The Republic by Plato Part 1 Page 32

I say that if you want really to know what justice is, you should not only ask but answer, and you should not seek honour to yourself from the refutation of an opponent, but have your own answer; for there is many a one who can ask and cannot answer. And now I will not have you say that justice is duty or advantage or profit or gain or interest, for this sort of nonsense will not do for me; I must have clearness and accuracy.

I was panic-stricken at his words, and could not look at him without trembling. Indeed I believe that if I had not fixed my eye upon him, I should have been struck dumb: but when I saw his fury rising, I looked at him first, and was therefore able to reply to him.

Thrasymachus, I said, with a quiver, don’t be hard upon us. Polemarchus and I may have been guilty