[263e]
and the several differences between them.
Theaetetus
Give me an opportunity.
Stranger
Well, then, thought and speech are the same; only the former, which is a silent inner conversation of the soul with itself, has been given the special name of thought. Is not that true?
Theaetetus
Certainly.
Stranger
But the stream that flows from the soul in vocal utterance through the mouth has the name of speech?
Theaetetus
True.
Stranger
And in speech we know there is just—
Theaetetus
What?
Stranger
Affirmation and negation
Theaetetus
Yes, we know that.