“Not-being never is, and do thou keep thy thoughts from this way of enquiry.”
Theaetetus: Yes, he says so.
Stranger: Whereas, we have not only proved that things which are not are, but we have shown what form of being not-being is; for we have shown that the nature of the other is, and is distributed over all things in their relations to one another, and whatever part of the other is contrasted with being, this is precisely what we have ventured to call not-being.
Theaetetus: And surely, Stranger, we were quite right.
Stranger: Let not anyone say, then, that while affirming the opposition of not-being to being, we still assert the being of not-being; for as to whether there is an opposite of being, to that enquiry we have long said goodbye—it may or may not be, and may or may not be capable of definition. But as touching our present account of not-being, let a man either convince us of error, or, so long as he cannot, he too must say, as we are saying, that there is a communion of classes, and that being, and difference or other, traverse all things and mutually interpenetrate, so that the other partakes of being, and by reason of this participation is, and yet is not that of which it partakes, but other, and being other than being, it is clearly a necessity that not-being should be. And again, being, through partaking of the other, becomes a class other than the remaining classes, and being other than all of them, is not each one of them, and is not all the rest, so that undoubtedly there are thousands upon thousands of cases in which being is not, and all other things, whether regarded individually or collectively, in many respects are, and in many respects are not.
Theaetetus: True.
Stranger: And he who is sceptical of this contradiction, must think how he can find something better to say; or if he sees a puzzle, and his pleasure is to drag words this way and that, the argument will prove to him, that he is not making a worthy use of his faculties; for there is no charm in such puzzles, and there is no difficulty in detecting them; but we can tell him of something else the pursuit of which is noble and also difficult.
Theaetetus: What is it?
Stranger: A thing of which I have already spoken;—letting alone these puzzles as involving no difficulty, he should be able to follow and criticize in detail every argument, and when a man says that the same is in a manner other, or that other is the same, to understand and refute him from his own point of view, and in the same respect in which he asserts either of these affections. But to show that somehow and in some sense the same is other, or the other same, or the great small, or the like unlike; and to delight in always bringing forward such contradictions, is no real refutation, but is clearly the newborn babe of someone who is only beginning to approach the problem of being.
Theaetetus: To be sure.
Stranger: For certainly, my friend, the attempt to separate all existences from one another is a barbarism and utterly unworthy of an educated or philosophical mind.
Theaetetus: Why so?
Stranger: The attempt at universal separation is the final annihilation of all reasoning; for only by the union of conceptions with one another do we attain to discourse of reason.
Theaetetus: True.
Stranger: And, observe that we were only just in time in making a resistance to such separatists, and compelling them to admit that one thing mingles with another.
Theaetetus: Why so?
Stranger: Why, that we might be able to assert discourse to be a kind of being; for if we could not, the worst of all consequences would follow; we should have no philosophy. Moreover, the necessity for determining the nature of discourse presses upon us at this moment; if utterly deprived of it, we could no more hold discourse; and deprived of it we should be if we admitted that there was no admixture of natures at all.
Theaetetus: Very true. But I do not understand why at this moment we must determine the nature of discourse.
Stranger: Perhaps you will see more clearly by the help of the following explanation.
Theaetetus: What explanation?
Stranger: Not-being has been acknowledged by us to be one among many classes diffused over all being.
Theaetetus: True.
Stranger: And thence arises the question, whether not-being mingles with opinion and language.
Theaetetus: How so?
Stranger: If not-being has no part in the proposition, then all things must be true; but if not-being has a part, then false opinion and false speech are possible, for to think or to say what is not—is falsehood, which thus arises in the region of thought and in speech.