All men by nature desire to know. An indication of this is the delight we take in our senses; for even apart from their usefulness they are loved for themselves...

By 'life,' we mean a thing that can nourish itself and grow and decay.

A tragedy is the imitation of an action that is serious and also, as having magnitude, complete in itself . . . with incidents arousing pity and fear, wherewith to accomplish its catharsis of such emotions.

Happiness is a thing honored and perfect. This seems to be borne out by the fact that it is a first principle or starting-point, since all other things that all men do are done for its sake; and that which is the first principle and cause of things good we agree to be something honorable and divine.

A friend is simply one soul in two bodies.

The virtue of justice consists in moderation, as regulated by wisdom.

Even when laws have been written down, they ought not always to remain unaltered. As in other sciences, so in politics, it is impossible that all things should be precisely set down in writing; for enactments must be universal, but actions are concerned with particulars. Hence we infer that sometimes and in certain cases laws may be changed.