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.