THEAETETUS: Unquestionably.
STRANGER: And it would be no sentence at all if there were no subject, for, as we proved, a sentence which has no subject is impossible.
THEAETETUS: Quite true.
STRANGER: When other, then, is asserted of you as the same, and not-being as being, such a combination of nouns and verbs is really and truly false discourse.
THEAETETUS: Most true.
STRANGER: And therefore thought, opinion, and imagination are now proved to exist in our minds both as true and false.
THEAETETUS: How so?
STRANGER: You will know better if you first gain a knowledge of what they are, and in what they severally differ from one another.
THEAETETUS: Give me the knowledge which you would wish me to gain.
STRANGER: Are not thought and speech the same, with this exception, that what is called thought is the unuttered conversation of the soul with herself?