Come then, Thrasymachus, said I, let us start anew, and oblige us by answering: Do you assert that a perfect injustice is more profitable than an equally perfect justice?
Most decidedly I do; and I have said why.
Pray how do you describe them under another aspect? Probably you call one of them a virtue, and the other a vice?
Undoubtedly.
That is, justice a virtue, and injustice a vice?
A likely thing, my facetious friend, when I assert that injustice is profitable, and justice the reverse.
Then what do you say?
Just the contrary.
Do you call justice a vice?
No; but I call it very egregious good nature.
Then do you call injustice ill nature?
No: I call it good policy. 

-- Plato