Since everything which comes to be comes to be either out of something which is or out of something which is not, and it is impossible for both of them to be the case, in that it cannot come to be out of what is (because it is already) nor can it come out of what is not (since it cannot come out of something which is not pre-existent), some people thought either that nothing comes to be or passes away, or that “what is not” is. We, on the other hand, will resolve their difficulty, starting, first, with the various ways in which “what is” is spoken of.
For there is no “what is” without qualification, nor yet is there a common nature of “what is”, but it is spoken of homonymously being predicated of a number of genera; for it indicates either a substance or a quantity or a quality or one of the other types of predicate. For when a man is set out and we say that what is set out is a man or an animal, we say what it is and signify a substance, when that he is musical, we signify a certain qualification and a quality.
What is not
Similarly, nor do “what is not” signify a certain and simple thing, but it stands either for the unqualified “what is not”, namely that which does not exist, or for that which is not something. For just as we say that the man who is musical comes to be out of the man who is unmusical (for the “unmusical” does not mean that which is in no way at all existent but that which is not something), so also with “what is”, out of that which is not in the full sense nothing comes to be, but out of what is not something, comes to be what is something. And this coming-to-be is by virtue of concurrence; for the man who is musical does not come to be in so far as he is unmusical, but as a man; for privation, which in itself is something which is not, is by virtue of concurrence something which is, since it happened to be into the man’s matter. For if something becomes without qualification, clearly it would become out of the unqualified “what is not”, but we assumed that it is something (an unmusical man), and the latter is composite out of matter and form; for everything which is in actuality is of that sort.
So it is clear that that which comes to be does not come to be just by itself as out of that which is not; for the underlying matter becomes part of the actual thing. And of course no absurdity arises, since this does not come to be that which the matter is, but the existing thing is different from the coming-to-be thing.
Moreover, when we say it comes to be out of that which is not, in one sense we mean out of what is not actually, in another out of what is potentially; for the unmusical man is a not-musical man in actuality and a musical man in potentiality. Similarly, too, the bronze becoming a statue, which is its matter, is a bronze in actuality, but a statue in potentiality; for matter, when considered in itself, is never actually but always potentially all the natural kinds. That is why the statue does not come to be the very thing it was, but what it is is different from what is coming to be: the former is the bronze, the latter is the statue.
So what is potentially is not the same as what is actually, and what is in itself is not the same as what is by virtue of concurrence. For one may be potentially and in itself, or potentially and by virtue of concurrence, and similarly one may be actually and in itself, or actually and by virtue of concurrence. For when I say “A doctor is doctoring”, I said as holding actually and in itself, whereas “He will doctor”, as holding potentially and in itself. And again, when I say “A doctor is building”, I said as holding actually and by virtue of concurrence (for he is not building in as far as he is a doctor, but it happened that he is at the same time a builder), whereas “He will build”, as holding potentially and by virtue of concurrence.
These men, then, were diverted into this absurdity by inexperience of the dividing method, considering that “what is” signifies the nature of a particular thing; we ourselves, on the other hand, maintain that “either out of something which is or out of something which is not” is not a contradictory pair; for this is not spoken of in respect of the same thing – but out of something which is, since it is something different, and out of something which is not, since this is not what is coming to be. And thus their difficulty is resolved and no absurdity arises.
Written, translated by George Kotsalis