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That is implied in the argument.

Then after all, the just man has turned out to be a thief.
And this is a lesson which I suspect you must have learnt out
of Homer; for he, speaking of Autolycus, the maternal grand-
father of Odysseus, who is a favorite of his, affirms that

"He was excellent above all men in theft and perjury."

And so, you and Homer and Simonides are agreed that justice
is an art of theft; to be practised, however, "for the good of
friends and for the harm of enemies"--that was what you were
saying?

No, certainly not that, though I do not now know what I
did say; but I still stand by the latter words.

Well, there is another question: By friends and enemies do
we mean those who are so really, or only in seeming?

Surely, he said, a man may be expected to love those whom
he thinks good, and to hate those whom he thinks evil.

Yes, but do not persons often err about good and evil: many
who are not good seem to be so, and conversely?

That is true.

Then to them the good will be enemies and the evil will be
their friends?
True.

And in that case they will be right in doing good to the evil
and evil to the good?

Clearly.

But the good are just and would not do an injustice?

True.

Then according to your argument it is just to injure those
who do no wrong?

Nay, Socrates; the doctrine is immoral.

Then I suppose that we ought to do good to the just and
harm to the unjust?

I like that better.

But see the consequence: Many a man who is ignorant of
human nature has friends who are bad friends, and in that case
he ought to do harm to them; and he has good enemies whom
he ought to benefit; but, if so, we shall be saying the very op-
posite of that which we affirmed to be the meaning of Simon-
ides.

Very true, he said; and I think that we had better correct
an error into which we seem to have fallen in the use of the
words "friend" and "enemy."

What was the error, Polemarchus? I asked.