sophist   

Theaet. Exactly.
Str. Then he who says "not something" must say absolutely nothing.
Theaet. Most assuredly.
Str. And as we cannot admit that a man speaks and says nothing, he
who says "not-being" does not speak at all.
Theaet. The difficulty of the argument can no further go.
Str. 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.
Theaet. What do you mean? Do not be afraid to speak.
Str. To that which is, may be attributed some other thing which is?
Theaet. Certainly.
Str. But can anything which is, be attributed to that which is not?
Theaet. Impossible.
Str. And all number is to be reckoned among things which are?
Theaet. Yes, surely number, if anything, has a real existence.
Str. Then we must not attempt to attribute to not-being number
either in the singular or plural?
Theaet. The argument implies that we should be wrong in doing so.
Str. 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?
Theaet. How indeed?
Str. When we speak of things which are not attributing plurality
to not-being?
Theaet. Certainly.
Str. But, on the other hand, when we say "what is not," do we not
attribute unity?
Theaet. Manifestly.
Str. Nevertheless, we maintain that you may not and ought not to
attribute being to not-being?
Theaet. Most true.
Str. Do you see, then, that not-being in itself can neither be
spoken, uttered, or thought, but that it is unthinkable,
unutterable, unspeakable, indescribable?
Theaet. Quite true.
Str. But, if so, I was wrong in telling you just now that the
difficulty which was coming is the greatest of all.
Theaet. What! is there a greater still behind?
Str. 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.
Theaet. What do you mean? Speak more clearly.
Str. 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?
Theaet. Yes.
Str. And a little while ago I said that not-being is unutterable,
unspeakable, indescribable: do you follow?
Theaet. I do after a fashion.
Str. When I introduced the word "is," did I not contradict what I
said before?
Theaet. Clearly.
Str. And in using the singular verb, did I not speak of
not-being as
one?
Theaet. Yes.
Str. 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?
Theaet. Certainly.