Those were not his words, rejoined Polemarchus.

SOCRATES - THRASYMACHUS

Never mind, I replied, if he now says that they are, let us
accept his statement. Tell me, Thrasymachus, I said, did you
mean by justice what the stronger thought to be his interest,
whether really so or not?

Certainly not, he said. Do you suppose that I call him who is
mistaken the stronger at the time when he is mistaken?

Yes, I said, my impression was that you did so, when you admitted
that the ruler was not infallible but might be sometimes mistaken.

You argue like an informer, Socrates. Do you mean, for example,
that he who is mistaken about the sick is a physician in that he is
mistaken? or that he who errs in arithmetic or grammar is an arithmetician
or grammarian at the me when he is making the mistake, in respect
of the mistake? True, we say that the physician or arithmetician
or grammarian has made a mistake, but this is only a way of speaking;
for the fact is that neither the grammarian nor any other person
of skill ever makes a mistake in so far as he is what his name implies;
they none of them err unless their skill fails them, and then
they cease to be skilled artists. No artist or sage or ruler
errs at the time when he is what his name implies; though he is
commonly said to err, and I adopted the common mode of speaking.
But to be perfectly accurate, since you are such a lover of accuracy,
we should say that the ruler, in so far as he is the ruler,