The root of the matter is a very simple and old fashioned thing... love or compassion. If you feel this, you have a motive for existence, a guide for action, a reason for courage, an imperative necessity for intellectual honesty.

A million million years gives us some time to prepare for the end . . . let us make the best of it.

I've always thought respectable people scoundrels, and I look anxiously at my face every morning for signs of my becoming a scoundrel.

Change is one thing, progress is another.

Children, after being limbs of Satan in traditional theology and mystically illuminated angels in the minds of educational reformers, have reverted to being little devils; not theological demons inspired by the evil one, but scientific Freudian abominations inspired by the unconscious.

At the age of eleven, I began Euclid, with my brother as my tutor. ... I had not imagined that there was anything so delicious in the world. After I had learned the fifth proposition, my brother told me that it was generally considered difficult, but I had found no difficulty whatsoever. This was the first time it had dawned on me that I might have some intelligence.

Mathematics takes us into the region of absolute necessity, to which not only the actual word, but every possible word, must conform.