But it is not difficult to solve the arguments which oppose what we have said. The following considerations may indeed induce some to think that motion once was, when before it had not any subsistence. First, because no mutation is perpetual: for all mutation is naturally adapted to proceed from something into something; so that it is necessary there should be a boundary of all mutation, viz. the contraries in which it is produced, and that nothing should be moved to infinity. Farther still, we see that a thing may be moved, which neither is moved, nor possesses in itself any motion; as in a thing inanimate, which when neither any part nor the whole of it is moved, but is at rest, is sometimes moved. But it is fit that a thing should either always, or never be moved, if motion is not generated, when it had not any subsistence before. A thing of this kind, however, is much more evident in animated natures. For sometimes when there is no motion in us, but we are at rest, at the same time we are sometimes moved, and the principle of motion is sometimes ingenerated in us, from ourselves, though nothing external moves us. For we do not similarly perceive this in things inanimate, but something else which is external always moves them. But we say that an animal moves itself. So that if at any time the whole is at rest, motion can be produced from itself, in the immoveable, and not externally. If therefore this can be effected in an animal, what should hinder but that it may also happen in the universe? For if it takes place in the microcosm, it may likewise in the great world; and if in the world, also in the infinite, if it be possible for the whole infinite to be moved, and be at rest.
Of these arguments, however, the first, that there is not always one and the same motion in number, which tends to opposites, is rightly asserted. For this perhaps is necessary, if the motion of one and the same thing cannot always be one and the same in number; I say for instance, whether there is one and the same sound of one chord, or always another, when the chord subsists, and is moved similarly. At the same time, however, in whatever manner this may take place, nothing hinders but that there may be some motion which is one and the same, because it is continued and eternal. This however will be more manifest from what will hereafter follow. But there is no absurdity in admitting that a thing may be moved which was not moved before, if that which moves externally is at one time present and at another not. But how this can take place must be investigated. I say then it must take place in such a manner, that the same thing may be at one time moved, and at another not, by the same thing which has the power of moving. For he who says this, doubts nothing else, than why some things are not always at rest, and others in motion. But the third argument may especially appear to be dubious, being that which happens in animated natures, as if motion was ingcnerated in these, when it was not inherent before. For that which was before at rest afterwards walks, nothing external moving. as it appears. This however is false: for we always see something connascent moved in an animal. The animal itself, however, is not the cause of this motion, but perhaps that which surrounds it. But we say, that the animal moves itself, not according to every motion, but that which is according to place. Nothing therefore hinders, but perhaps it is more necessary, that many motions should be generated in the body, by that which surrounds it; that some of these should be produced by the dianoetic power or appetite; and that this should move the whole animal. Just as it happens in sleep: for then no sensitive motion being inherent, though a certain motion is inherent, animals are again excited. These things, however, will be manifest from what follows.
