True happiness comes from gaining insight and growing into your best possible self. Otherwise all you're having is immediate gratification pleasure, which is fleeting and doesn't grow you as a person.
Every art and every inquiry, and similarly every action and pursuit, is thought to aim at some good; and for this reason the good has rightly been declared to be that at which all things aim.
Tragedy is an imitation not only of a complete action, but of events inspiring fear and pity. Such an effect is best produced when the events come on us by surprise; and the effect is heightened when, at the same time, they follow as cause and effect. The tragic wonder will then be great than if they happened of themselves or by accident; for even coincidences are most striking when they have an air of design.
Since the whole city has one end, it is manifest that education should be one and the same for all, and that it should be public, and not private - not as at present, when every one looks after his own children separately, and gives them separate instruction of the sort which he thinks best; the training in things which are of common interest should be the same for all. Neither must we suppose that any one of the citizens belongs to himself, for they all belong to the state, and are each of them a part of the state, and the care of each part is inseparable from the care of the whole.
... the good for man is an activity of the soul in accordance with virtue, or if there are more kinds of virtue than one, in accordance with the best and most perfect kind.
Wretched, ephemeral race, children of chance and tribulation, why do you force me to tell you the very thing which it would be most profitable for you not to hear? The very best thing is utterly beyond your reach: not to have been born, not to be, to be nothing. However, the second best thing for you is: to die soon.