Socrates: We agree—do we not?—that there is such a thing as false, and also such a thing as true opinion?
Protarchus: Yes.
Socrates: And pleasure and pain, as I was just now saying, are often consequent upon these—upon true and false opinion, I mean.
Protarchus: Very true.
Socrates: And do not opinion and the endeavour to form an opinion always spring from memory and perception?
Protarchus: Certainly.
Socrates: Might we imagine the process to be something of this nature?
Protarchus: Of what nature?
Socrates: An object may be often seen at a distance not very clearly, and the seer may want to determine what it is which he sees.
Protarchus: Very likely.
Socrates: Soon he begins to interrogate himself.
Protarchus: In what manner?
Socrates: He asks himself—“What is that which appears to be standing by the rock under the tree?” This is the question which he may be supposed to put to himself when he sees such an appearance.
Protarchus: True.
Socrates: To which he may guess the right answer, saying as if in a whisper to himself—“It is a man.”
Protarchus: Very good.
Socrates: Or again, he may be misled, and then he will say—“No, it is a figure made by the shepherds.”
Protarchus: Yes.
Socrates: And if he has a companion, he repeats his thought to him in articulate sounds, and what was before an opinion, has now become a proposition.
Protarchus: Certainly.
Socrates: But if he be walking alone when these thoughts occur to him, he may not unfrequently keep them in his mind for a considerable time.
Protarchus: Very true.
Socrates: Well, now, I wonder whether you would agree in my explanation of this phenomenon.
Protarchus: What is your explanation?
Socrates: I think that the soul at such times is like a book.