In all affairs it's a healthy thing now and then to hang a question mark on the things you have long taken for granted.

Opinions which justify cruelty are inspired by cruel impulses.

Descartes, the father of modern philosophy ... would never-so he assures us-have been led to construct his philosophy if he had had only one teacher, for then he would have believed what he had been told; but, finding that his professors disagreed with each other, he was forced to conclude that no existing doctrine was certain.

Religions which have any very strong hold over men's actions have generally some instinctive basis.

Whoever wishes to become a philosopher must learn not to be frightened by absurdities.

Envy, in fact, is one form of a vice, partly moral, partly intellectual, which consists in seeing things never in themselves, but only in their relations.

Sir Arthur Eddington deduces religion from the fact that atoms do not obey the laws of mathematics. Sir James Jeans deduces it from the fact that they do.