THEAETETUS: Who, Socrates, would dare to say so?
SOCRATES: But we must say so, if the previous argument is to be maintained.
THEAETETUS: What do you mean? I am not quite sure that I understand you, though I have a strong suspicion that you are right.
SOCRATES: As thus: he who sees knows, as we say, that which he sees; for perception and sight and knowledge are admitted to be the same.
THEAETETUS: Certainly.
SOCRATES: But he who saw, and has knowledge of that which he saw, remembers, when he closes his eyes, that which he no longer sees.
THEAETETUS: True.
SOCRATES: And seeing is knowing, and therefore not-seeing is not-knowing?
THEAETETUS: Very true.
SOCRATES: Then the inference is, that a man may have attained the knowledge of something, which he may remember and yet not know, because he does not see; and this has been affirmed by us to be a monstrous supposition.