after the same manner; for neither will that which subsists after the same manner, be the peculia:rity of this which subsists after the same manner. But if of that which subsists after the same manner, that which subsists after the same manner is the peculiarity; it will not be the peculiarity of this thing, of which it was posited to be the peculiarity. Thus, since prudence subsists after the same manner with respect to the beautiful and the base, because there is a science of each of them; but to be the science of the beautiful is not the peculiarity of prudence; it will not be the peculiarity of prudence to be the science of the base. But if to be the science of the beautiful, is the peculiarity of prudence; it will not be the peculiarity of it to be the science of the base; for it is impossible that the same thing should be the peculiarity of many things. To him who confirms, however, this place affords no utility; for that which subsists after the same manner is one thing compared with many things. In the next place, peculiarity is subverted, if that which is said to exist, is not the peculiarity of that which is said to exist. For neither will to be corrupted be the peculiliarity of that which is said to be corrupted, nor to be generated, of that which is said to be generated. Thus, since to be an animal is not the peculiarity of man, heither will to be generated an animal be the peculiarity of to be generated a man; nor will the corruption of animal be the peculiarity of the corruption of man: After the same manner, the argurnent must be assumed from being genenerated becoming to be, or passing into existence to existence and being corrupted, and from being corrupted, to existence, and being generated, just as was now said, from existence to the being generated and corrupted. But peculiarity is confirmed, if that which is arranged according to existence is the peculiarity of that which is arranged according to existence. For that which is said to be according to the being generated, will also be the peculiarity of that which is said to be according to the being generated; and of that which is said to be corrupted, the peculiarity will be that which is assigned according to the being corrupted. Thus, since to be mortal is the peculiarity of man; to be generated mortal will also be the peculiarity of the being generated man; and the corruption of mortal will be the peculiarity of the corruption of man. After the same manner also, the argument must be assumed from the being generated, and from the being corrupted, with respect to the existence and generation of the same things from the sames, as was observed to him who subverts. In the next place, it is requisite to look to the idea of the thing proposed. And peculiarity indeed is subverted, if it is not present with the idea, or not so far as the idea is said to be of that, of which the peculiarity is assigned; for that which is posited to be, will not be, the peculiarity. Thus, since rest is not present with man-itself, so far as it is man, but so far as it is idea; rest will not be the peculiarity of man. But peculiarity is confirmed, if it is present with the idea, and so far is present as it is predicated of this very thing, of which it is posited not to be the peculiarity; for that which is posited not to be, will be, the peculiarity. Thus, since to consist from soul and body is present with animal-itself, and this is present with it so far as it is animal; to consist from soul and body will be peculiarity of animal.

Aristotle, Topics. Book V, Chapter 8

In the next place, arguments are to be framed from the more and the less. And in the first place, indeed, peculiarity is subverted, if the more is not the peculiarity of the more; for neither will the less be the peculiarity of the less, nor the least of that which is least, nor the especially of the especially, northe simply of the simply. Thus, since to be more coloured, is not the peculiarity of that which is more body, neither will to be less coloured be the peculiarity of that which is less body; nor, in short, will to be coloured be the peculiarity of body. But peculiarity is confirmed, if the more is the peculiarity of the more; for the less will be the peculiarity of the less, the least of the least, the especially of the especially, and the simply of the simply. Thus, since to perceive in a greater degree is the peculiarity of that which is more vital; to perceive in a less degree will be the peculiarity of that which is less vital; to perceive especially, of that which is especially vital; to perceive in the least degree, of that which is in the least degree vital; and to perceive simply, of that which is simply vital. From the simply, too, it must be considered by him who subverts, whether that which is simply, is not the peculiarity of that which is simply; for neither will the more be the peculiarity of the more, nor the less of the less, nor the especially of the especially, nor the least of the least. Thus, since to be worthy, is not the peculiarity of man, to be more worthy will not be the peculiarity of that which is more man. But by him who confirms, it must be considered whether that which is simply, is the peculiarity of that which is simply; for the more will be the peculiarity of the more, the less of the less, the least of the least, and the especially of the especially. Thus, since it is the peculiarity of fire, to tend upward naturally; it will also be the peculiarity of that which is more fire, to tend upward naturally in a greater degree. After the same manner, the attention must be directed from other things to all these. But in the second place, peculiarity is subverted, if the more is not the peculiarity of the more; for neither will the less be the peculiarity of the less. Thus, since it is more the peculiarity of animal to perceive sensibly, than of man to know scientifically; but it is not the peculiarity of animal to perceive sensibly, it will not be the peculiarity of man to know scientifically. Peculiarity, however, is confirmed, if the less is the peculiarity of the less; for the more will be the peculiarity of the more. Thus, since it is less the peculiarity of man to be naturally mild, than of animal to live; but it is the peculiarity of man to be naturally mild, it will be the peculiarity of animal to live. In the third place, peculiarity is subverted indeed, if any tbing is not the peculiarity of that of which it is more tbe peculiarity; for neither will this be the peculiarity of that of which it is less the peculiarity. But if it is the peculiarity of that, it will not be the peculiarity of this. Thus, since to be coloured, is more the peculiarity of superficies than of body; but it is not the peculiarity of superficies; to be coloured will not be the peculiarity of body. But if it is the peculiarity of superficies, it will not be the peculiarity of body. But to him who confirms, this place is not useful; for it is impossible that the same thing should be the peculiarity of many things. In the fourth place, peculiarity is subverted, if that which is more the peculiarity of the thing proposed is not the peculiarity of it; for neither will that which is less the peculiarity of it, be the peculiarity of it. Thus, since the sensible is more the peculiarity of animal than the partible; but the sensible is not the peculiarity of animal; the partible will not be the peculiarity of animal. But it is confirmed, if that which is less the peculiarity of the thing proposed is the peculiarity of it; for that which is more the peculiarity of it, will be the peculiarity of it. Thus, since to perceive sensibly, is less the peculiarity of animal, than to live; but to perceive sensibly, is the peculiarity of animal; to live will be the peculiarity of animal. In the next place, arguments must be formed from things which have a similitude of existence. And in the first place, indeed, peculiarity is subverted, if that which is similarly the peculiarity, is not the peculiarity of that, of which it is similarly the peculiarity; for neither will that which is similarly peculiarity, be the peculiarity of this thing, of which it is similarly the peculiarity. Thus, since it is similarly the peculiarity of the desiderative part of the soul, to desire, and of the reasoning part to reason; but to desire is not the peculiarity of the desidetative part; to reason will not be the peculiarity of the reasoning part. But peculiarity is confirmed, if that which is similarly peculiarity, is the peculiarity of this thing, of which it is similarly the peculiarity; for that which is similarly peculiarity, will be the peculiarity of this thing, of which it is similarly the peculiarity. Thus, since that which is primarily prudent is similarly the peculiarity of the reasoning part, and that which is primarily temperate of the desiderstive part; but that which is primarily prudent is the peculiarity of the reasoning part; that which is primarily temperate, will be the the peculiarity of the desiderative part. In the second place, peculiarity is subverted, if that which is similarly the peculiarity of a thing, is not the peculiarity of it; for neither will this thing which is similarly peculiarity, be the peculiarity of it. Thus, since it is similarly the peculiarity of man to see and hear; but it is not the peculiarity of man to see; it will not be the peculiarity of man to hear. But it is confirmed, if that which is similarly the peculiarity of this thing, is the peculiarity of it; for this also, which is similarly the peculiarity of it, will be its peculiarity. Thus, since it is similarly the peculiarity of the soul, that a part of it is primarily desiderative and ratiocinative; but it is the peculiarity of the soul, that a part of it is primarily desiderative; it will also be the peculiarity of the soul, that a part of it is primarily ratiocinative. In the third place, it is subverted, if it is not the peculiarity of that of which it is similarly the peculiarity; for neither will it be the peculiarity of this thing, of which it is similarly the peculiarity. But if it is the peculiarity of that, it will not be the peculiarity of the other. Thus, since to burn is similarly the peculiarity of flame, and a burning coal; but it is not the peculiarity of flame to burn, neither will it be the peculiarity of a burning coal to burn. But if it is the peculiarity of flame, it will not be the peculiarity of a burning coal. This place, however, affords no utility to him who confirms. But the place from things which are similarly affected, differs from the place from things which exist similarly; because the one is assumed according to analogy, and is not surveyed, in consequence of something being inherent; but the other is compared, because something is inherent. Because the same thing cannot be the peculiarity of many things.

Aristotle, Topics. Book V, Chapter 9

In the next place, peculiarity is subverted, indeed, if he who assigns it in capacity, assigns that peculiarity in capacity, to that which is not, since it is impossible that capacity should be present with a non-entity; for that which is posited to be, will not be, peculiarity. Thus, since he who says that the peculiarity of the air, is that which may be respired, assigns peculiarity in capacity; (for a thing of this kind, is that which is capable of being respired); but also assigns the peculiarity to that which is not; for though an animal should not exist which is naturally adapted to respire the air, yet the air may exist; though if animal is not, it is not possible to respire; hence, a thing which is of that kind that it may be respired, will not then be the peculiarity of the air, when there will not be an animal of such a kind as to respire. Hence, that which may be respired will not be the peculiarity of the air. But peculiarity is confirmed, if he who assigns it in capacity, either assigns it to that which is, or to that which is not, when capacity may be present with that which is not; for that which is posited not to be, will be, peculiarity. Thus, since he who assigns as the peculiarity of being, the ability to suffer, or to act, assigns peculiarity to being; (for when being is; it is also able to suffer or do something); hence, to be able to suffer or act, will be the peculiarity of being. In the next place, peculiarity will be subverted, indeed, if it is posited in an hyperbole; for that which is posited to be, will not be, the peculiarity. For it happens to those who thus assign peculiarity, that the name is not verified of that of which the sentence is verified; for the thing being corrupted, nevertheless, the sentence will remain; since it will especially be present with some one of the things that exist. Thus, if some one should assign the peculiarity of fire to be the most light body; though fire should be corrupted, there will he a certain body which will be most light. Hence, a body the most light will not be the peculiarity of fire. Peculiarity, however, is confirmed, if it is not posited in an hyperbole; for so far as pertains to this, it will be well posited. Thus, since he who asserts that the peculiarity of man is, an animal naturally mild, does not assign peculiarity in an hyperbole; peculiarity, so far as pertains to this, will be well posited.

Aristotle, Topics. Book VI, Chapter 1

Book VI, Chapter 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14

The discussion of definition consists of five parts. For either definition is reprehended, because it is not true to assert, that the sentence is predicated of that of which the name is predicated; (for it is necessary that the definition of man should be verified of every man) or because, since there is a genus, it does not place the thing defined in the genus, or does not place it in its proper genus. For it is necessary that he who defines, when he arranges the thing defined, in genus, should add the differences; since, of those things which are posited in definition, genus especially appears to signify the essence of the thing defined. Or definition is reprehended, because it is not peculiar; (for it is necessary that definition should be peculiar., as has been before observed) or because, though it should accomplish all the particulars before-mentioned, yet it does not define, nor assert what the very nature is of the thing defined. And, in addition to what has been already mentioned, definition is reprehended if it defines, indeed, but does not well define. Whether, therefore, the sentence also is not verified of that of which the name is verified, must be considered from places pertaining to accident. For there also, the whole consideration is whether they are true or not true. For when by discussion we show that accident is inherent, we say that it is true; but when we show that it is not inherent, we say that it is not true. But whether the assigned definition is not posited in its proper genus, or is not proper, must be considered. from the places pertaining to genus, and peculiarity. It remains, therefore, to show how an enquiry is to be made; whether a thing is not defined, or whether it is not rightly defined. Hence, in the first place, we must consider whether it is not rightly defined; for it is more easy merely to do any thing, than to do it well. It is evident, therefore, that an error more frequently takes place about this, because it is more difficult; so that reasoning about this, is easier than about that. But of the enquiry whether a thing is not rightly defined, there are two parts; one, whether obscurity is employed in the interpretation; (for it is necessary that he who defines, should, as much as possible, employ the clearest interpretation, since definition is assigned for the sake of knowledge) and the other, whether more is said in the definition than is requisite; for every thing which is added in the definition is superfluous. But again, each of the before-mentioned places, is distributed into many parts.

Aristotle, Topics. Book VI, Chapter 2

One place, therefore, pertaining to obscurity is, if some word in the definition is homonymous; as, if some one should define generation to be a leading to essence; or health to be the symmetry of things hot and cold. For the words leading and symmetry are homonymous. It is manifest, therefore, which of the things that are signified by that which is multifariously predicated is intended to be asserted. The like will also take place, if when the thing defined is multifariously predicated, the definition is not given with distinction; for it will be immanifest what the subject is of the definition; and it will be possible to cavil, as if the definition were not adapted to every thing of which the definition is assigned. A thing of this kind, however, will especially happen to take place, when equivocation is latent. It is also possible, that when that which is assigned in the definition is distinguished, and it is explained in how many ways it is predicated, a syllogism may be formed. For if the definition is not sufficiently given in any signification, it is evident, that according to that mode, the thing will not be defined. Another place is, if the definition is given metaphorically; as if it should be said that science is that which cannot fall; or, that the earth is a nurse; or, that temperance is symphony. For every thing which is said metaphorically is obscure. It is also possible to calumniate him who uses a metaphor, as not speaking properly; for the given definition will not be adapted to the thing defined; as, for instance, in temperance; for all symphony is in sounds. Farther still, if symphony is the genus of temperance, the same thing will be in two genera which do not contain each other. For neither does symphony contain virtue, nor virtue symphony. Again, he also defines obscurely who does not use names which are generally adnpted; as Plato, who defines the eye to be that which is shaded by the eyebrows; or a spider, a feeder on putridity; or the marrow, bone-begetter. For every word which is unusual, is obscure. Some things, however, are asserted neither equivocally, nor metaphorically, nor properly. As if law should be defined to be a measure, or an image of things naturally just. But all such things are worse than metaphor. For metaphor causes, in a certain respect, that which is signified to be known, on account of similitude; since all those who use metaphors, employ them according to a certain similitude. A thing of such a kind, however, as we have just mentioned, does not cause a thing to be known. For neither is there any similitude, according to which law is a measure, or an image; nor is it accustomed to be properly predicated. Hence, if it should be said that law is properly a measure, or an image, he who says this, speaks falsely. For that is an image, the generation of which is through imitation; but this does not exist in law. But if it is not properly a measure or an image, it is evident that he speaks obscurely, and that what he says is worse than any thing which is spoken metaphorically. Again, definition is properly reprehended, if from what is said, the definition of the contrary is not evident; for those who well define, also signify at the same time contraries. Or it is reprehended if it is not of itself evident, of what the definition is which is given. For in this case it resembles ancient pictures, the subject of which could not be known without a superscription. Whether, therefore, definition is obscure, may be considered from places of this kind.

Aristotle, Topics. Book VI, Chapter 3

If, however, more should be said in the definition than is requisite, in the first place, it must be considered whether any thing is employed which is present with all things, or simply, with beings, or with those things which are under the same genus with the things defined; for of this, more will necessarily be asserted than is requisite. For it is necessary to separate genus, indeed, from other things; but difference, from some one of the things which are in the same genus. Hence, that which is present with all things, is simply separated from nothing. But that which is present with all things contained under the same genus, is not separated from those things which are in the same genus; so that an addition of this kind is vain. Or, it must be considered whether that which is added is peculiar; but this being taken away, the remaining definition is proper, and manifests essence. Thus, in the definition of man, if receptive of science, is added, the definition is superfluous; for this being taken away, the remaining definition is proper, and manifests the essence of man. But, in short, every thing is superfluous, which, when taken away, the remainder causes the thing defined to be manifest. Such also is the definition of the soul, if it is number moving itself. For that which itself moves itself is soul; according to the definition of Plato. Or shall we say, that this which has been just now mentioned, is, indeed, peculiarity, yet does not manifest essence, when number is taken away? In whichever way, however, the thing exists, it is difficult to explain. But this place must be used, in all such things, as may be expedient. Thus, the definition of phlegm is the first unconcocted moisture arising from food. For there is one first moisture, not many. Hence the addition of unconcocted is superfluous; for this being taken away, that which remains will be the proper definition. For it is not possible that this, and something else, should be the first moisture arising from food. Or shall we say, that phlegm is not simply the first thing arising from food, but the first of those things which are unconcocted? So that the word unconcocted must be added. For if this be admitted, the definition will not be true, since it is not the first of all things. Farther still, it must be considered, whether some one of those things which are in the definition, is not present with all those that are under the same species. For a definition of this kind. is subordinate to those things in which that is employed which is present with all things. For in that way of defining the remainder will be the proper definition, and the whole will be peculiar; since, in short, if any thing which is true is added to peculiarity, the whole definition will be proper. But if some one of the things which are in the definition, is not present with all those which are under the same species, it isimpossible that the whole definition should be proper; for it will not be reciprocally predicated of the thing; as, for instance, a biped pedestrious animal of four cubits. For a definition of this kind is not reciprocally predicated of the thing, because the dimension of four cubits, is not present with all those things which are under the same species. Again, it must be considered, whether the same thing is frequently asserted; as, he who says that desire is the appetite of the pleasant. For all desire is of the pleasant: so that, what is the same with desire, will also be of the pleasant. The definition, therefore, of desire is, the appetite of the pleasant; (for there is no difference between saying desire, and, the appetite of the pleasant) so that each of these will pertain to the pleasant. Or shall we say, that this is not at all absurd? For man is a biped; so that what is the same with man, will also be a biped. But, a pedestrious biped animal, is the same with man. Hence, a pedestrious biped animal, is a biped. Nothing absurd, however, happens on this account. For biped is not twice predicated of pedestrious animal; (for thus biped would be twice predicated about the same thing) but biped is predicated about pedestrious biped animal. Hence, biped is only once predicated. The like also takes place in desire. For to be of, or pertain to, the pleasant, is not predicated of appetite, but of the whole sentence; so that here also the predication is but once. It is not, however, absurd, that the same name should be twice pronounced; but it is absurd that the same thing should be frequently predicated about a certain thing; as when Xenocrates says that prudence is definitive and contemplative of beings. For the definitive is something contemplative; so that he twice says the same thing, again adding the word contemplative. Those also act in a similar manner who say that refrigeration is a privation of natural heat; for all privation is of that which exists according to nature; so that it is superfluous to add, according to nature; but it would have been sufficient to say, that it is the privation of heat, since privation itself makes it known, that it is asserted of that which is according to nature. Again, it must be considered whether that which is universally asserted, adds something which is partial; as if equity should be defined to be the diminution of things profitable and just; for the just is something profitable, and therefore is contained in the profitable. Hence, the word just is superfluous. He therefore who thus defines adds the partial, when he speaks of the universal. The like also takes place if some one should define medicine to be the science of things salubrious to animal and man; or law, to be the image of things naturally beautiful and just. For the just is something beautiful; so that he will say the same thing frequently. Whether, therefore, a thing is well or not well defined, must be considered through these, and places of this kind.

Aristotle, Topics. Book VI, Chapter 4

Whether, however, he who defines asserts, and defines what a thing is, or not, must be considered from what follows: And in the first place, if he does not frame the definition, from things prior andmore known. For since definition is delivered for the sake of knowing what is said; but we know this, not from things casual, but from things prior and more known; (as in demonstrations, for thus all doctrine and discipline subsists), it is evident, that he who does not define through things of this kind, does not truly define. For if he defines, there will be many definitions of the same thing. For it is evident, that he who defines through things prior and more known, will define in a better manner; so that both definitions will be of the same thing. This, however, does not appear to be the case; for to every being, to be that which it is, is one thing. Hence, if there will be many definitions of the same thing, there will be the same essence of the thing defined, as is manifested by each of the definitions. But these essences are not the same; because the definitions also are different. It is evident; therefore, that he does not define, who does not define from things prior and more known. Hence, that a definition is not framed through things more known, may be assumed in a twofold respect; either, if it is simply, from things more unknown, or if from things which are unknown to us. For both these are possible. That which is prior, therefore, is simply more known than that which is posterior; as a point than a line; a line, than a superficies; and a superficies than a solid. Thus also the monad is more known than number; for it is prior to, and the principle of every number; and in a similar manner a letter is more known than a syllable. To us, however, it sometimes happens vice-versa. For a solid especially falls under sense; but a superficies more so than a line; and a line more than a point. Hence, the multitude know things of this kind in a greater degree. For some things may be learnt by any casual person; but to learn others is the province of an accurate and transcendent mind. Simply, therefore, it is better to endeavour to know things posterior through such as are prior; for a thing of this kind is more scientific. Nevertheless, by those who are incapable of knowing through things of this kind, it is perhaps necessary to frame the definition through things which are known to them. But the definition of a point, of a line, and of a superficies, are among definitions of this kind; for all of them manifest things prior, through such as are posterior. For the first they say is the boundary of a line; the second of a superficies; and the third of a solid. It is necessary, however, not to be ignorant, that those who thus define, cannot manifest what the very nature is of the thing defined, unless it should happen that the same thing is more known to us, and is simply more known; since it is necessary, that he who  wells defines should define through genus and differences; and these are among the number of things which are simply more known than, and prior to, species. For genus and difference co-subvert species; so that these are prior to species. They are also more known. For species being known, it is also necessary that genus and difference should be known; for he who knows man, knows also animal and pedestrious. But when genus or difference is known, it is not necessary, that species also should be known; so that species is more unknown. Again, it happens to those who in reality say, that things of this kind are definitions, which consist of things known to every one, that they assert there are many definitions of the same thing. For some things are more known to some person, and the same things are not more known to all. Hence, with a different person. there will be a different definition, if it were requisite that definition should be framed from things more known to every one. Farther still, to the same persons, at a certain time, some things are more known than others. For at first, sensibles are more known to them; but vice-versa, when they obtain a more accurate knowledge. Hence, neither can it be said by those who assert that definition is through things more known to every one, that there is always the same definition with the same person. It is evident, therefore, that we must not define from things of this kind, but from such as are simply more known; for thus only, one and the same definition will always be produced. Perhaps, however, that which is simply known, is not that which is known to all men, but that which is known to those whose dianoetic part is well disposed; just as that which is simply salubrious, is that which is salubrious to those whose body is in a good condition. Hence, it is necessary that every thing of this kind should be accurately explained; and should be employed by those who dispute, so far as is expedient. But it is especially acknowledged, that definition may be subverted, if it is neither composed from things simply more known, nor from those which are more known to us. One place, therefore, of proving that definition is uot through things more known, is, when things prior are rendered manifest through such as are posterior, as we have before observed. Another place is, if the definition of that which is at rest and definite, is assigned through the indefinite, and that which is in motion. For that which is permanent and definite, is prior to, and more known than that which is indefinite, and in motion. There are three places, however, for the purpose of proving that a definition is not from things that are prior. The first is, if the opposite is defined through opposites; as for instance, good through evil; for opposites are naturally simultaneous. But to some persons it appears that there is the same science of both; so that the one is not more known than the other. It is necessary, however, not to be ignorant, that some things perhaps cannot be otherwise defined. Thus the double cannot be defined without the half; and such things as are relatives per se. For in all these, there is the same essence, and they are in a certain respect relatives; so that it is impossible for the one to be known without the other. Hence, it is necessary that in the definition of the one, the other also should be comprehended. lt is, necessary, therefore, that all such things should be known, and that these places should be employed in them, in such a manner as may appear to be useful. Another place is, if in the definition the thing defined is employed. But this is latent when the name of the thing defined is not used; as if some one should define the sun to be a star apparent in the day. For he who uses the word day, uses also the word sun. In order, however, to detect of this kind, it is necessary to assume definition instead of a name; as that day is the motion of the sun above the earth. For it is evident that he who says the motion of the sun above the earth, mentions the sun; so that he who uses the word day, uses also the word sun. Again, another place is, if that which is in an opposite division, is defined by that which is in an opposite division; as if the odd should be defined to be that which is greater than the even by unity. For things are naturally simultaneous, which are oppositely divided from the same gem1s; but the odd and the even are oppositely divided; for both are the differences of number. In a smiliar manner also, if the superior is defined through things inferior; as, if it should be said that the even number, is that which may be divided into two parts; or that good is a habit of virtue. For the term, into two parts: is assumed from two, which is an even number; and virtue is a certain good; so that these are under those. It is necessary, however, that he who uses the inferior, should also use the thing defined. For he who uses virtue, uses good, since virtue is a certain good. In like manner, he who uses the term in two parts, uses the even number, because a division into two parts signifies a division into two; but two is an even number. Universally, therefore, one place is this, that a definition is not framed through things prior and more known; but the parts of it are those which have been enumerated.

Aristotle, Topics. Book VI, Chapter 5

The second place is, if when a thing is in genus, it is not posited to be in genus, by him who proposes the thesis. But in all those things there is an error of this kind in the definition of which, what a thing is, is not previously declared; and such is the definition of body, that it is that which has three dimensions. Or if some one should define man to be, that which knows how to number; but the genus wishes to signify what a thing is, and is that which is first supposed of the things predicated in definition. Again, another place is if when the thing defined pertains to many things, it is not adapted to all of them; as if some one should define grammar to be the science of writing what is dictated; for the words and of reading also, are wanting to the definition. For he no less defines grammar, who defines it to be the art of reading, than he who defines it to be the art of writing. Hence, neither of these defines, but he who says that grammar is both these; since there cannot be many definitions of the same thing. In some things, therefore, the case is in reality what we have mentioned; but in others it is not; as in those things which do not essentially pertain to both. Thus, medicine is the science of producing health and disease; for of the former, it is said to be the science per se; but of the latter from accident. For it is entirely foreign from medicine to produce disease. Hence, he does not more define who refers to both these, than he who refers to one of them; but perhaps he defines in a worse manner; because any other person is able to produce disease. Farther still, he errs who does not refer to that which is better, but to that which is worse, since there are many things to which the thing defined pertains. For every science, and every power appear to pertain to that which is best. Again, whether that which is asserted is not posited in its proper genus, must be considered from the elements pertaining to genera, as was before observed. Farther still, he errs who speaks of genera transcendentally; as, he who defines justice to be a habit productive of equality, or distributive of the equal. For he who thus defines passes beyond virtue. Hence, omitting the genus of justice, he does not say what the very nature of it is; for the essence of every thing is in conjunction with genus. But this is the same thing as to say, that he does not place the thing defined in the nearest genus. For he who places it in the nearest genus, has mentioned all the superior genera; since all the superior are predicated of the inferior genera. Hence, that which. is defined must either be placed in the nearest genus, or all the differences through which the nearest genus is defined must be added to the superior genus. For thus, nothing will be omitted, but in the definition, instead of a name, the inferior genus will be mentioned. But he who alone speaks of the superior genus, does not also speak of the inferior genus. For he who says a thing is a plant, does not also say it is a tree.

Aristotle, Topics. Book VI, Chapter 6

Again, in differences, it must in a similar manner be considered whether the differences of genus are introduced. For unless he who defines, defines by the proper difterences of a thing; or if he entirely asserts a thing of such a kind as cannot be the difference of any thing; as, animal, or essence; it is evident that he does not define; for these are not the differences of any thing. It is also necessary to see whether any thing is divided oppositely to the difference which is mentioned. For if there is not, it is evident, that what is mentioned will not be the difference of genus. For every genus is divided by differences which have an opposite division; as, animal, by the pedestrious and winged, by the aquatic and biped. Or if there is, indeed, a certain oppositely divided difference, but it is not verified of the genus. For it is evident, that neither will be the difference of the genus; since all differences which are oppositely divided, are verified of their proper genus. In a similar manner also he errs, if difference is, indeed, verified of genus; but when added to genus, does not produce species. For it is evident, that this will not be the specific difference of genus; since every specific difference, in conjunction with genus, produces species. But if this is not the difference, neither will that which was mentioned, since it is divided oppositely to this. Again, he also errs, if he divides genus by negation; as, those who define a line to be a length without breadth. For this signifies nothing else than that it has no breadth. It happens, therefore, that the genus participates of the species; for every length. is either without breadth, or has breadth; since, of every thing, either affirmation or negation is verified. Hence also, the genus of a line, which is length, will either be without breadth, or will have breadth.  But length without breadth is the definition of the species; and in a similar manner, length with breadth. For the privation of breadth, and the possession of breadth, are differences; and the definition of species, is from difference and genus. Hence, genus will receive the definition of species; and in a similar manner, the definition of difference; since, one of the before-mentioned differences is necessarily predicated of genus. But this place is useful against those who assert that here are ideas. For if there is length itself, how will the possession or privatton of breadth be predicated of the genus? For it is necessary that one of these should be verified of every length, if it is to be verified of the genus. This, however, does not happen to be the case. For there are lengths which are without breadth, and lengths which have breadth. Hence, this place is useful against those alone, who say that genus is one in number. But this is asserted by those alone who admit that there are ideas; for they say that length itself, and animal itself are genera. Perhaps, however, in some things, it is necessary, that he who defines should use negation; as, in privations. For that thing is blind which has not sight, when it is naturally adapted to possess it. But it makes no difference, whether genus is divided by negation, or by an affirmation of that kind to which it is necessary negation should be oppositely divided; as, if some one should define length to be that which has breadth. For to that which has breadth, that which has not breadth is oppositely divided, but nothing else; so that the genus is again divided by negation. Again, it must be considered whether species is assigned as difference; as it is by those who define contumely to be insolence together with derision. For derision is a certain insolence; so that derision is not a difference, but a species. Farther still, it must be considered whether genus is assigned as difference; as it is by those who say that virtue is a good or a worthy habit; for good is the genus of virtue. Or, shall we say, that good is not a genus, but a difference. Since, it is true, that it is not possible that the same thing can be in two genera, which do not comprehend each other. For neither does good contain habit, nor habit good; since, not every habit is good, nor every thing good is a habit. Hence, both will not be the genera of virtue. If, therefore, habit is the genus of virtue, it is evident, that good is not the genus, but is rather the difference of it. Farther still, habit signifies what virtue is; but good does not signify what it is, but what kind of thing it is. But difference appears to signify the quality of a thing. It is also requisite to consider, whether the given difference does not signify quality, but this particular definite thing, for every difference appears to signify a certain quality. It must likewise be considered, whether difference is present from accident with the thing defined. For no difference is iri the number of things, which are present from accident, as, neither is genus; since it is not possible that difference should be present and not present with a certain thing. Again, if difference or species is predicated of genus, or something which is the subject of species, there will not be a definition. For nothing that has been now mentioned can be predicated of genus; because genus is more widely extended than all these. Again, it must be considered, whether genus is predicated of difference; for genus appears to be predicated, not of difference, but of those things of which difference is predicated. Thus, animal is predicated of man and ox, and other pedestrious animals, and not of difference itself, which is predicated of species. For if animal were predicated of each of the differences, many animals would be predicated of the species; for differences are predicated of species. Again, all differences will either be species or individuals, if they are animals; for every animal is either species or an individual. In a similar manner also, it must be considered, whether species, or some one of the things which are under species, is predicated of difference. For this is impossible; because difference is predicated to a greater extent than species. Farther still, it will happen that difference is species, if a certain species is predicated of it. For if man is predicated of difference, it is evident, that difference is man. Again, it must be considered, whether difference is not prior to species. For it is necessary, that difference should be posterior to genus, but prior to species. It must likewise be considered, whether the assigned difference, is of another genus, which is neither contained by, nor contains it. For the same difference does not appear to be the difference of two genera, which do not comprehend each other; since, otherwise, it would happen that the same species would be in two genera, which do not comprehend each other. For each difference introduces its appropriate genus; just as pedestrious and biped co-introduce animal. Hence, if of that of which the difference, each of the genera is predicated; it is evident, that the species is in two genera, which do not comprehend each other. Or, shall we say, that it is not impossible there may be the same difference of two genera, which do not comprehend each other; but that it must be added, neither are both contained under the same genus? For pedestrious animal, and winged animal, are genera, which do not comprehend each other; and biped is the difference of both of them. Hence, it must be added, that neither are both of them under the same genus. For both these are under animal. It is also erident, that it is not necessary that every difference should introduce an appropriate genus; since it is possible that tliere may be the same difference of two genera, which do not comprehend each other; and that one of them alone, and all which are above it, should necessarily co-introduce; just as biped, winged, or pedestrious, co-introduce animal. It is likewise necessary to see whether to be in a certain thing, is assigned as the difference of essence. For essence does not appear to differ from essence by being somewhere. Hence, those are blamed who divide animal by the pedestrious and the aquatic, as, if the pedestrious and the aquatic signified the being somewhere. Or, shall we say, that in these things they are not rightly blamed? For the aquatic and the terrestrial, do not signify the being in something, and the being somewhere, but they signify a certain quality. For that which is aquatic will be similarly so, though it should be in a dry place. And that which is terrestrial, will be similarly terrestrial, though it should be in a moist place, and will not be aquatic. At the same time, if ever difference signifies to be in a certain thing, it is evident, that he who defines will err. Again, it must be considered, whether passive quality is assigned as difference. For every passive quality, when it is increased, removes essence from its condition; but difference is not a thing of this kind. For difference rather appears to preserve that in its condition of which it is the difference. And it is simply impossible that any thing should be (i.e. remain) without a proper difference; for pedestrious not existing, there will not be man. In short, no one of those things according to which that which possesses is changed in quality, is the difference of the thing that possesses; for all such things, when they are increased, remove essence from its condition. Hence, he who assigns a certain difference of this kind, errs; for, in short, we are not changed in quality according to differences. He also errs who assigns the difference of a certain relative, not with reference to something else. For of relatives, the differences also are relatives; as may be seen in science. For it is said to be contemplative, practical, and effective; but each of these signifies relation. For science is contemplative of something, and is effective and practical of something. It is likewise requisite to consider, whether he who defines, assigns that to which each relative is naturally adapted. For some things can only be used for that to which each relative is naturally adapted, but for nothing else. Thus, the sight can alone be used for the purpose of seeing. But other things can be used for something else. Thus, some one may draw up a weight with a strigil; but at the same time, he who defines a strigil to be an instrument for the purpose of drawing, errs; for it is not naturally adapted to this. But the definition of that to which a thing is naturally adapted is, that for which a prudent man, so far as he is prudent, will use it, and the science which properly belongs to it. Farther still, it must be considered, whether the definition is assigned of that which is first, when it pertains to many things; as, if some one should define prudence to be the virtue of man, or of the soul, and not of the reasoning power. For prudence is primarily the virtue of this power; since, according to this, both the soul and man are said to be prudent. Again, an erroris committed in defining, unless that is receptive, of which the thing defined is the property, or disposition, or something else. For every disposition, and every property, is naturally adapted to be generated in that of which it is the disposition or property; as, science is generated in the soul, being a disposition of the soul. Sometimes, however, an error is committed in things of this kind; as by those who say, that sleep is the imbecility of sense; that doubt is the equality of contrary arguments; and that pain is a separation accompanied with violence, of connasccnt parts. For neither is sleep present with sense; but it would be necessary that it should, if it were imbecility of sense. In a similar manner, neither is doubt present with contrary arguments; nor pain with connascent parts. For things inanimate would suffer pain, since pain would be present with them. Such, also, is the definition of health, if it is the symmetry of things hot and cold. For it is necessary, that things hot and cold should be well; since the symmetry of every thing is in those things of which it is the symmetry; so that health also would be in things hot and cold. Again, it happens that those who thus define, reduce that which is made to the effective, or vice versa. For the separation of connascent parts is not pain, but is effective of pain; nor is the imbecility of sense sleep, but the one produces the other. For either we sleep in consequence of imbecility, or we become imbecil in consequence of sleep. In a similar manner also, the equality of contrary arguments, will appear to be effective of doubt. For when we reason on both sides of a question, and every thing appears to us to have equal weight on each side, then we doubt which of them we shall adopt. Farther still, according to all times it must be considered, whether the definition is anywhere discordant; as, if some one should define the immortal, to be that which is now an incorruptible animal. For the animal which is now incorruptible, will be now immortal. Or, shall we say, that in this it does not happen? For the assertion that it is now incorruptible is ambiguous. For it either signifies that it is not now corrupted, or that it cannot now be corrupted, or that it is now a thing of that kind, which can never be corrupted. When, therefore, we say that the animal is now incorruptible, we do not say that now it is an animal of this kind, but that it is such an animal as will never be corrupted. And this is the same thing with the immortal. Hence, it does not happen that it is now immortal. At the same time, if it should ever happen, that what is assigned according to the definition is now inherent, or was before, but that which is according to the name is not inherent, it will not be the same. This place, therefore, must be used in the manner we have stated.

Aristotle, Topics. Book VI, Chapter 7

It must likewise be considered whether the thing defined may be more explained by another definition, than by that which was assigned; as, if justice should be defined to be, a power distributive of the equal. For he is rather a just man who deliberately chooses to distribute the equal, than he who is able. Hence, justice will not be a power distributive of the equal; for he would be especially just, who is most able to distribute the equal. Again, it must be considered whether the thing defined receives intension, but that which is assigned according to the definition, does not receive it; or whether, on the contrary, that which is assigned according to the definition receives, but the thing does not receive intension. For it is necessary either that both should receive it, or neither, if that which is assigned according to the definition is the same with the thing defined]. Farther still, it must be considered whether both indeed receive intension, but both do not at one and the same time receive an accession; as, if love is the desire of coition. For he who loves in a greater degree, does not desire coition in a greater degree; so that both do not at one and the same time receive intension. It is necessary, however, that they should, if they were the same. Again, it must be considered whether of two things proposed, of that of which the thing defined is predicated in a greater degree, that which is according to the definition is predicated in a less degree; as, if fire is a body of the most attenuated parts. For flame is in a greater degree fire than light; but a body consisting of the most attenuated parts, is in a less degree flame than light. It would be necessary, however, that both should in a greater degree be present with the same thing, if they were the same. Again, it must be considered whether the one is similarly present with both the things proposed; but the other is not similarly present with both, but in a greater degree with one of them. Farther still, whether the definition is accommodated to two things according to each of them; as if the beautiful should be defined to be that which is pleasant through the sight, or through the hearing; and being should be defined to be that which is able to suffer or to act. For at one and the same time, the same thing will be beautiful and not beautiful. And in a similar manner the same thing will be at one and the same time being and not being. For that which is pleasant through the hearing, will be the same with the beautiful; so that what is not pleasant through the hearing will be the same with that which is not beautiful. For those things which are opposed to the same things are the same. But that which is not beautiful is opposed to the beautiful; and that which is not pleasant through the hearing, is opposed to that which is pleasant through the hearing. It is evident, therefore, that what is not pleasant through the hearing, is the same with that which is not beautiful. Hence, if any thing is pleasant through the sight, but is not pleasant through the hearing, it will be beautiful and not beautiful. And in a similar manner we may show that the same thing is being and non-being. Again, framing definitions of genera and differences, and of every thing else which is assigned in definitions, instead of names it must be considered whether any one of them is discordant.

Aristotle, Topics. Book VI, Chapter 8

If, however, that which is defined should be a relative, either per se, or according to genus, it must be considered whether that to which it is referred either per se, or according to genus, is mentioned in the definition; as if some one should define science to be immutable opinion, or the will, appetite unattended with pain. .For. the essence of every thing which is a relative consists in a relation to something else; since the being of every thing which subsists with reference to another thing is the same with that of being in a certain respect referred to some thing. It is necessary, therefore, to say, that science is the opinion or apprehension of the object of science, and the will, the appetite of good. In a similar manner also, if some one should define grammar to be the science of letters; for it will be necessary in the definition to assign that to which the thing defined, or to which the genus is referred. It must also be considered whether the definition of a certain thing which is referred to something, is not assigned with reference to the end. But the end in every thing is that which is the best, or is that for the sake of which other things subsist. Either, therefore, that which is the best, or that which is last, must be adduced. Thus, for instance, it must be said that desire is not of the pleasant, but of pleasure; for we choose the pleasant for the sake of this. It must also be considered whether that to which a thing is referred, is generation or energy; since nothing of this kind is an end. For to have energized, and to have been generated, are rather the end, than to generate and to energize. Or, may we not say, that a thing of this kind is true in all things? For nearly most men rather wish to be delighted, than, having been delighted, to cease to be so; so that they rather make to energize the end, than to have energized. Again, in some things it must be considered whether there is not a definition of the quantity, or the quality, or the where, or according to other differences: as, with respect to the ambitious man, what the quality or the quantity is of the honour after which he aspires. For all men aspire after honour. Hence, it is not sufficient to say that he is ambitious who aspires after honour, but the above-mentioned differences must be added. In a similar manner, if an avaricious man is to be defined, the quantity of the riches which he desires must be mentioned; or if an incontinent man is to be defined, the quality of the pleasures with which he is conversant must be mentioned. For he is not said to be incontinent, who is vanquished by any pleasure whatever, but he who is vanquished by a certain pleasure. The same thing must be said of those definitions in which the night is defined to be the shadow of the earth; or an earthquake, the motion of the earth; or a cloud, the condensation of the air; or wind, the motion of the air. For the quantity, quality, the where, and by what, must be added. And in a similar manner with respect to other things of this kind; for he who omits any difference does not say what the very nature of a thing is. But it is ahvays necessary to argue against that which is wanting. For an earthquake will not be the motion of earth in any manner, or in any quantity; nor will wind be the motion of air, in any manner, or in any quantity. Farther still, in defining appetites also an error will be committed if that which appears is not added; and also, in other things to which this is adapted. As, if the will should be defined to be the appetite of good; but desire, the appetite of the pleasant; and not the appetite of that which appears to be good, or pleasant. For those who aspire after any thing, are frequently ignorant that it is good or pleasant. Hence, it is not necessary that it should be good or pleasant, but only that it should appear to be so. It is necessary, therefore, that the explanation should be made in this manner. But if that which has been mentioned should be assigned, he who asserts that there are ideas, must be led to ideas. For idea is not of any thing which is apparent; but form, or species, appears to be referred to form. Thus, desire-itself is of the pleasant-itself; and the will-itself, is of the good-itself. But the will-itself is not of apparent good; nor is desire-itself of the apparent pleasant. For it is absurd that there should be the self-apparent good, or pleasant.

Aristotle, Topics. Book VI, Chapter 9

Again, if the definition of habit should be proposed it must be considered in that which has or possesses it; but if the definition of that which has, it must be considered in habit. And in a similar manner in other things of this kind. Thus, if the pleasant is that which is beneficial, he who is pleased is benefited. And, in short, in definitions of this kind, it happens after a certain manner, that he who defines, defines more things than one. For he who defines science, after a certain manner, also defines ignorance; and in a similar manner he who possesses, and he who is without science; and also to know scientifically, and to be ignorant. For the first being manifest, after a manner, the rest also become manifest. In all such particulars, therefore, it must be considered lest any thing should be discordant, from those elements which are from contraries, and conjugates. Again, in those things which are relatives; it must be considered; whether to that to which genus is referred, a certain spedes also 1s referred. As, whether if opinion is referred to the object of opinion, a certain opinion also is referred to a certain object of opinion; and if the multiple is referred to the submultiple; whether also a certain multiple is referred to acertain submultiple. For if there is not such a reference, it is evident that there will be an error. It is likewise requisite to see whether there is an opposite definition of the opposite; as, whether the definition of the half is opposite to the definition of the double. For if the double is that which surpasses the equal; the half will be that which is surpassed in the equal. The like must also be considered in contraries. For the definition of the contrary will be contrary, according to one certain connexion of contraries. Thus, if that which is productive of good is beneficial; that which is productive of evil, or corruptive of good, is noxious. For it is necessary that one of these should be contrary to that which was mentioned from the first. Therefore, neither of them is contrary to that which was mentioned from the first, it is evident that neither of the definitions afterwards delivered, will be the definition of the contrary. Hence, neither will the definition given from the first, be rightly given. Since, however, there are some contraries which are said to be so by the privation of another; as inequality appears to be the privation of equality; (for things which are not equal, are said to be unequal), it is evident that what is said to be contrary to privation, is necessarily defined through the other; but that it is no longer necessary that what remains should also be defined through that which is predicated according to privation; for it would happen that each would become known through each. An error of this kind, therefore, must be considered in contraries; as, if some one should define equality to be, that which is contrary to irregularity; for thus equality is defined through that which is predicated according to privation. Farther still, it is necessary, that he who thus defines, should use in the definition the thing defined. But this will become manifest, if definition is assumed instead of a name. For since there is no difference between saying inequality, and the privation of equality; equality will be that which is contrary to the privation of equality; so that the thing defined will be employed. If, however, neither of the contraries should be predicated according to privation, but the definition should be similarly assigned; as, that good is that which is contrary to evil; it is evident that evil will be that which is contrary to good. For of things which are thus contrary, the definition must be similarly assigned; so that again it will happen that the thing defined will be employed. For good is inherent in the definition of evil. Hence, if good is that which is contrary to evil; but there is no difference between saying evil, and the contrary to good; good will be that which is contrary to the contrary to good. It is evident, therefore, that the thing defined is employed. Farther still, it must be considered whether he who assigns that which is predicated according to privation, does not assign that of which it is the privation; as, that it is the privation of habit, or of a contrary, or of something else; and whether he does not add that in which it is naturally adapted to be generated simply, or in which primarily it is adapted to be so generated. As if some one, when he says that ignorance is privation, should not say that it is a privation of science; or should not add the words in which it is naturally adapted to be generated; or having added them, should not farther add, in which primarily; as, not that it is in the reasoning power, but in man or soul. For if he should not add some one of these, he will err. The like will also take place, if he should not say that blindness is a privation of sight in the eye. For it is necessary that he who well assigns what privation is, should also assign of what it is the privation, and what that is which is deprived. It is likewise necessary to see, whether that is defined by privation, which is not predicated according to privation, which fault they will be seen to commit in the definition of ignorance, who do not speak of ignorance according to negation. For that which has not science, does not appear to be ignorant, but rather that which is deceived. Hence, we neither say that things inanimate, nor children, are ignorant; so that ignorance is not predicated according to the privation of science.

Aristotle, Topics. Book VI, Chapter 10

Again it must be considered whether similar cases of a detinition accord with similar cases of a noun. Thus, if the beneficial is that which is effective of health; whether beneficially is effectively of health; and that was beneficial, which was effective of health. It must likewise be considered whether the definition which is assigned accords with idea; for in some things it does not happen to accord. As if some one should define after the manner of Plato, who adds the word  mortal in the definitions of animals. For idea will not be mortal, as, for instance, man-itself. Hence, definition is not adapted to idea. But, in short, it is necessary that the definition of those things to which the effective, or the passive is added, should be discordant with idea; for ideas appear to those who say that there are ideas, to be impassive and immoveable. And against these, such like arguments are useful. Farther still, in those things which are predicated according to equivocation it must be considered, whether one common definition of all of them is assigned. For those things are synonymous of which there is one definition according to the name. Hence, the assigned definition is the peculiarity of no one of those things which are contained under the name; since the homonymous is similarly adapted to every thing. The definition of life given by Dionysius has this fault, if it is the motion of a genus which is nourished connascent, and consequent. For this no more pertains to animals than to plants; but life does not appear to be predicated according to one species; but one kind of life is in animals, and another in plants. It is possible, therefore, that a definition may designedly be thus assigned, as if all life were synonymous, and predicated according to one species. Nothing, however, hinders but that some one perceiving the equivocation, and wishing to assign the definition of the other, may be ignorant that he does not assign a proper definition, but that which is common to both. He will, however, no less err, if he defines in either way. But since some things which are homonymous are latent, he who interrogates ought to use them as things synonymous; for the definition of the one is not adapted to the other. Hence, after a manner he will appear not to have defined; since it is necessary that the synonymous should be adapted to every thing. But he who answers must distinguish by dividing. Since, however, some of those who answer, say, that what is synonymous is homonymous; when the assigned definition is not adapted to every thing; but that what is homonymous is synonymous, if it accords with both the things signified; hence, of these it must be previously acknowledged, or previously inferred by syllogism, that they are homonyrnous, or synonymous, or whatever else they may be, For they will more readily concede, who do not previously see what will happen. But if those who dispute should not agree, and some one should say, that what is synonymous is homonymous, because the assigned definition is not adapted to this; it must be considered, whether the definition of this accords also with the rest; for it is evident, that it will be synonymous with the rest. If, indeed, it were not, there will be many definitions of the remaining things that are signified; for there are two definitions adapted to the name, which accord with them; viz. the prior and posterior assigned definitions. Again, if some one having defined one of those things which are multifariously predicated. and the definition not being adapted to all of them, should not, indeed, say that it is homonymous, but should deny that the name is common to all of them, because the definition is not adapted to them; against such a one it must be said, that it is requisite to use that appellation which is delivered and received, and that things of this kind are not to be moved. Some things, however, must not be asserted in a way similar to the multitude.

Aristotle, Topics. Book VI, Chapter 11

But if the definition of some one of those things which are connected should be given, it must be considered by taking away the definition of one of the things connected, whether the remaining definition is the definition of that which remains. For if not, it is evident, that neither will the whole be the definition of the whole. Thus, if some one should define a finite right line to be the boundary of a  superficies which has boundaries, of which the middle darkens the extremities; if the definition of a finite line is, the boundary of a superficies which has boundaries, it is necessary, that what remains should be the definition of a right line, of which the middle darkens the extremities. An infinite right line, however, has neither middle, nor extremes, and yet it is a right line; so that what remains will not be the definition of what remains. Farther stiil, it must be considered, if when that which is defined is a composite, the assigned definition consists of as many members as the thing defined. But a definition is said to consist of an equal number of members, when, as many as are the composites, so many are the nouns and verbs in the definition. For it is necessary, in definitions of this kind, that there should be a commutation of the names, either of all, or of some of them; since no more names are adduced now than before. But it is necessary, that he who defines, should deliver a sentence instead of names, as much as possible, indeed, of all things, but if not, of most things. For thus also, in simple things, he who changes the name, will not define; as, if he should change the name, vestment for garment. Farther still, the error is greater, if by the change names more unknown should be assumed; as, for instance, a white mortal instead of a white man. For there will be no definition; and what is thus said, will be less clear. It must likewise be considered in the  commutation of names, whether the same thing is yet signified; as, he who says, that contemplative science is contemplative opinion. For opinion is not the same with science. It is necessary, however, that it should be the same, if the whole is to be the same. For the word contemplative is common in both definitions; but that which remains is different. Again, it must be considered, whether a change being made of one of the names, a commutation is made, not of difference, but of genus; as, in the instance just now adduced. For the word contemplative is more unknown than the word science; because the one is genus, but the other difference. But genus is more known than all other things; for it is more common. Hence, it is necessary, that a change should be made, not of genus, but of difference; since this is more unknown. Or, may we not say, that this reproof is ridiculous? For nothing hinders, but that difference may be signified by a most known name, and that genus may not. But this being the case, it is evident that a change must be made in the name of genus, and not in the name of difference. If, however, a name is not assumed for a name, but a sentence for a sentence; it is evident, that the definition of difference is to be given, rather than that of genus; since definition is given in order that a thing may become known. For difference is less known than genus.

Aristotle, Topics. Book VI, Chapter 12

If, however, the definition of difference is asigned, it must be considered, whether the assigned definition is common to any thing else. Thus, when it is said that an odd number is a number which has a middle, it must be explained in what manner it has a middle. For the word number is common in both the assertions; but a sentence is assumed instead of the word odd. A line, however, and a body, have a middle, though they are not odd numbers. Hence, this will not be the definition of the odd. But if that which has a middle is multifariously predicated, it must be explained how the middle is possessed. Hence, there will be a reproof, or a syllogism, that the thing is not defined. Again, it must be considered, if that the definition of which is assigned, is in the number of beings; but that which is under the definition is not;  as, if white should be defined to be, colour mingled with fire. For it is impossible that the incorporeal should be mingled with body; so that it will not be colour mingled with fire; but it is white. Farther still, those who in defining things which are relatives, do not distinctly explain that to which they are referred, but embrace many things, speak falsely, either wholly, or in part; as, if some one should say, that medicine is the science of being. For if medicine is the science of nothing which exists, it is evident, that the definition is wholly false; but if it is the science of something that exists, and of something which exists is not the science, the definition will be partly false. For it is necessary, that it should be the science of every thing, if it is said to be the science of being, per se, and not from accident; as is the case in other things which are relatives. For every object of science, is referred to science. And in a similar manner in other things; since all relatives reciprocate. For every thing which is an object of science is a relative. Again, if he who explains a thing, not per se, but from accident, rightly explains it, each of the things which are relatives, will not be referred to one thing, but to many things. For nothing hinders, but that one and the same thing may be both white and good; so that he who explains, by referring to any one of these, will rightly explain, if he who explains from accident, rightly explains. Again, it is impossible that a definition of this kind, should be the peculiarity of the thing explained; for not only medicine, but many other sciences, are referred to that which exists. Hence, each will be the science of being. It is evident, therefore, that this is the definition of no science; for it is necessary, that definition should be peculiar, and not common. Sometimes, however, they define not merely a thing, but a thing in a good condition, or perfect. But of this kind is the definition of a rhetorician, and of a thief; since, a rhetorician is one who is able to perceive what is capable of persuading in every thing, and who omits nothing; but a thief is one who takes privately. For it is evident, that each being such is good; viz. the one will be a good rhetorician; but the other a good thief. For not he who takes privately, but he who wishes to take privately, is a thief. Again, he will err, who assigns that which is of itself eligible, as, practical, or effective, or in any way eligible on account of something else; as if some one should say, that justice is the preserver of laws, or that wisdom is effective of felicity. For that which is effective or preservative, is among the number of things eligible on account of something else. Or, shall we say, that nothing hinders, but that a thing which is eligible per se, may also be eligible on account of something else? He, however, no less errs, who thus defines that which is eligible per se. For in every thing, that which is the best, especially subsists in the essence of that thing. But it is better to be eligible per se, than on account of something else; so that it is necessary that definition should rather signify this.

Aristotle, Topics. Book VI, Chapter 13

It is likewise requisite to consider, whether he who assigns the definition of a certain thing, defines that it is these things, or that which consists from these things, or this together with that. For if he should say that it is those things, it will happen that it will be present with both and with neither; as, if he should define justice to be temperance and fortitude. For if there are two persons each of which has one of these, both and neither of them will be just; since both of them will have justice, but each of them will not. If, however, this is not yet very absurd, because in other things also a thing of this kind happens; for nothing hinders, when there are two persons, but that both may have a mina, though neither of them has, yet, that contraries should be present with the same things, may appear to be perfectly absurd. But this will happen to be the case, if one of them possesses temperance and timidity, but the other, fortitude and intemperance; for both will have justice and injustice. For if justice is temperance and fortitude; injustice will be timidity and intemperance. In short, such arguments as may be brought to prove, that the parts and the whole are not the same, all these are useful to what has now been said; for he who thus defines, appears to say, that the parts are tbe same with the whole. But the arguments become especially appropriate in those things in which the composition of the parts is manifest, as, in a house, and other things of this kind; for it is evident, that the parts existing, nothing hinders but that the whole may not exist. Hence, the parts are not the same with the whole. But if he should say that the thing defined is not these, but that which consits from these, in the tirst place, it must be considered, whether one certain thing is not naturally adapted to be produced from them. For some things so subsist with reference to each other, that nothing is produced from them; as, a line, and number. In the next place, it must be considered, whether the thing defined is naturally adapted to be inherent in some one first subject; but those things from which he says the thing defined consists, are not naturally adapted to be in some one first subject, but each in the other. For it is evident, that that thing will not consist from these. For in those things in which the parts are inherent, it is also necessary that the whole should be inherent; so that the whole will not be in one first subject, but in many. But if the parts and the whole are in one first subject, it must be considered whether they are not in the same, but the parts in one subject, and the whole in another. Again, it must be considered whether the parts are corrupted together with the whole. For it is necessary it should happen vice versa, that the parts being corrupted, the whole should perish; but the whole being corrupted, it is not necessary that the parts should be corrupted. Or, whether the whole is good or evil, but the parts neither; or vice versa, the parts, indeed, are good or evil; but the whole is neither. For neither is it possible, that a certain good or evil should be produeed from neither, nor that neither should be produced from good or evil. Or, it must he considered, whether the one is more good, than the other is evil; but that which consists from these, is not more good than evil; as, if impudence should be said to consist from fortitude and false opinion. For fortitude is more a good, than false opinion is an evil. Hence, it is necessary, that that which consists from these, should be consequent to the more, and should either be simply good, or more good than evil. Or, shall we say, that this, indeed, is not necessary, unless each is per se good or evil? For many effective things are not of themselves good, but when mingled with certain things, become good. with respect to others, on the contrary, each of them is good; but when mingled, that which is produced is either evil, or neither good nor evil. What is now said, however, is especially apparent in things salubrious and noxious. For some medicines are of such a nature,that each is good; but if both are given mingled together, they are bad. Again, it must be considered, whether any thing is said to consist  from the better and the worse, of which the whole is not worse than the better, but is better than the worse. Or, shall we say, that neither is this necessary, unless those things from which the whole  consists, are of themselves good? For in things which are not of themselves good, nothing hinders but that the whole may not be good, as is evident in things which have been just now mentioned. Again, it must be considered, whether the whole is synonymous with the other part. For it ought not; as neither is it in syllables; for a syllable is synonymous with no one of the elements from which it consists. Farther still, it must be considered, whether the mode of composition is not explained; for to say that a thing consists from these, is not sufficient to a knowledge of the thing; because not merely to consist from these, but
thus to consist from these, is the essence of every composite thing; as is evident in a house. For the composition of these, in any manner whatever, does not produce a house. But if this thing together with that is assigned; in the first place, it must be said, that this thing is assigned together with that, because it is this and that, or because this thing is from those. For he who says, honey together with water, either says, honey and water, or that which consists from honey and water. Hence, whichever of these confesses that this thing is the same with that; the same things may be aptly said, as were before urged against each of these. Again, it must be distinguished in how many ways one thing is said to be with another, and it must be considered, whether this thing is in no respect with that. Thus, if it should be said, that one thing is with another, either as in one and the same subject, as, justice and fortitude are in the soul, or in the same place, or in the same time; but that which is asserted in these, should be by no means true; it is evident, that the assigned definition will not be the definition of any thing, because this thing is by no means with that. But if a distinction being made, in how many ways one thing is said to be with another, it should be true that each is in the same time; it must be considered, whether it is possible that each may not be referred to the same thing; as, if some one should define fortitude to be audacity in conjunction with right conception. For some one may have the audacity to defraud, but a right conception about things salubrious; but he is not yet a brave man, who has this together with that in the same time. Again, he is not a brave man, though both should be referred to the same thing, as, to medical things; for nothing hinders but that some one may possess both audacity and a right conception about medical concerns; at the same time he is not a brave man, who has this together with that. For neither ought each of them to be referred to different things, nor to any casual same thing, but to the end of fortitude; as, to warlike dangers, or if there is any thing else which is more the end than this. Some of the things, however, which are thus explained, by no means fall under the above-mentioned division; as, if anger is pain, in conjunction with an opinion of being despised. For this manifests that pain is produced in consequence of an opinion of this kind. But that something should be produced on account of this, is not the same as for this thing to be in conjunction with that, according to any of the before-mentioned modes.

Aristotle, Topics. Book VI, Chapter 14

Again, if it should be said, that the whole is the composition of these; as, that animal is the composition of soul and body; in the first place, it must be considered, whether the quality of the composition is not mentioned; as, if some one defining flesh or bone, should say, that it is the composition of fire, and earth, and air. For it is not sufficient to say, that it is a composition, but it must also be defined what kind of composition it is. For flesh is not produced from the composition of these, in any way whatever; but from being composed in this way flesh, and in that way, bone is produced. Neither, however, of the things which have been mentioned, appears to be entirely the same with composition. For dissolution is contrary to all composition; but nothing is contrary to any one of the before-mentioned particulars. Farther still, if it is similarly probable, that every or no composite, is composition; but every animal, since it is a composite, is not composition; neither will any other composite be composition. Again, if contraries are naturally adapted to be in a certain thing, and some one should define through one of them alone, it is evident, that he will not define. For otherwise it would happen, that there will be many definitions of the same thing. For what more does he say, who defines through this, than he who defines through the other contrary, since both are similarly adapted to be generated in the same thing? Such, however, is the definition of soul, if it is an essence receptive of science; for it is similarly receptive of ignorance. But if some one is not able to argue against the whole definition, because the whole is not known, he must argue against some one of the parts, if it should be known, and should not appear to be well assigned. For the part being subverted, the whole definition also is subverted. It is likewise necessary, by correcting and reforming such definitions as are obscure, in order to render something manifest, and to be supplied with arguments, thus to make them the object of consideration. For it is necessary, that he who answers, should either admit that which is assumed by him who interrogates, or himself unfold, what that is which is signified by the definition. Farther still, as in assemblies it is usual to introduce a law; and if that which is introduced is better, to abrogate the former law; thus also in definitions, the same method must be adopted, and another definition must be introduced. For if this definition should appear to be better, and to manifest in a greater degree the thing defined, it is evident, that the definition which was before given, will be subverted, since there are not many definitions of the same thing. It is not, however, the least element against all definitions, if some one sagaciously defines with himself the thing proposed, or repeats a definition which has been well framed. For it is necessary, running as it were to an exemplar, to survey what is deficient in the definition, and what is added superfluously; so as to he supplied with a greater number of arguments. And thus much concerning things which pertain to definitions.

Aristotle, Topics. Book VII, Chapter 1

Book VII, Chapter 01 | 02 | 03 | 04 | 05

We must now, however, show, whether that which is the subject of discussion is the same or different, according to the most proper of the before-mentioned modes about the same thing. But it was said, that a thing is most properly the same, which is one in number. A survey must also be made from cases, from things coordinate, and from opposites. For if justice is the same with fortitude, a just man is also the same with a brave man; and that which is done justly, is with that which is done courageously. In a similar manner also in opposites. For if these are the same, the opposites to these also are the same, according to any one of the before-mentioned modes of opposition. For it is of no consequence whether an opposite to this or to that is assumed; since they are the same. Again, a survey must also be made from things which are effective and corruptive, and also from generations and corruptions, and, in short, from things which similarly subsist with reference to either. For of those things which are simply the same, the generations and corruptions are the same, and also things effective and corruptive. It must also be considered among
those things, one of which is especially said to be a certain thing, whether another of them also is especially predicated according to the same thing; as Xenocrates shows that a happy and a worthy life are the same; because a happy and worthy life are the most eligible of all lives; for that is one thing, which is the most eligible, and the greatest. The like also takes place in other things of the same kind. But it is necessary that each of those things which are said to be the greatest, or the most eligible, should be one in number; for otherwise, it will not be demonstrated that it is the same. For it is not necessary if the Peloponnesians and Lacedaemonians, are the bravest of the Greeks, that the Peloponnesians should be the same with the Lacedaemonians; since a Peloponnesian and a Lacedrernonian are not one in number. But it is necessary that the one should be contained under the other, in the same manner as the Lacedaemonians under the Peloponnesians; for if not, it would happen that they are better than each other, if the one is not comprehended under the other. Thus, it is necessary that the Peloponnesians should be better than the Lacedaemonians, if the one is not comprehended under the other; for they are better than all the other Greeks; and in a similar manner it is necessary, that the Lacedaemonians should be better than the Peloponnesians; for they also are better than the rest of the Greeks. Hence, they will be better than each other. It is evident, therefore, that what is said to be the best and the greatest, ought to be one in number, in order to demonstrate that it is the same. Hence, Xenocrates does not demonstrate; for a happy and a worthy life, are  not one in number; so that it is not necessary they should be the same, because both are most eligible; but that one should be under the other. Again, it must. be considered, whether one of those things which are proposed is the same as a certain third thing, or whether also another is the same with it. For if both are not the same with it, it is evident that they are not the same with each other. Farther still, survey must be made, from things accidental to these, and from those things to which these are accidents. For it is necessary that such things as happen to one of them, should also happen to the other; and to those things to which one of them happens, it is also necessary that the other should happen. But if any thing of these is discordant, it is evident that they are not the same. It is likewise requisite to see, whether both are not in one genus of category; but the one manifests quality, and the other quantity, or relation. Again, it must be considered whether the genus of each is not the same; but the one is good, and the other evil; or the one is virtue, and the other science. Or whether the genus is, indeed, the same, but not the same differences are predicated of each; but of the one, the predication is, that it is contemplative science, and of the other, that it is practical science. And in a similar manner in other things. Again, it must be considered from the more if the one receives intension, but the other does not; or if both, indeed, receive it, yet not at the same time. Thus, he who loves in a greater degree, does not in a greater degree desire coition; so that love and the desire of coition are not the same. Farther still, a survey must be made from addition, whether, if each is added to the same thing, it will not make the whole to be the same. Or whether, if the same thing is taken away from each, that which remains is different; as if some one should say, that the double of the half, and the multiple of the half, are the same. For the half being taken away from each, what remains ought to signify the same thing. It does not, however; for the double and the multiple do not manifest the same thing. But it is requisite to consider, not only whether any thing impossible now happens on account of the thesis, but also whether it is possible to be, from the hypothesis; as happens to those who assert that a vacuum, and a plenum of air, are the same. For it is evident, that if the air should depart, there will be a vacuum not in a less, but in a greater degree, but there will no longer be a plenum of air. Hence, a certain thing being supposed, whether false or true, (for it is of no consequence) one of them is subverted, but the other is not. Hence, they are not the same. In short, from those things which are in any respect predicated of each, and of which these are predicated, it must be considered, whether they are in any respect discordant. For such things as are predicated of the one, ought also to be predicated of the other; and of those things of which the one is predicated, it is also necessary that the other should be predicated. Again, since the same thing is predicated multifariously, it must be considered whether; after a certain other manner they are the same. For it is not necessary that those things which are the same in species or genus, should be the same in number. But we must consider whether they are in this way the same, or not in this way. Again, it must be considered whether it is possible that the one can be without the other. So many, therefore, are the places pertaining to the same thing.

Aristotle, Topics. Book VII, Chapter 2

It is evident, however, from what has been said, that all places pertaining to the same thing, which are of a subversive nature, are also useful to definition, as was before observed. For if the name and the definition do not manifest the same thing, it is evident that what is asserted will not be a definition. But no one of those places which have a power of confirming, is useful to definition. For it is not sufficient to show, that what is under definition and name is the same thing, in order to the confirmation of definition; but it is necessary that definition should have every thing else which has been mentioned. After this manner, therefore, and through these things, definition must always be attempted to be subverted.

Aristotle, Topics. Book VII, Chapter 3

If, however, we wish to confirm, in the first place, it is necessary to know, that no one, or but few of those who dispute, syllogize definition, but all of them assume a thing of this kind as a principle; as, for instance, those who are conversant with geometry, and numbers, and other disciplines of this kind. In the next place, it is requisite to know, that it is the business of another treatise to assign accurately what definition is, and in what manner it is necessary to define. Now, however, thus much only must be observed as sufficient for our purpose, that it is possible there may be a syllogism of definition, and of the very nature of a thing. For if definition is a sentence, manifesting the very nature of a thing, and it is necessary that those things which are predicated in the definition, should also be alone predicated in answer to the question what a thing is; (but genera and differences are predicated in answer to this question), it is evident, that if any one assumes those things, which are only predicated of a thing in answer to the question what it is, the sentence which contains these will evidently be a definition. For it is not possible that there can be another definition of the thing, since nothing else is predicated of the thing in answer to the question what it is. It is evident, therefore, that there may be a syllogism of definition. But what the particulars are from which it ought to be constructed, has been determined more accurately, in other treatises. These places, however, are useful to the proposed method. For in contraries and other opposites, whole sentences must be considered, and they must be surveyed according to parts. For if an opposite sentence is the definition of an opposite thing, it is necessary that what is said should be the definition of the thing proposed. But because there are many connexions of contraries, that definition which may especially appear to be contrary, must be assumed from contraries. Whole sentences, therefore, as we have said, must be considered. But according to parts, as follows: In the first place, it is shown, that the assigned genus is rightly assigned. For if a contrary is in a contrary genus; but the thing proposed is not in the same genus; it is evident, that it will be in a contrary genus; since it is necessary that contraries should either be in the same genus, or in contrary genera. We also think, that contrary differences are predicated of contraries, as of black and white; for the former has the power of separating,
but the latter of collecting the sight. Hence, if contrary differences are predicated of a contrary, the assigned differences will be predicated of the thing proposed. Hence, since both genus and differences are rightly assigned, it is evident, that the thing assigned will be a definition. Or, shall we say, it is not necessary that contrary differences should be predicated of contraries, unless they should be contraries in the same genus? But of those things of which the genera are contrary, nothing hinders but that the same difference may be predicated of both; as of justice, and injustice. For the one is a virtue, but the other a vice, of the soul. Hence, the word soul, which is difference, is predicated of both; since there is also a virtue and vice of the body. This, however, is true, that of contraries there are either contrary, or the same differences. If, therefore, a contrary difference is predicated of a contrary, but not of this, it is evident, that the difference which is adduced, will be predicated of this. And, in short, since definition consists from genus and differences, if the definition of a contrary thing is manifest, the definition also of the proposed thing will be manifest. For since that which is contrary is either in the same, or in a contrary genus; and in a similar manner, either contrary, or differences are predicated of contraries; it is evident, that either the same genus will be predicated of the thing proposed, which was predicated of the contrary; but the differences are contrary either all, or some of them, and those which remain are the same; or, on the
contrary, the differences are the same, but the genera are contrary; or both genera and differences are contrary. For it is not possible that both can be the same, since, otherwise, there will be the same definition of contraries. Farther still, arguments must be derived from cases and things co-ordinate. For it is necessary that genera should be consequent to genera, and definitions to definitions. Thus, if oblivion is the rejection of science; to become oblivious, will be to reject science; and to have forgotten will be, to have rejected science. One, therefore, of the before-mentioned particulars being conceded, it is necessary that the rest also should be conceded. In a similar manner, likewise, if corruption is a dissolution of essence; to be corrupted will be, for essence to be dissolved; and that which is corruptive will also have a dissolving power. And if that which is corruptive has a power of dissolving essence; corruption also will be a dissolution of essence. And in a similar manner in other things. Hence, any one being assumed, all the rest likewise will be conceded. Arguments also may be derived from things which subsist similarly with reference to each other. For if that which is salubrious is productive of health; that also which has the power of causing a good condition of body, will be productive of a good condition of body; and that which is beneficial, will be productive of good. For each of the above-mentioned particulars subsists similarly vvith respect to its proper end. Hence, if the definition of one of them is, to be effective of the end; this will also be the definition of each of the rest. Again, arguments may be derived from the more and the similar, in as many ways as it is possible to confirm, two things being compared with two. Thus, if this thing is more the definition of that, than something else of another thing; but that which less appears to be, is a definition; that also which more appears to be, will be a definition. And if this is similarly the definition of that, and another thing of something else; if the one is the definition of the other; that which remains, will also be the definition of that which remains. But when one definition is compared with two things or two definitions with one thing, the consideration from the more will afford no utility. For neither can there he one definition of two things, nor two definitions of the same thing.

Aristotle, Topics. Book VII, Chapter 4

Those places, however, which have been now mentioned, and also those from cases and things coordinate, are the most appropriate of all others. Hence, it is especially necessary to remember these, and to have them at hand; for they are most useful to most problems, and of the rest, those which are especially common; for these are the most efficacious of those which remain; such, for instance, as, to look to particulars, and to consider in species, whether the definition is adapted to them, since species is synonymous. But this place is useful against those who assert that there are ideas, as was before observed. Farther still, it must be considered, whether a name is introduced metaphorically; or whether the same thing is predicated of itself as different. And if there is any other place common and efficacious, it must be employed.

Aristotle, Topics. Book VII, Chapter 5

But it win be evident, from what will in the next place he said, that it is tnore difficult to confirm, than to subvert definition. For it is not easy for him who interrogates,to see and to receive from those who are interrogated propositions of this kind; as, that of the things contained in the assigned definition, one is genus, but another difference; and and that in answer to the question what a thing is, genus and differences only are predicated. But without these it is impossible that there should be a syllogism of definition, For if certain other things also are predicated of a thing in answer to the question what it is; it is immanifest whether what is mentioned, or something else, is the definition of it, since definition is a sentence signifying what the very nature of a thing is. This, however, is evident, from what follows. For it is more easy to conclude one than many things. And to him who subverts, indeed, it is sufficient to dispute against one part of the definition; for by subverting any one part whatever, we shall subvert the definition. But it is necessary that he who confirms, should prove that every thing is inherent which is posited in the definition. Again, a universal syllogism must be adduced by him who confirms. For it is necessary, that of every thing of which a name is predicated, definition also should be predicated; and besides this, vice versa, that a name should be predicated, of that of which definition is predicated, if the intended definition is to be proper. It is not, however, necessary that he who subverts should demonstrate that which is universal; for it is sufficient to show that the definition is not verified of any one of the things contained under the name. And if it should be requisite to subvert universally, neither then is  reciprocation in subverting necessary; for it is sufficient for him who subverts universally to show, that the definition is not predicated of some one of those things of which the name is predicated. On the contrary, it is not necessary to show, that neither is the name predicated of those things of which the definition is not predicated. Farther still, if it should be present with every thing which is contained under the name, yet not alone, the definition will be subverted. The like also takes place, with respect to peculiarity and genus; for in both, it is easier to subvert than to confirm. Concerning peculiarity, indeed, this will be evident, from what has been said; since, for.the most part, peculiarity is assigned in the conjunction of words. Hence, it is possible to subvert by taking away one word; but it is necessary that he who confirms should syllogistically conclude every thing. Nearly, however, every thing else which pertains to definition, may also be adapted to peculiarity. For he who confirms ought to show that the definition accords with every thing, which is contained under the name; but it is sufficient for him who subverts to show that it does not accord with one thing. If, however, it accords with every thing, but not alone, thus also it will be subverted, as was observed in definition. Concerning genus also it is evident, because it is necessarily confirmed in one way only, if it is shown to be present with every individual. But it is subverted in a twofold respect. For whether it is shown to be present with no individual, or not to be present with a certain individual, that which was posited as genus in the beginning will be subverted. Again, it is not sufficient for him who confirms to prove that it is inherent, but it must be shown that it is, inherent as genus. But for him who subverts, it is sufficient to show that it is not inherent either with a certain, or with no individual. It seems, however, that as in other things it is easier to corrupt than to produce, so in these to subvert is easier than to confirm or contract. But with respect to acciqent, it is more easy to subvert than to construct that which is universal. For by him who confirms, it must be shown that it is present with every individual; but by him who subverts, it is sufficient, that it is not present with one individual. On the contrary, it is easier to confirm than to subvert that which is partial. For to him who confirms, it is sufficient to show that it is present with a certain individual; but by him who subverts, it must be shown that it is present with no individual. It is likewise evident, why it is the easiest of all things to subvert definition; for since many things are asserted in definition, many things also are given, by which it may be subverted. But from many things, a syllogism is more swiftly formed; for it is more likely that error should be produced in, many than in few things. Farther still, from other things also, it is possible to argue for the purpose of subverting definition. For ,whether what is asserted is not peculiar, or whether that which is assigned is not genus, or whether some one of the things posited in the definition is not present, the definition will be subverted. But for the purpose of subverting other things, neither those arguments which are derived from definitions, nor all the other arguments, can be assumed; for those only which pertain to accident, are common to all the particulars which have been mentioned; since it is necessary that each of the above-mentioned particulars should be inherent. If, however, genus is not inherent as peculiarity, genus will not yet be subverted. In a similar manner, it is not necessary, that peculiarity should be inherent as genus; nor that accident should be inherent as genus, or as peculiarity, but only that it should be inherent. IIence, it is not possible to argue from some things to others, unless in definition. It is evident, therefore, that it is the easiest of all things to subvert definition. But it is most difficult to construct or confirm it; for it is necessary that all those particulars should be syllogistically inferred; viz. that all the before-mentioned particulars are inherent, that what is assigned is genus, and that what is asserted is peculiar, and besides this, it must be shown that what is asserted manifests the very nature of a thing, and it is necessary that this should be done well. Among other things, however, peculiarity is especially a thing of this kind. For it is more easy to subvert it, because it for the most part consists from many things. But it is most difficult to confirm it; because it is necessary to bring together many things, and besides this, to prove that it is inherent, and reciprocates with a thing. It is the most easy of all things, however, to confirm accident. For in other things, not only the being inherent, but the being thus inherent, must be shown; but in accident, it is alone sufficient to show that it is inherent. But it is most difficult to subvert accident, because the fewest things are given in it; for, in addition to other things, the manner of being inherent is not signified accident. Hence, in other things it is possible to subvert in a twofold respect, either by showing that they are not inherent, or that they are not thus inherent; but in accident, it is not possible to subvert, unless it is shown that it is not inherent. The places, therefore, through which we may abound with arguments against the several problems, have nearly been sufficiently enumerated.

Aristotle, Topics. Book VIII, Chapter 1

Book VIII, Chapter 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14

In the next place, we must speak about fhe order of arguments, and in what manner it is necessary to interrogate. First, then, it is necessary, that he who intends to interrogate, should find a place whence he may argue. Secondly, he should interrogate, and arrange every thing by himself. And in the third and last place, he should assert these things to another person. As far as concerns, indeed, the invention of the place, the consideration of it similarly pertains to the philosopher; and to him who is skilled in dialectic. But now to arrange these, and to interrogate, is the peculiarity of him who is skilled in dialectic; for the whole of this is with reference to another person. But to the philosopher, and to him who investigates by himself, it is of no consequence, if the particulars through which the syllogism is constructed, are true and known, whether he who answers, admits them or not, because they are near to the question proposed from the first, and they foresee what will happen. Perhaps too, they earnestly endeavour that axioms may be especially known and proximate to the problem; for scientific syllogisms consist from these. We have already, therefore, shown, what the places are whence arguments ought to be derived; but we must now speak concerning arrangement and interrogation, having distinguished those propositions which are to be assumed, besides such as are necessary. But those are said to be necessary through which a syllogism is formed. And those which are assumed besides these, are four. For they are either assumed for the sake of induction, that universal may be conceded, or for the purpose of amplifying what is said, or in order to conceal the conclusion, or that what is said, may become more perspicuous. No proposition, however, is to be assumed besides these, but we must endeavour, either through these, to increase what is said, or to interrogate. But those which are for the purpose of concealment, are to be assumed for the sake of contention. Since, however, the whole of this treatise has reference to another person, it is necessary to use these propositions. The necessary propositions, therefore, through which a syllogism is formed, must not be immediately proposed, but we must recede to that which is highest. Thus, we must not require it to be granted, that there is the same science of contraries, if we wish to assume this, but that there is the same science of opposites; for this being posited, it may be syllogistically inferred that there is the some science of contraries; since contraries are among the number of opposites. But if the opponent does not admit this, it must be assumed through induction, contraries being severally proposed. For the necessary propositions must be assumed, either through syllogism, or through induction; or some must be assumed through induction, and others through syllogism. But such as are very perspicuous, we should propose immediately. For that which will happen, is always more obscure receding and induction. And, at the same time, it is easy for him to propose those which are useful, who cannot assume them in that way. Those, however, which have been enumerated besides these, are to be assumed for the sake of these; but each is to be used as follows: He who makes an induction should proceed from particulars to universals, and from things known to such as are unknown. But those things are more known which are according to sense, either simply, or to the multitude. He, however, who conceals must, through prosyllogisms, prove those numerous things through which there will be a syllogism of that which was proposed from the first. And this will be effected if some one not only syllogistically collects necessary propositions, but some proposition from among these, which is useful to these. Again, the conclusions must not be mentioned, but afterwards, a sudden conclusion must be made. For thus, he will in the greatest degree recede from the thesis proposed at first. In short, it is necessary that he who is interrogated secretly, should so interrogate, that when an interrogation has been made to the whole of what was asserted, and the conclusion is announced, it may be enquired why it is so. But this will be especially effected, through the before-mentioned mode. For if the last conclusion alone should be mentioned, it will be immanifest how it was collected, because he who answers did not foresee from what it would be collected, the former syllogisms not being distinctly divided. But the syllogism of the conclusion will be in the smallest degree distinctly divided, when its lemmas are not posited by us, but those things from which the syllogism is formed. It will also be useful to assume the axioms from which the syllogisms are produced, not in continuity, but to mingle them alternately with the conclusions. For when those that are appropriate are placed by each other, that which results from them will be more apparent. It is likewise requisite to assume in the definition, as much as possible, a universal proposition, not in the things themselves which are the subjects of discussion, but in those which are co-ordinate. For those who answer deceive themselves by a paralogism, when the definition is assumed in that which is co-ordinate, as if they did not concede what is universal; as, if it should be requisite to assume that he who is angry aspires after vengeance, and anger should be assumed to be the appetite of vengeance, arising from apparent contempt. For it is evident, that this being assumed, we shall have the universal, which is the object of our choice. But when the definition is proposed in those very things which are the subject of discussion, it frequently happens that he who answers rejects it, because he has the objection more prepared in the subject of discussion; as, that not every one who is angry aspires after vengeance; because we are angry, indeed, with our parents, but we do not in our anger aspire after vengeance. Perhaps, therefore, this objection is not true; for in some things, to give pain alone, and produce repentance, is sufficient vengeance. It has, nevertheless, something persuasive, in order that the thing proposed may not appear to be irrationally denied. But it is not similarly easy to find an objection against the definition of anger. Again, it is necessary so to propose, as if we did not propose on account of that which is the subject of discussion, but for the sake of something else. For those who answer are cautious of those things which are useful against the thesis. In short, he who interrogates ought as much as possible to make it immanifest, whether he wishes to assume the thing proposed, or the opposite. For that which is useful against the thesis being obscure, they will the more readily adopt that which appears to them to be true. Farther still, it is necessary to interrogate through similitude. For it has a power of persuading, and is more latent than universal; as, for instance, that as there is the same science and ignorance of contraries, so likewise there is the same sense of contraries. But this is similar to, yet is not the same with induction. For there universal is assumed from particulars; but in similars, that wbich is assumed is not universal, under which all the similars are contained. It is likewise necessary that he should sometimes object to himself; for those who answer to, do not suspect such as appear to argue justly. But it is also useful to say, in addition to this, that what is proposed, is a thing usually asserted; for they will be unwilling to change what is useful, unless they have an objection. And at the same time, because they themselves use things of this kind, they will be careful not to change them. Again, it is requisite not to be earnest in asserting any thing though the thing itself should be useful; for to those who are earnest, greater opposition is made. It is also requisite to propose as by comparison. For that which is proposed on account of something else, and is not of itself useful, will be more readily admitted. Farther still, that must not be proposed which ought to be assumed, but that to which this is necessarily consequent; for it will be more readily granted, because that which may be collected from these, is not similarly manifest; and this being assumed, thatn also will be assumed. And in the last place, he who interrogates should ask that, which he especially wishes to assume. For (those who answer] will especially at first deny, because most of those who interrogate, first assert those things about which they are most earnest. But against some, things of this kind must be first proposed. For those who arc difficult to be persuaded, especially, at first, concede, if the result is not perfectly apparent; but at last, they assent with difficulty. Those likewise act in a similar manner, who fancy themselves acute in answering; for admitting many things, they at last employ fallacious arguments, as, if the conclusion did not follow from the things which were posited; but they concede, readily trusting to habit, and apprehending that they shall suffer no inconvenience. Again, it is requisite to extend the discourse, and to insert things which are not useful to it, as those do who write falsely. For, as there are many things, it is irnmanifest, in which of them the falsity consists. Hence, sometimes those who interrogate are latent, proposing occultly, those things which when proposed by themselves, would not be admitted. For the purpose of concealment, therefore, the things which have been mentioned must be used; but for the purpose of ornament, induction, and division of things of a kindred nature, must be employed. With respect to induction, therefore, what kind of thing it is, is evident. But division is a thing of such a kindas, that one science is better than another, either because it is more accurate, or because it pertains to more excellent objects; and that of the sciences, some are contemplative, others practic, and others effective. For every thing of this kind gives ornament to a discourse, and it is not necessary that it should be adduced for the purpose of producing the conclusion. But, for the sake of perspicuity, examples and comparisons must be introduced. The examples, however, must be appropriate, and from which we may derive information, such as Homer, and not such as Choerilus proposes. For thus, that which is proposed will be more perspicuous.

Aristotle, Topics. Book VIII, Chapter 2

In disputing, however, syllogism must be used rather with those who are skilled in dialectic, than with the multitude; but, on the contrary, with the multitude, induction must rather be used. Concerning these things, however, we have spoken before. But in certain things, he who makes an induction may interrogate the umversal; and in others this is not easy, because a common name is not posited in all similitudes; but when it is necessary to assume the universal, thus it is, they say, in all such particulars. To define this, however, is among things the most difficult, viz. which of those that are adduced are such, and which are not such. Hence, in disputing, they frequently circumvent each other, some asserting that things which are not similar, are similar; but others doubting that similars are not similars. On this account, in all such particulars he who disputes must endeavour to assign a name; so that it may neither be possible for him who answers; to doubt, as, if that which is adduced, is not similarly asserted, nor for him who interrogates, to calumniate, as if it were simihnly asserted; since many things which are not similarly asserted, appear to be similarly asserted. But when an induction being made in many things, he who answers does not admit the universal, then it is just to demand the objection. He, however, who does not say in what particulars this is the case, does not justly demand in what particulars it is not so. For it is necessary, having first made an induction, thus to demand the objection. But it must be requested that the objections are not adduced in the thing proposed, unless one thing only should be a thing of this kind, as, the duad alone is the first of even numbers. For it is necessary that he who objects, should adduce the objection in another thing, or should say, that this alone is a thing of this kind. With respect, however, to those who object to universal, but do not adduce the objection, in the same genus, but in that which is  homonymous; (as, that some one may have not his own colour, or foot, or hand; for a painter may have not his own colour, and a cook, not,his own foot) in things of this kind, employing division, an  interrogation must be made. For the equivocation being ]atent, it will appear to be well to object to the proposition. But if the objector by objecting, not in the homonymous, but in the same genus, impedes the interrogation, it is necessary, by taking away that in which the objection consists, to propose that which remains, universally, until that which is useful is assumed; as may be understood in oblivion, and to have forgotten. For they do not say, that he who has abandoned science, has forgotten; because the thing failing, he has, indeed, abandoned science, but has not forgotten. That being taken away, therefore, in which the objection consists, what remains must be asserted. Thus, if the thing remaining, he abandons science, it must be said, that he has forgotten. A similar method must be adopted against those who object to this proposition, that a greater evil is opposed to a greater good. For they adduce this objection, that to health, which is a less good than a good habit of body, a greater evil is opposed; since disease is a greater evil than a bad habit of body. In these things, therefore, that must be taken away in which the objection consists; for then, he who answers, will more readily concede, as, that a greater evil is opposed to a greater good, unless one thing co-introduces another, as, a good habit of body co-introduces health. Not only, however, when an objection is made, this must be done, but also, if the proposition should be denied without an objection, in consequence of foreseeing something of this kind. For that being taken away in which the objection consists, the objector will be compelled to assent, in consequence of not foreseeing in that which remains, in what particular thing it is not so; but if he should not assent when heis asked for his objection, he will not be able to give it. Propositions, however, of this kind, are those, which are partly false, and partly true. For in these it is possible, by ablation, to leave that which remains, true. But if, when interrogating he proposes in many things the other person does not object, he must be requested to concede. Fot the proposition is dialectic, against which, thus subsisting in many things, there is not an objection. When, however, the same thing may be syllogistically collected without the impossible, and through the impossible; possible; it is of no consequence with respect to him who does not dispute, but demonstrates, whether he syllogizes in this, or in that way. But he who disputes, must not use a syllogism leading to the impossible; for if he syllogizes without the impossible, it cannot be doubted. When, however, they syllogistically collect the impossible, unless it is very evidently false, they say, it is not impossible; so that those who interrogate, do not obtain what they wish. But it is necessary to propose such particulars as thus subsist, in many things, but the objection either, in short, is not, or cannot easily be perceived. For not being able to see in what particulars it is not so, they concede to that which was proposed, as if it were true. The conclusion, however, ought not to be made a question; for otherwise, he who answers denying, a syllogism does not appear to have been formed. For they frequently deny the conclusion, though the opponent does not interrogate, but forms an inference, as of that which is consequent; and thus acting, they do not appear to confute, to those who do not perceive what happens from the thing:; which were posited. When, therefore, he interrogates, not asserting that the conclusion will follow, but the other denies; a syllogism will entirely not appear to have been formed. Nor does it appear that every universal is a dialectic proposition; as, what is man; or in how many ways is good predicated? For a dialectic proposition is that to which it may be answered, yes, or no; but it is not possible thus to answer to the before-mentioned propositions. Hence, interrogations of this kind are not dialectic, unless he who interrogates speaks by defining or dividing; as, for instance, is good predicated in this, or in that way? For the answer to things of this kind is easy, either by affirming, or denying. Hence, such propositions must be endeavoured to be proposed. And at the same time, it is perhaps just, to ask him who answers, in how many ways good is predicated, when he who interrogates divides and proposes, but he who answers by no means concedes. He, however, who makes one reason the subject of interrogation for a long time, is badly interrogated. For, if he who is interrogated answers the question, it is evident, that he who interrogates asks many, or the same questions frequently; so that he either trifles, or has not a syllogism. For every syllogism consists from a few things. But if the other does not answer the question, why does he not reprove him, or depart?

Aristotle, Topics. Book VIII, Chapter 3

It is, however, difficult to oppose, and easy to maintain the same hypotheses. But things which are first by nature, and those which are last, are things of this kind. For those which are first, require definition, and those which are last, are concluded through many things, by him who wishes to assume a continued series of arguments, from things which are naturally first; since, otherwise, the arguments will appear to be captious. For it is impossible to demonstrate any thing, without beginning from appropriate principles, and proceeding in a continued series of arguments as far as to things which are last. Hence, those who answer, neither think fit to define, nor consider whether he who interrogates should define. Unless, however, it becomes apparent what that is which is proposed, it is not easy to argue. But a thing of this kind especially takes place about principles; for other things are demonstrated through these; but these cannot be demonstrated through other things, but it is necessary that every thing of this kind should become known through definition. Those things also are with difficulty opposed, which are very near to the principle; for it is not possible that many arguments can be adduced against them, since, between them and the principle, there are but few media, through which it is necessary that things posterior to them should be demonstrated. But of all definitions those are the most difficult to oppose, in which such names are employed, that at first it is uncertain, whether they are predicated. Simply, or multifariously; and besides this, it is not known, whether they are predicated properly or metaphorically by him who defines. For, because they are obscure, he is not furnished with arguments; but because he is ignorant whether such things are said metaphorically, he is without reprehension. In short, every problem, when it is with difficulty opposed, must be considered either as requiring definition, or as among the number of things which are predicated multifariously, or metaphorically. Or, it must be considered, as not remote from principles, or that it is difficult because it is not at the first view apparent to us, to which of the before-mentioned modes this very thing is to be referred which is the occasion of the doubt. For the mode being apparent, it is evident, that it will be requisite either to define, or to divide, or to introduce the middle propositions; since the last are demonstrated through these. In many theses also, the definition not being well delivered, it is not easy to discourse and argue; as, whether one thing is contrary to one, or many things. But contraries being properly defined, it is easy to collect, whether there can be many contraries of the same thing or not. The like also takes place in other things which require definition. In the mathematical disciplines likewise, it appears that some things cannot easily be described, through a defect of definition; as, that a line which laterally cuts a superficies, similarly divides both a line and a space. But the definition being given, what is asserted will be evident; for both the spaces and the lines will have a corresponding division. But this is the definition of the same sentence. In short, the first of the elements, when definitions are posited, (as what a line, and what a circle are) are easily demonstrated, except that it is not possible to urge many arguments against each of these, because there are not many media. If, however, the definitions of the principles are not posited, it is difficult, and perhaps entirely impossible, to dispute against them. The like also takes place in things which pertain to disputations. Hence, it is not proper to be ignorant, that when a thesis is with difficulty opposed, it is effected in some one of the above-mentioned modes. When, however, it is more difficult to discuss an axiom and proposition than a thesis, some one may doubt whether things of this kind are to be posited or not. For he who does not admit them, but thinks fit to make this also the subject of discussion, enjoins a greater burden than was posited in the beginning. But if he does admit them, he will believe from things which are less credible. If, therefore, it is necessary not to make the problem more difficult, that axiom must be posited. But if it is requisite to syllogize, through things more known, it must not be posited. Or, shall we say, that it must not be posited by the learner, unless it is more known; but that it must be posited by him who exercises himself in disputation, if only it should appear to be true? Hence, it is evident, that he who interrogates, and he who teaches, ought not similarly to require that something should he posited. What has been said, therefore, is nearly sufficient to show in what manner it is necessary to interrogate and arrange.

Aristotle, Topics. Book VIII, Chapter 4

With respect to answering, however, in the first place, it must be determined what the employment is of him who answers rightly, as also of him who interrogates rightly. But it is the employment of him who mterrogates; so to manage the disputation, as to make him who answers, assert the most incredible things, from those particulars which are necessary on account of the thesis. And it is the employment of him who answers, to take care that the impossible, or the paradoxical, may not appear to happen through him, but on account of the thesis. For it is perhaps another fault, to place that first which is not necessary, and not to preserve that which is posited, in a proper manner.

Aristotle, Topics. Book VIII, Chapter 5

But the particulars are indefinite which are to be observed by those who dispute for the sake of exercise and experiment. For the same scope is not proposed to those who teach or learn, and to those who contend, nor to these, and to those who are always conversant with each other for the sake of enquiry. For those things are always to becposited for the learner which appear to be true; since no one attempts to teach what is false. But of those who contend, it is necessary that the interrogator should entirely appear to do something; and that he who answers, should appear to suffer nothing. It has not, however, yet been distinctly explained by any one, what is to be observed in dialectic associations by those who dispute, not for the sake of contention, but of experiment and enquiry, and to what he who answers ought to direct his attention, and what he should concede, and what not, in order to preserve the thesis well or not well. As, therefore, we have nothing on this subject delivered by others, we shall endeavour to say something ourselves. It is necessary, therefore, that he who answers, should sustain the dispute, a probable or improbable thesis, or neither, being posited; and which is either simply or definitely probable or improbable, as to a certain person, viz. either to him who answers, or to another. But it is of no consequence in whatever way it is probable or improbable; for there will be the same mode of answering well, and of conceding or not conceding that which is interrogated. If, therefore, the thesis is improbable, it is necessary that the conclusion should be probable; but if that is probable, that this should be improbable. For he who interrogates, always concludes the opposite to the thesis. But if that which is posited, is neither improbable nor probable, the conclusion also will be a thing of this kind. Since, however, he who syllogizes properly, demonstrates that which is posited in the question, from things probable and more known; it is evident, that if that which is posited, is simply improbable, he who answers must not concede neither that which does not appear to be simply, nor that which appears, indeed, but appears less than the conclusion. For the thesis being improbable, the conclusion is probable. Hence, it is necessary, that every thing which is assumed, should be probable, and more probable than that which is proposed, in order that what is less known may be concluded through things more known. Hence, unless something of this kind is among the number of things interrogated, it must not be posited by him who answers. But if the thesis is simply probable, it is evident, that the conclusion is simply improbable. Whatever, therefore, appears to be true must be posited, and of those things which do not appear to be true, those must be posited, which are less improbable than the conclusion; for thus it will appear, that the disputation has been conducted with sufficient propriety. A similar method also must be adopted, if the thesis is neither improbable, nor probable. For thus also every thing apparent must be admitted, and of those things which are not apparent, such as are more probable than the conclusion must be conceded. For thus it will happen, that the arguments will be more probable. If, therefore, that which is posited, is simply probable or improbable; a comparison must be made with reference to those things which simply appear to be true. But if that which is posited, is not simply probable or improbable, but to him who answers; it must be posited or not posited, with reference to him who answers, and thus a judgment must be formed of that which appears or does not appear. If, however, he who answers, defends the opinion of another, it is evident, that every thing must be posited and denied, looking to the  conception which he forms. Hence, those who entertain foreign opinions, as, that good and evil are the same, as Heraclitus says do not admit that contraries are not at one and the same time present with the same thing, not because this does not appear to them to be the case, but because this must be asserted, according to Heraclitus. This they also do, who receive theses from each other; for they conjecture what he by whom the thesis is posited, will say. It is evident, therefore, what the particulars are to which he who answers should direct his attention, whether that which is posited is simply probable, or is probable to a certain person.

Aristotle, Topics. Book VIII, Chapter 6

Since, however, it is necessary, that whatever is interrogated should either be probable or improbable, or neither, and should either pertain or should not pertain to the disputation; if, indeed, it is probable, and does not pertain to the disputation, it must be admitted, having previously asserted that it is probable. For this being admitted, that which was posited in the beginning is not subverted. But if it is neither probable, nor pertains to the disputation, it must be admitted, indeed, but it must be signified that it does not appear to be probable to us, for the sake of avoiding fatuity. If, however, it pertains to the disputation, and is probable, it must be said, that it appears, indeed, to be true, but that it is very near to what was proposed in the beginning, and that this being admitted, what was posited is subverted. But if it pertains to the disputation, and the axiom is very improbable, it rnust be said, that this being posited, the conclusion, indeed, is effected, but that what is proposed is very stupid. And if it is neither improbable, nor probable, if, indeed, it does not at all pertain to the disputation, it must be admitted, nothing being defined. But if it pertains to the disputation, it must be signified, that this being posited, what was proposed in the beginning is subverted. For thus, he who answers, will appear to suffer nothing through his own fault, if every thing is posited by him, in consequence of foreseeing what will happen; and he who interrogates, will obtain a syllogism, every thing which is more probable than the conclusion being admitted by him who answers. But it is evident, that those who attempt to syllogize from things more improbable. than the conclusion, do not syllogize well; and, therefore, these things are not to be conceded by those who interrogate.

Aristotle, Topics. Book VIII, Chapter 7

In a similar manner, a reply must be made to things which are obscurely and multifariously asserted. For, since it is granted to him who answers, that if he does not understand, he may say, I do not understand; and if the thing proposed is multifariously predicated, it is not necessary that he should assent to, or deny it; it is evident, that, in the first place, indeed, if what is asserted is not clear, to him who answers, he must not hesitate to say, that he does not understand it. For frequently; from not clearly conceding, a certain difficulty occurs to those who are interrogated. But if that which is multifariously predicated is known; if, indeed, that which is asserted is in all things true or false, it must be simply admitted or denied. And if it is partly false, and partly true, it must be signified, that it is predicated multifariously; and why it is partly false and partly true. For if this distinction is made afterwards, it will be immanifest whether he who answers perceived the ambiguity in the begirming. But if he did not foresee the ambiguity, but made the position, looking to the other thing signified; it must be said against him who leads to the other, that he did not make the position looking to this, but to the other of the things signified. For, since there are many things under the same name or sentence, a doubt easily arises. But if the question which is asked, is clear and simple, the answer to it must be yes, or no.

Aristotle, Topics. Book VIII, Chapter 8

Since, however, every syllogistic proposition, is either some one of those things from which the syllogism is formed, or is assumed for the sake of some one of them; but it is evident, when it is assumed for the sake of one of them, viz. because many things of a similar nature are interrogated; for universal is assumed, for the most part, either through induction, or through similitude, all particulars, indeed, are to be posited, if they are true and probable. But an attempt must be made, to urge an objection against universal. For, to impede the argument without an objection, either real or apparent, is to be morose. He, therefore, who answers, when many things appear to be true, but does not assent to the universal, nor has an objection against it, is evidently morose. Again, if, besides. this, he has not an argument by which he can show, that it is not true, he will in a still greater degree appear to be morose. Neither, however, is this sufficient; for we have many arguments contrary to opinions, which it is difficult to solve; such as is the argument of Zeno, that it is not possible for any thing to be moved, nor to pass through a stadium. Things opposite to these, however, are not on this account to be posited. If, therefore, some one, when he can neither urge a contrary argument, nor object, does not admit what he is asked to admit, it is evident that he is morose. For moroseness, in arguments, is nothing else than an answer foreign from the adduced modes, corruptive of syllogism.

Aristotle, Topics. Book VIII, Chapter 9

But it is necessary so to maintain both the thesis and the definition, that he who answers, may previously argue against himself. For it is evident, that an opposition must be made to those things from which those who interrogate, subvert the proposed problem. Care, however, must be taken, not to maintain an improbable hypothesis. But it may be improbable multifariously. For that hypothesis is improbable, from which it happens that absurdities are asserted; as, if some one should say, that all things are moved, or that nothing is moved. That hypothesis also is improbable, which is chosen by those whose morals are more depraved, and which is contrary to the will; as, that pleasure is good, and that it is better to do an injury then to be injured. For he who makes these assertions is hated, not as maintaining them for the sake of argument, but as asserting what appears to him to be true]

Aristotle, Topics. Book VIII, Chapter 10

Such arguments, however, as syllogistically collect what is false, must be solved, by subverting that from which the false is produced. For it is not solved by the subversion of any thing indiscriminately, not even if if that which is subverted is false. For the argument may contain many falsities; as, if some one should assume, that he who sits, writes, and that Socrates sits; for, from these things it will follow, that Socrates writes. This, therefore, being subverted, that Socrates sits, the argument is not the more solved, though the axiom is false; yet the argument is not on this account false. For if some one happens to sit, indeed, but does not write, the same solution will no longer be adapted to such a one; so that this is not to be subverted, but the assertion that he who sits, writes; since, not every one who sits, writes. He, therefore, entirely solves the argument, who subverts that from which the false is produced. But he knows the solution, who knows that the argument depends on this; as is the case in false descriptions. For it is not sufficient to object, not even if that which is subverted is false; but it must be demonstrated why it is false. For thus, it will be evident, whether he makes the objection, previously looking to something, or not. It is possible, however, to prevent the argument from being conclusive, in a fourfold respect. For if is prevented, either by the subversion of that from which the false is produced; or by urging an objection against him who interrogates. For frequently, though he who answers, does not give a solution, yet he who interrogates, cannot proceed any farther. In the third place, it’ is prevented, by an objection being urged, against the things which arc interrogated. For it may happen, that from the things interrogated, what we wish may not be effected, because the interrogation is improperly made; but something being added, the conclusion may be effected. If, therefore, he who interrogates can proceed no farther, the objection will be against him who interrogates; but if he can, the objection will be against the things interrogated. The fourth, and the worst objection, is that which is referred to time. For some object things of such a kind, as require more time for discussion than the present association admits. Objections,
therefore, as we have said, are produced in a fourfold respect. But of the particulars which have been mentioned, the first only is a solution; for the rest are certain preventions and impediments of the conclusions.

Aristotle, Topics. Book VIII, Chapter 11

But the reprehension of an argument is not the same, when the argument is considered by itself, and when it is the subject of interrogation. For frequently, he who is interrogated, is the cause why the argument is not well managed, because he does not concede things from which he might argue in a proper manner against the thesis; since it does not pertain to the other alone, that the common work is effected in a becoming manner. Sometimes; therefore, it is necessary to argue against him who speaks, and not against the thesis, when he who answers things contrary to him who interrogates, takes an opportunity of calumniating. Hence, they cause the associations to be morose, contentious, and not dialectic. Again, since arguments of this kind, are for the sake of exercise and experiment, and not for the sake of doctrine; it is evident, that not only what is true must be collected, but also what is false; nor always through what is true, but sometimes through what is false. For frequently, what is true being posited, it is necessary that he who disputes, should subvert it; so that false assertions must be proposed. But sometimes, what is false being posited, it must be subverted through false assertions. For nothing hinders, but that to a certain person, things which have no existence may appear to be, rather than things which truly exist; so that, when the argument is assumed from things which appear probable to him, he will rather be persuaded than benefitted. But it is necessary that he who wishes to transfer the reasoning in a proper manner, should argue dialectically, and not contentiously, just as a geometrician argues geometrically, whether that which is concluded is false or true. We have, however, before shown what the nature is of dialectic syllogisms. But since he is a depraved associate who impedes a common work, it is evident that this is also true in arguments. For something common is also proposed in these, except among those who dispute for the sake of exercise. But it is not possible for both these to obtain the same end; since they cannot vanquish more than one. It is, however, of no consequence whether this takes place on account of the answer, or on account of the interrogation. For he who interrogates contentiously, disputes badly; and also, he who does not grant to him who answers what appears to be probable, nor receives whatever he who interrogates wishes to inquire. It is evident, therefore, from what has been said, that the argument is not to be similarly apprehended per se, and him who interrogates. For nothing hinders but that the argument may, indeed, be bad, but that lie who interrogates may as much as possible discourse in the best manner against him who answers. For against those who arc morose, it is not, perhaps, possible immediately to frame such syllogisms as some one may wish, but such as can be framed. Since, however, it is indefinite, when men assume contraries, and when they assume things investigated in the beginning;  for frequently, speaking per se, they assert contraries; and having before denied, they afterwards assent; and hence, when interrogated, they frequently admit contraries, and things which were investigated in the beginning; this being the case, it is necessary that bad arguments should be produced. But he who answers is the cause of this; not, indeed, admitting some things, but admitting these, since these are things of this kind. It is evident, therefore, that those who interrogate, and their arguments, are not to be similarly reprehended. There are five reprehensions, however, per se, of an argument. The first, indeed, is, when from the questions asked, nothing is concluded, neither against the problem which is posited, nor, in short, against any thing; all, or the greatest part of those thingR from which the conclusion is inferred, being either false, or improbable; and, neither certain things being taken away, nor added, nor some being taken away, but others added, the conclusion is effected. The second reprehension is, if a syllogism is not produced against the thesis, from such things, and in such a way, as was beforementioned. The third is, if certain things being added, a syllogism should be formed against the thesis, but these things should be worse than those which are interrogated, and less probable than the conclusion. Again, this will happen, if certain things are taken away. For sometimes those who interrogate assume more than is necessary. Farther still, this will likewise be the case, if the argument is assumed from things more improbable, and less credible, than the conclusion; or if it is assumed from things which are true, but which it is more laborious to demonstrate than the problem. It is not, however, proper to require that the syllogisms of all problems should be similarly probable, and capable of persuading. For immediately some of the things investigated are naturally more easy, and others are more difficult. Hence, he will discourse well who reasons from propositions as much as possible probable. It is evident, therefore, that there is not the same reprehension of an argument, when it is referred to that which was posited in the question, and when it is per se. For nothing hinders but that an argument may be per se reprehensible; but with reference to the problem, laudable; and again, vice versa, that an argument may be per se laudable; but with reforence to the problem blameable, when it is more easy to conclude from many things which are probable and true. For sometimes it is possible, that the argument when conclusive, is worse than that which is not conclusive, viz. when the former concludes from things which are foolish, the problem itself not being such; but the other requires the assumption of such things as are probable and true, and the argument does not consist in the things assumed. It is not just, however, to reprehend those who conclude the true through the false. For it is always necessary that the false should be syllogistically collected through the false; but it is sometimes possible syllogistically to collect the true through the false. But this is evident from the Analytics. When, however, the before-mentioned argument is a demonstration of a certain thing, if there is any thing else which has nothing in common with the conclusion to be proved, there will not be a syllogism from it. But if there should appear to be a syllogism, it will be a sophism, and not a demonstration. A philosophema, however, is a demonstrative syllogism; but an epecheirema, is a dialectic syllogism; a sophism, is a contentious syllogism; and an aporema, is a dialectic syllogism of contradiction. But if any thing should be demonstrated from both the probable propositions, and they are not similarly probable, nothing hinders but that what is demonstrated, may be more probable than each proposition. If, however, the one is probable, but the other is neither probable nor improbable; or if the one is probable, but the other is not; if they are similarly so, the conclusion also will similarly be, and not be. But if one proposition is more probable or improbable, the conclusion will be consequent to that proposition. This also is an error in syllogisms, when any one demonstrates through a greater number of things, what might be demonstrated through a less number, and which are inherent in the argument. As if some one in order to demonstrate that one opinion is more accurate than another, should desire it to be granted, that each thing itself exists in the most eminent degree; but that the object of opinion is truly itself. Hence, it is more than certain other things; but that which is said to be more, is referred to that which is more; and the opinion itself is true, which will be more accurate than certain things. But it was desired to be granted, that opinion itself is true, and that each thing itself exists in the most eminent degree. Hence, this opinion, which is especially true, is more accurate than other things. But what is the fault of this reasoning. May we not say, that it makes the cause to be latent, from which the reasoning is derived?

Aristotle, Topics. Book VIII, Chapter 12

An argument, however, is manifest, in one way, indeed, and that the most popular, if it so concludes, that there is no occasion to interrogate any thing farther. But in another way, and which is said to be especially, when those things are assumed from which that which is concluded necessarily is, but the argument concludes through conclusions. And farther still, if any thing is deficient, but this is very probable. But an argument is denominated false, in a fourfold respect. In one way, indeed, when it appears to conclude, but does not conclude, which is called a contentious syllogism. But in another way, when it concludes something, but which does not pertain to the proposed problem; which especially  happens to those arguments that lead to the impossible. Or, it concludes, indeed, that which pertains to the proposed problem, yet not according to an appropriate method. But this is, if the argument which is not medical should appear to be medical; or that which is not geometrical should appear to be geometrical; or that which is not dialectical, to be dialectical; whether that which is the result is false or true. But in another way, an argument is said to be false if it concludes through false assertions. And of this argument, the conclusion will be sometimes false and sometimes true. For the false, indeed, is always concluded through false assertions; but it is possible that the true may be concluded from assertions which are not true, as we have before observed. That the reasoning, therefore, is false, is rather the fault of hirn who  argues, than of the argument; and neither is it always the fault of him who argues, but when he is ignorant that he said a certain argument was false. For, from among the number of many true assertions, we rather admit that reasoning, which from things which especially appear to be probable, subverts something true. For the reasoning which is such, is a demonstration of true assertions; since it is necessary, that some one of the things which are posited should not entirely be; so that there will be a demonstration of this. But if it should conclude what is true from false and very stupid assertions, it will be worse than many assertions which syllogistically collect the false. Of this kind, however, the reasoning will be which concludes what is false. Hence, it is evident, that the first consideration of the argument per se, will be, whether it concludes. The second will be, whether it concludes the true, or the false. And the third, from what assertions it concludes. For if from those which are false, but probable, it is a logical argument. But if from those which are true, but not probable, it is faulty. And if they are false, and very improbable, it is evident, that the argument is bad, either simply, or with reference to the thing which is discussed.

Aristotle, Topics. Book VIII, Chapter 13

With respect, however, to that which was investigated in the beginning, and contraries, in what manner a postulate should be demanded by him who interrogates, according to truth, indeed, has been shown in the  Analytics, but must now be shown according to opinion. But that which was investigated in the  beginning, appears to be demanded as a postulate in five ways. Most evidently, indeed, and primarily, if any one demands as a postulate, that very thing which ought to be demonstrated. This, however, is not easily latent in the thing itself, but rather in things synonymous, and in such as the name and definition signify the same thing. But, secondly, that appears to be demanded as a postulate when that which ought to be demonstrated according to a part, is universally demanded as a postulate; as, when some one endeavouring to prove that there is one science of contraries, thinks it should be granted him, that there is one science of opposites. For he seems to demand as a postulate, together with many other things, that which it is necessary to demonstrate per se. And, thirdly, if some one, when he proposes to demonstrate what is universal, demands a postulate partially; as if some one, when it is proposed to prove that there is one science of all contraries, should require it to be granted to him, that there is one science of certain contraries. For he also seems to demand as a postulate per se, and separately, that which ought to be demonstrated in conjunction with many things. Again, if some one diyiding a problem should demand as a postulate the thing proposed to be discussed; as if some one when it is necessaty to demonstrate that medicine pertains to the salubrious and insalubrious, should think fit to require each of these to be granted to him separately. Or, if some one should demand as a postulate, one of those things which are necessarily consequent to each other; as, that the side of a square is incommensurate with the diameter, when it is necessary to demonstrate that the diameter is incommensurate with the side. Contraries, however, are demanded as postulates in as many ways as the thing investigated in the beginning. And in the first place, if some one should demand as a postulate, the opposites, affirmation and negation. In the second place, if he should demand as a postulate, contraries according to opposition; as, that good and evil are the same. In the third place, if some one requiring universal as a postulate, should require contradiction to be granted to him partially; as, if assuming that there is one science of contraries, he should desire it to be granted that there is a different science of the salubrious and the insalubrious; or, demanding this as a postulate, should endeavour to assume opposition in the universal assertion. Again, if some one should demand as a postulate, the contrary to that which happens from necessity, through the things posited. Likewise, if some one should not, indeed, assume opposites themselves, but should demand as a postulate two things of that kind from which there will be an opposite contradiction. There is a difference, however, between assuming contraries, and demanding as a postulate what was investigated in the beginning;  because the error of the one pertains to the conclusion; for looking to this, we say, that what was investigated in the beginning, is demanded as a postulate; but contraries are in the propositions, because they subsist in a certain way with reference to each other.

Aristotle, Topics. Book VIII, Chapter 14

In order, however, to the exercise and meditation of such like arguments, in the first place, it is necessary to be accustomed to the conversion of arguments. For thus we shall be more abundantly supplied with what is necessary to the subject of discussion, and we shall obtain a proper knowledge of many arguments in a few particulars. For to convert, is to subvert one of the data, the conclusion being transferred together with the remaining interrogations. For it is necessary, if the conclusion is not that some one of the propositions should be subverted, since it is necessary that all these being posited, the conclusion should be. The argument also must be considered with respect to every thesis, both that it is so, and that it is not so; and this being discovered, the solution must be immediately investigated; for thus it will happen that we shall be exercised both for interrogating and answering. And if we have no other person with whom we can dispute we must dispute by ourselves. A selection of arguments also being made for the purpose of opposition, they must be compared with each other. For this produces a great copiousness for the purpose of compelling assent, and affords great assistance in confutation, when any one is abundantly supplied with arguments on both sides; since, thus it wili happen, that care will be taken to avoid contraries. To be able also to perceive, and to have perceived what will happen from each hypothesis, is no small instrument to knowledge, and philosophic wisdom; for then all that remains is, rightly to choose one ot these. To a thing of this kind, however, a naturally good disposition is requisite; and a naturally good disposition is in reality this, to be able to select, in a proper manner, what is true, and avoid what is false; which those who are naturally good, are able to accomplish well. For those who properly love and hate that which is adduced, will form a judgment of that which is best. It is likewise necessary to know, in a proper manner, the arguments concerning the problems whicb frequently occur in disputation; and especially concerning first theses; for in these, those who answer are frequently indignant. Again, it is necessary to abound with definitions, and to have at hand the definitions of things probable and primary; for through these syllogisms are formed. Those things, likewise, into which disputations frequently fall, must be endeavoured to be possessed. For, as in geometry it is of importance to be exercised about the elements; and in arithmetic to be prompt in the multiplication of numbers in a natural series as far as to ten, contributes greatly to the knowledge of the multiplication of other numbers; thus also, in disputations, to be prompt about principles, and tenaciously retain propositions in the  memory, affords great utility. For as places when only posited in that part of the soul, which remembers, immediately cause them to be remembered; thus, also, these things cause them who dispute to be most syllogistic; in consequence of looking to propositions which are definite in number. A common proposition, likewise, rather than an argument, must he committed to memory. For to abound with principle and hypothesis is moderately difficult. Farther sttll, it is requisite to be accustomed to make one argument to be many, concealing most obscurely. But a thing of this kind will be effected, by very much receding from the alliance of those things which are the subject of discussion. And those arguments which are especially universal, will be able to suffer this; as, that there is not one science of many things; for thus it is in relatives, in contraries, and in things co-ordinate. It is likewise necessary, that universal commentaries should be made of arguments, though the disputation should be partial; for thus it will be possible to make one argument to be many. A similar method must also be adopted in rhetorical enthymemes. But he who disputes, should, as much as possible, avoid universal in introducing syllogisms. It is likewise necessary, always to consider whether the arguments are conversant with things that are common. For all partial arguments are conversant with universal; and the demonstration of universal is inherent in the demonstration which is partial, because nothing can be syllogistically concluded without universal. The exercise also of inductive arguments must be assigned to a young man; but of syllogistic arguments to a skilful man. It is requisite, likewise, to endeavour that propositions may be assumed by those who are skilful in forming syllogisms; but comparisons by those who are skilled in induction; for in these both are exercised. And, in short, from dialectic exercise, it is necesary to  endeavour to refer either a syllogism about a certain thing, or a solution, or a proposition, or an objection; or to observe whether some one rightly interrogates, or not rightly, either himself or another, and after what manner each is effected. For from these the power of dialectic exercise proceeds; and exercise is for the sake of this power, especially in propositions and objections. For he, in short, is skilled in  dialectic, who is prompt in proposing and objecting. But to propose, is to make many things to be one; for it is necessary in the whole to assume that to which the argument is referred. And to object is to make that which is one thing, to be many; for he who objects, either divides, or subverts, partly admitting, and partiy denying the things proposed. It is requisite, however, not to dispute with every one, nor to be exercised against any casual person. For it is necessary, that against some persons bad arguments should be employed. For against him who entirely endeavours to elude the arguments of another, it is just,  indeed, to syllogize, but it is not decorous. Hence, it is not proper readily to engage in disputation with any casual persons; for it is necessary that contumely should be produced from such a conference. For those who exercise themselves dialectically cannot refrain from disputing contentiously. It is likewise requisite to have arguments prepared against those problems, in which the fewest arguments being supplied, we shall have those which are useful against many problems. These, however, are universal arguments, and which are with difficulty supplied from things that are obvious.

THE END

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