Rhetoric is useful because the true and the just are naturally superior to their opposites, so that, if decisions are improperly made, they must owe their defeat to their own advocates; which is reprehensible. Further, in dealing with certain persons, even if we possessed the most accurate scientific knowledge, we should not find it easy to persuade them by the employment of such knowledge. For scientific discourse is concerned with instruction, but in the case of such persons instruction is impossible.

Life is full of chances and changes, and the most prosperous of men may in the evening of his days meet with great misfortunes.

All art is concerned with coming into being; for it is concerned neither with things that are, or come into being by necessity, nor with things that do so in accordance with nature.

Nor need it cause surprise that things disagreeable to the good man should seem pleasant to some men; for mankind is liable to many corruptions and diseases, and the things in question are not really pleasant, but only pleasant to these particular persons, who are in a condition to think them so.

The vigorous are no better than the lazy during one half of life, for all men are alike when asleep.

Again, it is possible to fail in many ways (for evil belongs to the class of the unlimited and good to that of the limited), while to succeed is possible only in one way (for which reason also one is easy and the other difficult—to miss the mark easy, to hit it difficult); for these reasons also, then, excess and defect are characteristic of vice, and the mean of virtue; For men are good in but one way, but bad in many.

Two characteristic marks have above all others been recognized as distinguishing that which has soul in it from that which has not - movement and sensation.