Misanthropy ariseth from a man trusting another without having sufficient knowledge of his character, and, thinking him to be truthful, sincere, and honourable, finds a little afterwards that he is wicked, faithless, and then he meets with another of the same character. When a man experiences this often, and more particularly from those whom he considered his most dear and best friends, at last, having frequently made a slip, he hates the whole world, and thinks that there is nothing sound at all in any of them.
PlatoFor not by art does the poet sing, but by power divine. Had he learned by rules of art, he would have known how to speak not of one theme only, but of all; and therefore God takes away the minds of poets, and uses them as his ministers, as he also uses diviners and holy prophets, in order that we who hear them may know them to be speaking not of themselves who utter these priceless words in a state of unconsciousness, but that God himself is the speaker, and that through them he is conversing with us.
PlatoYou may be sure, dear Crito, that inaccurate language is not only in itself a mistake: it implants evil in men's souls.
PlatoThe well-nurtured youth is one who would see most clearly whatever was amiss in ill-made works of man or ill-grown works of nature, and with a just distaste would blame and hate the ugly even from his earliest years and would give delighted praise to beauty, receiving it into his soul and being nourished by it, so that he became a man of gentle heart.
Plato