Clergymen almost necessarily fail in two ways as teachers of morals. They condemn acts which do no harm and they condone acts which do great harm.

I used, when I was younger, to take my holidays walking. I would cover 25 miles a day, and when the evening came I had no need of anything to keep me from boredom, since the delight of sitting amply sufficed.

Uncertainty in the pressure of vivid hopes and fears is painful, but must be endured if we wish to live without the support of comforting fairy tales.

The resistance to a new idea increases by the square of its importance.

I feel life is so small unless it has windows into other worlds.

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.

I say people who feel they must have a faith or religion in order to face life are showing a kind of cowardice, which in any other sphere would be considered contemptible. But when it is in the religious sphere it is thought admirable, and I cannot admire cowardice whatever sphere it is in.