The Republic by Plato Part 1 Page 48

In the strictest of all senses, he said. And now cheat and play the informer if you can; I ask no quarter at your hands. But you never will be able, never.

And do you imagine, I said, that I am such a madman as to try and cheat, Thrasymachus? I might as well shave a lion.

Why, he said, you made the attempt a minute ago, and you failed.

Enough, I said, of these civilities. It will be better that I should ask you a question: Is the physician, taken in that strict sense of which you are speaking, a healer of the sick or a maker of money? And remember that I am now speaking of the true physician.

A healer of the sick, he replied.

And the pilot — that is to say, the true pilot —