it is evident that the things are so, although the one should not have affirmed any thing, or the other have denied it, since it is not, because it has been affirmed or denied, that therefore a thing will or will not be, neither will it be more so for ten thousand years than for any time whatever. Hence if a thing so subsisted in every time that one of these is truly asserted of it, it was necessary that this should take place; and each thing generated, always so subsisted, as to have been generated from necessity, for when any one truly said that it will be, it was not possible not to have been generated, and of that which is generated, it was always true to say that it will be.
But if these things are impossible—(for we see that there is a beginning of future things, both from our deliberation and practice, and briefly in things which do not always energize, there is equally a power of being and of not being, in which both to be and not to be occurs, as well as to have been generated and not to have been generated; and, indeed, we have many things which evidently subsist in this manner, for example, it is possible for this garment to have been cut in pieces, and it may not be cut in pieces, but be worn out beforehand, so also it is possible that it may not be cut in pieces, for it would not have been worn out before, unless it had been possible that it might not be cut in pieces, and so also in respect of other productions, which are spoken of according to a power of this kind—) then it is evident that all things neither are, nor are generated of necessity, but that some things subsist casually, and that their affirmation is not more true than their negation, and that there are others in which one of these subsists more frequently, and for the most part, yet so, that either might possibly have occurred, but the other not.
Wherefore, being, must of necessity be when it is, and non-being, not be, when it is not; but it is not necessary that every being should be, nor that non-being should not be, since it is not the same thing for every being
