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.

The character which results from wealth is that of a prosperous fool.

Man perfected by society is the best of all animals; he is the most terrible of all when he lives without law and without justice. If he finds himself an individual who cannot live in society, or who pretends he has need of only his own resources do not consider him as a member of humanity; he is a savage beast or a god.

A friend is a second self.

Think as the wise men think, but talk like the simple people do.

There also appears to be another element in the soul, which, though irrational, yet in a manner participates in rational principle.

The energy of the mind is the essence of life.