Plato, The Republic

"But I don't think we shall quarrel about a word - the subject of our inquiry is too important for that."

"So when a man surrenders to the sound of music and lets its sweet, soft, mournful strains, which we have just described, be funnelled into his soul through his ears, and gives up all his time to the glamorous moanings of song, the effect at first on his energy and initiative of mind, if he has any, is to soften it as iron is softened in a furnace, and made workable instead of hard and unworkable: but if he persists and does not break the enchantment, the next stage is that it melts and runs, till the spirit has quite run out of him and his mental sinews (if I may so put it) are cut, and he has become what Homer calls "a feeble fighter"."

"Physical excellence does not of itself produce a good mind and character: on the other hand, excellence of mind and character will make the best of the physique it is given."

"Money-makers are tiresome company, as they have no standard but cash value."

"...harmony that would fittingly imitate the utterances and accents of a brave man who is engaged in warfare or in any enforced business, and who, when he has failed […] confronts fortune with steadfast endurance and repels her strokes"

"Musical innovation is full of danger to the State, for when modes of music change, the fundamental laws of the State always change with them."

"... when someone sees a soul disturbed and unable to see something, he won't laugh mindlessly, but he'll take into consideration whether it has come from a brighter life and is dimmed through not having yet become accustomed to the dark or whether it has come from greater ignorance into greater light and is dazzled by the increased brillance."

"Have you ever sensed that our soul is immortal and never dies?"

"If women are expected to do the same work as men, we must teach them the same things."

"The heaviest penalty for declining to rule is to be ruled by someone inferior to yourself."

"You take the words in the sense which is most damaging to the argument."

"That's what education should be," I said, "the art of orientation. Educators should devise the simplest and most effective methods of turning minds around. It shouldn't be the art of implanting sight in the organ, but should proceed on the understanding that the organ already has the capacity, but is improperly aligned and isn't facing the right way."

"Opinion is the medium between knowledge and ignorance"

"And whenever any one informs us that he has found a man who knows all the arts, and all things else that anybody knows, and every single thing with a higher degree of accuracy than any other man –whoever tells us this, I think that we can only imagine him to be a simple creature who is likely to have been deceived by some wizard or actor whom he met, and whom he thought all-knowing, because he himself was unable to analyze the nature of knowledge and ignorance and imitation."

"Those who don't know must learn from those who do."

"Either we shall find what it is we are seeking or at least we shall free ourselves from the persuasion that we know what we do not know."

"Bodily exercise, when compulsory, does no harm to the body; but knowledge which is acquired under compulsion obtains no hold on the mind."

"Musical training is a more potent instrument than any other, because rhythm and harmony find their way into the inward places of the soul."

"The philosopher whose dealings are with divine order himself acquires the characteristics of order and divinity."