I should like to believe my people's religion, which was just what I could wish, but alas, it is impossible. I have really no religion, for my God, being a spirit shown merely by reason to exist, his properties utterly unknown, is no help to my life. I have nor the parson's comfortable doctrine that every good action has its reward, and every sin is forgiven. My whole religion is this: do every duty, and expect no reward for it, either here or hereafter.

War grows out of ordinary human nature.

The Axiom of Choice is necessary to select a set from an infinite number of socks, but not an infinite number of shoes.

Philosophy is to be studied, not for the sake of any definite answers to its questions, since no definite answers can, as a rule, be known to be true, but rather for the sake of the questions themselves; because these questions enlarge our conception of what is possible, enrich our intellectual imagination and diminish the dogmatic assurance which closes the mind against speculation; but above all because, through the greatness of the universe which philosophy contemplates, the mind is also rendered great, and becomes capable of that union with the universe which constitutes its highest good.

The best life is the one in which the creative impulses play the largest part and the possessive impulses the smallest.

To be happy in this world, especially when youth is past, it is necessary to feel oneself not merely an isolated individual whose day will soon be over, but part of the stream of life flowing on from the first germ to the remote and unknown future.

To create a healthy philosophy you should renounce metaphysics but be a good mathematician.