Evil is the vulgar lover who loves the body rather than the soul, inasmuch as he is not even stable, because he loves a thing which is in itself unstable, and therefore when the bloom of youth which he was desiring is over, he takes wing and flies away, in spite of all his words and promises; whereas the love of the noble disposition is life-long, for it becomes one with the everlasting.
PlatoSOCRATES: Perhaps we may be wrong; if so, you in your wisdom should convince us that we are mistaken in preferring justice to injustice. THRASYMACHUS: And how am I to convince you, he said, if you are not already convinced by what I have just said; what more can I do for you? Would you have me put the proof bodily into your souls?
Plato