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 time when he is making the mistake, in respect of the mistake? True, we say