STRANGER: He who says that falsehood exists has the audacity to assert the being of not-being; for this is implied in the possibility of falsehood. But, my boy, in the days when I was a boy, the great Parmenides protested against this doctrine, and to the end of his life he continued to inculcate the same lesson—always repeating both in verse and out of verse:
'Keep your mind from this way of enquiry, for never will you show that not-being is.'
Such is his testimony, which is confirmed by the very expression when sifted a little. Would you object to begin with the consideration of the words themselves?
...
STRANGER: Let us be serious then, and consider the question neither in strife nor play: suppose that one of the hearers of Parmenides was asked, 'To what is the term "not-being" to be applied?'—do you know what sort of object he would single out in reply, and what answer he would make to the enquirer?
THEAETETUS: That is a difficult question, and one not to be answered at all by a person like myself.
STRANGER: There is at any rate no difficulty in seeing that the predicate 'not-being' is not applicable to any being.
THEAETETUS: None, certainly.
STRANGER: And if not to being, then not to something.
THEAETETUS: Of course not.
STRANGER: It is also plain, that in speaking of something we speak of being, for to speak of an abstract something naked and isolated from all being is impossible.
THEAETETUS: Impossible.
STRANGER: You mean by assenting to imply that he who says something must say some one thing?
THEAETETUS: Yes.
STRANGER: Some in the singular (ti) you would say is the sign of one, some in the dual (tine) of two, some in the plural (tines) of many?
THEAETETUS: Exactly.
STRANGER: Then he who says 'not something' must say absolutely nothing.
THEAETETUS: Most assuredly.
STRANGER: And as we cannot admit that a man speaks and says nothing, he who says 'not-being' does not speak at all.
THEAETETUS: The difficulty of the argument can no further go.
STRANGER: Not yet, my friend, is the time for such a word; for there still remains of all perplexities the first and greatest, touching the very foundation of the matter.
THEAETETUS: What do you mean? Do not be afraid to speak.
STRANGER: To that which is, may be attributed some other thing which is?
THEAETETUS: Certainly.
STRANGER: But can anything which is, be attributed to that which is not?
THEAETETUS: Impossible.
STRANGER: And all number is to be reckoned among things which are?
THEAETETUS: Yes, surely number, if anything, has a real existence.
STRANGER: Then we must not attempt to attribute to not-being number either in the singular or plural?
THEAETETUS: The argument implies that we should be wrong in doing so.
STRANGER: But how can a man either express in words or even conceive in thought things which are not or a thing which is not without number?
THEAETETUS: How indeed?
STRANGER: When we speak of things which are not, are we not attributing plurality to not-being?
THEAETETUS: Certainly.
STRANGER: But, on the other hand, when we say 'what is not,' do we not attribute unity?
THEAETETUS: Manifestly.
STRANGER: Nevertheless, we maintain that you may not and ought not to attribute being to not-being?
THEAETETUS: Most true.
STRANGER: Do you see, then, that not-being in itself can neither be spoken, uttered, or thought, but that it is unthinkable, unutterable, unspeakable, indescribable?
THEAETETUS: Quite true.
STRANGER: But, if so, I was wrong in telling you just now that the difficulty which was coming is the greatest of all.
THEAETETUS: What! is there a greater still behind?
STRANGER: Well, I am surprised, after what has been said already, that you do not see the difficulty in which he who would refute the notion of not-being is involved. For he is compelled to contradict himself as soon as he makes the attempt.
THEAETETUS: What do you mean? Speak more clearly.
STRANGER: Do not expect clearness from me. For I, who maintain that not-being has no part either in the one or many, just now spoke and am still speaking of not-being as one; for I say 'not-being.' Do you understand?
THEAETETUS: Yes.
STRANGER: And a little while ago I said that not-being is unutterable, unspeakable, indescribable: do you follow?
THEAETETUS: I do after a fashion.
STRANGER: When I introduced the word 'is,' did I not contradict what I said before?
THEAETETUS: Clearly.
STRANGER: And in using the singular verb, did I not speak of not-being as one?
THEAETETUS: Yes.
STRANGER: And when I spoke of not-being as indescribable and unspeakable and unutterable, in using each of these words in the singular, did I not refer to not-being as one?
THEAETETUS: Certainly.
STRANGER: And yet we say that, strictly speaking, it should not be defined as one or many, and should not even be called 'it,' for the use of the word 'it' would imply a form of unity.
THEAETETUS: Quite true.
STRANGER: How, then, can any one put any faith in me? For now, as always, I am unequal to the refutation of not-being. And therefore, as I was saying, do not look to me for the right way of speaking about not-being; but come, let us try the experiment with you.
THEAETETUS: What do you mean?
STRANGER: Make a noble effort, as becomes youth, and endeavour with all your might to speak of not-being in a right manner, without introducing into it either existence or unity or plurality.
THEAETETUS: It would be a strange boldness in me which would attempt the task when I see you thus discomfited.
STRANGER: Say no more of ourselves; but until we find some one or other who can speak of not-being without number, we must acknowledge that the Sophist is a clever rogue who will not be got out of his hole.
THEAETETUS: Most true.