The demand for certainty is one which is natural to man, but is nevertheless an intellectual vice. If you take your children for a picnic on a doubtful day, they will demand a dogmatic answer as to whether it will be fine or wet, and be disappointed in you when you cannot be sure.

Respectability, regularity, and routine - the whole cast-iron discipline of a modern industrial society - have atrophied the artistic impulse, and imprisoned love so that it can no longer be generous and free and creative, but must be either stuffy or furtive.

The only thing that will redeem mankind is cooperation.

Force plays a much larger part in the government of the world than it did before 1914, and what is especially alarming, force tends increasingly to fall into the hands of those who are enemies of civilization.

I think we ought always to entertain our opinions with some measure of doubt. I shouldn't wish people dogmatically to believe any philosophy, not even mine.

My whole religion is this: do every duty, and expect no reward for it, either here or hereafter.

It is not my prayer and humility that you cause things to go as you wish, but by acquiring a knowledge of natural laws.