SOCRATES: Let me put the matter thus: When will there be more chance of deception—when the difference is large or small?
PHAEDRUS: When the difference is small.
SOCRATES: And you will be less likely to be discovered in passing by degrees into the other extreme than when you go all at once?
PHAEDRUS: Of course.
SOCRATES: He, then, who would deceive others, and not be deceived, must exactly know the real likenesses and differences of things?
PHAEDRUS: He must.
SOCRATES: And if he is ignorant of the true nature of any subject, how can he detect the greater or less degree of likeness in other things to that of which by the hypothesis he is ignorant?
PHAEDRUS: He cannot.
SOCRATES: And when men are deceived and their notions are at variance with realities, it is clear that the error slips in through resemblances?
PHAEDRUS: Yes, that is the way.