A life which goes excessively against natural impulse is... likely to involve effects of strain that may be quite as bad as indulgence in forbidden impulses would have been. People who live a life which is unnatural beyond a point are likely to be filled with envy, malice and uncharitableness.

Reason may be a small force, but it is constant, and works always in one direction, while the forces of unreason destroy one another in futile strife.

I believe four ingredients are necessary for happiness: health, warm personal relations, sufficient means to keep you from want, and successful work.

One of the chief triumphs of modern mathematics consists in having discovered what mathematics really is.

Physics, owing to the simplicity of its subject matter, has reached a higher state of development than any other science.

Every great idea starts out as a blasphemy.

A good social system is not to be secured by making people unselfish, but, by making their own vital impulses fit in with other peoples. This is feasible. Those who have produced stoic philosophies have all had enough to eat and drink. I feel I shall find the truth on my deathbed and be surrounded by people too stupid to understand—fussing about medicines instead of searching for wisdom. I hate being all tidy like a book in a library where nobody reads – prison is horribly like that.