Plato, The Republic

"I am the wisest man alive, for I know one thing, and that is that I know nothing."

"It is only just that anything that grows up on its own should feel it has nothing to repay for an upbringing which it owes no one."

"Justice is useful when money is useless."

"Imagine that the keeper of a huge, strong beast notices what makes it angry, what it desires, how it has to be approached and handled, the circumstances and the conditions under which it becomes particularly fierce or calm, what provokes its typical cries, and what tones of voice make it gentle or wild. Once he's spent enough time in the creature's company to acquire all this information, he calls it knowledge, forms it into a systematic branch of expertise, and starts to teach it, despite total ignorance, in fact, about which of the creature's attitudes and desires is commendable or deplorable, good or bad, moral or immoral. His usage of all these terms simply conforms to the great beast's attitudes, and he describes things as good or bad according to its likes and dislikes, and can't justify his usage of the terms any further, but describes as right and good the things which are merely indispensable, since he hasn't realised and can't explain to anyone else how vast a gulf there is between necessity and goodness."

"I shall try to persuade first the Rulers and soldiers, and then the rest of the community, that the upbringing and education we have given them was all something that happened to them only in a dream. In reality they were fashioned and reared, and their arms and equipment manufactured, in the depths of the earth, and Earth herself, their mother, brought them up, when they were complete, into the light of day; so now they must think of the land in which they live as their mother and protect her if she is attacked, while their fellow citizens they must regard as brothers born of the same mother earth…. That is the story. Do you know of any way of making them believe it?” “Not in the first generation,” he said, “but you might succeed with the second, and later generations."

"Here's something else I'd like your opinion about," I said. "If he went back underground and sat down again in the same spot, wouldn't the sudden transition from the sunlight mean that his eyes would be overwhelmed by darkness" "Certainly," he replied. "Now, the process of adjustment would be quite long this time, and suppose that before his eyes had settled down and while he wasn't seeing well, he had once again to compete against those same old prisoners at identifying those shadows. Would he make a fool of himself? Wouldn't they say that he'd come back from his upward journey with his eyes ruined, and that it wasn't even worth trying to go up there? And would they -- if they could -- grab hold of anyone who tried to set them free and take them up there and kill him?"

"The tools that would teach men their own use would be beyond price."

"Excess of liberty, whether it lies in state or individuals, seems only to pass into excess of slavery."

"The author's Socrates admonishes paramount awareness human limitations. If we do good to those we evaluate as good and evil to those we evaluate at the evil, and we are wrong, we have been made the world less just."

"We've heard many people say and have often said ourselves that justice is doing one's own work and not meddling with what isn't one's own ... Then, it turns out that this doing one's own work-provided that it comes to be in a certain way-is justice."

"[W]hen men have both done and suffered injustice and have had experience of both, not being able to avoid the one and obtain the other, they think that they had better agree among themselves to have neither; hence there arise laws and mutual covenants; and that which is ordained by law is termed by them lawful and just. This they affirm to be the origin and nature of justice;—it is a mean or compromise, between the best of all, which is to do injustice and not be punished, and the worst of all, which is to suffer injustice without the power of retaliation; and justice, being at a middle point between the two, is tolerated not as a good, but as the lesser evil…"

"...in the running of cities, virtually nothing is done by anyone that is conducive to political health, nor is there a single ally with whom one might go to the aid of justice and still remain alive; it would be a case of a solitary human among wild animals, neither wanting to join in their depredations nor able to stand alone against their collective savagery, dead before he'd done any good to his city or friends and useless both to himself and everybody else. Once a person has made all these calculations, he keeps his peace and minds his own business, like someone withdrawing from the prevailing wind into the shelter of a wall in a storm of dust or rain, and as he sees everyone else filling themselves full of lawlessness he is content if he himself can somehow live out life here untainted by injustice and impious actions, and leave it with fine hopes and in a spirit of kindness and good will."

"Old age has a great sense of calm and freedom when the passions relax their hold, then, as Sophocles says, we are free from the grasp, not of one mad master only, but of many."

"He who is of a calm and happy nature will hardly feel the pressure of age. But to him who is of an opposite disposition, youth and age are equally a burden."

"Then as for those who gaze upon many beautiful things but don't see the beautiful itself, and aren't even capable of following someone else who leads them to it, and upon many just things but not the just itself, and all the things like that, we'll claim that they accept the seeming of everything but discern nothing of what they have opinions about."

"The worst type of man behaves as badly in his waking life as some men do in their dreams."

"What is honored in a culture gets cultivated there."

"Haven't you noticed that opinion without knowledge is always a poor thing? At the best it is blind—isn't anyone who holds a true opinion without understanding like a blind man on the right road?"

"[W]hen men have both done and suffered injustice and have had experience of both, not being able to avoid the one and obtain the other, they think that they had better agree among themselves to have neither; hence there arise laws and mutual covenants; and that which is ordained by law is termed by them lawful and just. This they affirm to be the origin and nature of justice;—it is a mean or compromise,between the best of all, which is to do injustice and not be punished, and the worst of all, which is to suffer injustice without the power of retaliation; and justice, being at a middle point between the two, is tolerated not as a good, but as the lesser evil…"

"There is nothing which for my part I like better, Cephalus, than conversing with aged men; for I regard them as travellers who have gone a journey which I too may have to go, and of whom I ought to inquire, whether the way is smooth and easy, or rugged and difficult."