The Republic by Plato Part 3 Page 78

All that, Socrates, is excellent; but I should like to put a question to you: Ought there not to be good physicians in a State, and are not the best those who have treated the greatest number of constitutions good and bad?

and are not the best judges in like manner those who are acquainted with all sorts of moral natures?

Yes, I said, I too would have good judges and good physicians. But do you know whom I think good?

Will you tell me?

I will, if I can. Let me however note that in the same question you join two things which are not the same.

How so? he asked.

Why, I said, you join physicians and judges. Now the most skilful physicians are those who,