n shadow,
do not quarrel with me on that account, as the manner of women is when
their first children are taken from them. For I have actually known some
who were ready to bite me when I deprived them of a darling folly; they
did not perceive that I acted from goodwill, not knowing that no god is
the enemy of man--that was not within the range of their ideas; neither
am I their enemy in all this, but it would be wrong for me to admit
falsehood, or to stifle the truth. Once more, then, Theaetetus, I repeat
my old question, 'What is knowledge?'--and do not say that you cannot
tell; but quit yourself like a man, and by the help of God you will be
able to tell.

THEAETETUS: At any rate, Socrates, after such an exhortation I should be
ashamed of not trying to do my best. Now he who knows perceives what he
knows, and, as far as I can see at present, knowledge is perception.

SOCRATES: Bravely said, boy; that is the way in which you should express
your opinion. And now, let us examine together this conception of yours,
and see whether it is a true birth or a mere wind-egg:--You say that
knowledge is perception?

THEAETETUS: Yes.

SOCRATES: Well, you have delivered yourself of a very important doctrine
about knowledge; it is indeed the opinion of Protagoras, who has another
way of expressing it. Man, he says, is the measure of all things, of the
existence of things that are, and of the non-existence of things that
are not:--You have read him?

THEAETETUS: O yes, again and again.

SOCRATES: Does he not say that things are to you such as they appear to
you, and to me such as they appear to me, and that you and I are men?

THEAETETUS: Yes, he says so.

SOCRATES: A wise man is not likely to talk nonsense. Let us try to
understand him: the same wind is blowing, and yet one of us may be cold
and the other not, or one may be slightly and the other very cold?

THEAETETUS: Quite true.

SOCRATES: Now is the wind, regarded not in relation to us but
absolutely, cold or not; or are we to say, with Protagoras, that the
wind is cold to him who is cold, and not to him who is not?

THEAETETUS: I suppose the last.

SOCRATES: Then it must appear so to each of them?

THEAETETUS: Yes.

SOCRATES: And 'appears to him' means the same as 'he perceives.'

THEAETETUS: True.

SOCRATES: Then appearing and perceiving coincide in the case of hot and
cold, and in similar instances; for things appear, or may be supposed to
be, to each one