Metaphysics

Since we have spoken of the potentiality which is spoken of in relation to motion, let us define actuality, what actuality is and what sort of thing it is. For in making this division the potential also will become clear at the same time, because we do not only call that potential which by its nature moves something else or is moved by something else, either without qualification or in a certain way, but also in another way, which is why we also discussed these in our inquiry. Actuality, then, is the existence of a thing not in the way that we say it exists potentially. And we say a thing exists potentially, for instance, a Hermes in the wood and the half-line in the whole, because it could be taken out, and we call someone a knower even when he is not contemplating, if he is capable of contemplating. The other, however, exists in actuality. What we mean to say is clear by induction from the particular cases, and we must not seek a definition of everything but also perceive the analogy, namely that as that which is building is to that which is capable of building, so is that which is awake to that which is asleep, and that which sees to that which has its eyes closed but has sight, and that which has been separated from the matter to the matter, and that which has been finished to that which is unfinished. Of this difference, let actuality be defined by one part, and the potential by the other. But things are said to exist in actuality not all in the same way, but by analogy, as this is in this or in relation to this, so that is in that or in relation to that; for some are as motion to potentiality, and others as substance to some matter. But the infinite and the void, and all such things, are said to exist potentially and in actuality in a different way from many existing things, such as that which sees, that which walks, and that which is seen. For these latter can sometimes be truly said without qualification (for that which is seen is so called because it is seen, and the other because it is capable of being seen); but the infinite does not exist potentially in such a way that it will exist separately in actuality, but only in knowledge. For the fact that division never comes to an end shows that this actuality exists potentially, but not that it exists separately. Since of the actions which have a limit none is an end, but they are of those things related to the end, as for instance slimming or the process of slimming, and these when they are slimming are in motion in this way, the things for the sake of which the motion exists not being present, these are not action, or at least not complete action (for they are not the end); but that action in which the end is present is indeed action. For example, one sees and at the same time has seen, and understands and has understood, and thinks and has thought, but one is not learning and has learned, nor is being cured and has been cured. One lives well and has lived well at the same time, and is happy and has been happy. Otherwise, it would have to stop at some time, just as when one is slimming, but now it does not, but one lives and has lived. Of these, then, we must call some motions and others actualities. For every motion is incomplete, slimming, learning, walking, building; these are indeed motions, and incomplete ones. For one is not walking and has walked at the same time, nor is building and has built, nor is coming to be and has come to be, or is being moved and has been moved, but they are different; and one moves and has moved. But one has seen and sees the same thing at the same time, and thinks and has thought. Now, such a thing I call actuality, and the other motion. What it is to be in actuality, then, and what sort of thing it is, let it be clear to us from these and such considerations.