The Republic by Plato Part 1 Page 74

I may be in earnest or not, but what is that to you? — to refute the argument is your business.

Very true, I said; that is what I have to do: But will you be so good as answer yet one more question? Does the just man try to gain any advantage over the just?

Far otherwise; if he did he would not be the simple amusing creature which he is.

And would he try to go beyond just action?

He would not.

And how would he regard the attempt to gain an advantage over the unjust; would that be considered by him as just or unjust?

He would think it just, and would try to gain the advantage; but he would not be able.