We now possess four principles of morality: 1) a philosophical: do good for its own sake, out of respect for the law; 2) a religious: do good because it is God's will, out of love of God; 3) a human: do good because it will promote your happiness, out of self-love; 4) a political: do good because it will promote the welfare of the society of which you are a part, out of love of society having regard to yourself. But is this not all one single principle, only viewed from different sides?

A clever child brought up with a foolish one can itself become foolish. Man is so perfectible and corruptible he can become a fool through good sense.

With prophecies the commentator is often a more important man than the prophet.

There can hardly be a stranger commodity in the world than books. Printed by people who don't understand them; sold by people who don't understand them; bound, criticized and read by people who don't understand them; and now even written by people who don't understand them.

Why does a suppurating lung give so little warning and a sore on the finger so much?

Everyone is a genius at least once a year. The real geniuses simply have their bright ideas closer together.

The greatest events occur without intention playing any part in them; chance makes good mistakes and undoes the most carefully planned undertaking. The world's greatest events are not produced, they happen.