Return to Aristotle, Categories
1. Of motion there are six Species, viz. Generation, corruption, increase, diminution, variation, and mutation according to place.
2. With respect to the other motions, therefore, it is evident that they are different from each other. For Generation is not corruption; nor is increase diminution, nor mutation according to place; and in a similar manner with respect to other motions.
3. In variation, however, it is doubtful, whether it is necessary that what is changed in quality, is so changed according to some one of the other motions.
4. But this is not true; for it happens that we are changed in quality, nearly according to all the passive qualities, or the greater part of them, without any communication with the other motions. For it is not necessary that what is moved according to passive quality, should be either increased or diminished. And in a similar manner in the other motions. Hence variation will be different from the other motions. For if it were the same, it would be requisite that what is changed in quality, should immediately be also increased or diminished, or follow some one of the other motions; but this is not necessary.
5. In a similar manner also, that which is increased, or moved with any other motion, ought to be changed in quality. Some things, however, are increased, which are not changed in quality. Thus, for instance, a square is increased, when a gnomon is placed about it, but does not become at all more changed in quality. The like also takes place in other things of this kind; so that these motions will be different from each other.
6. Simply, however, rest is contrary to motion; but particular rests to particular motions; corruption, indeed, to Generation; diminution to increase; and the rest according to place, to the mutation according to place. But the mutation according to a contrary place, appears to be especially opposed; as, for instance, ascent to descent, and descent to ascent.
7. It is not, however, easy to assign what is the contrary to that which remains of the motions that have been explained. But it seems that nothing is contrary to it, unless some one should also oppose to this, the rest according to quality, or the mutation of a quality into a contrary quality; just as in the mutation according to place [we oppose] the rest according to place, or the mutation into a contrary place. For variation is a mutation according to quality; so that the rest according to place, or the mutation of a quality into a contrary quality, will be opposed to the motion according to quality. Thus, the becoming white is opposed to the becoming black; for a thing is changed in quality, a mutation of quality into contraries taking place.
Return to Aristotle, Categories
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