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?