Whether science-and indeed civilization in general-can long survive depends upon psychology, that is to say, it depends upon what human beings desire.

All definite knowledge - so I should contend - belongs to science; all dogma as to what surpasses definite knowledge belongs to theology. But between theology and science there is a No Man's Land, exposed to attack by both sides; this No Man's Land is philosophy.

Only in thought is man a God; in action and desire we are the slaves of circumstance.

Work is of two kinds: first, altering the position of matter at or near the earth's surface relative to other matter; second, telling other people to do so.

More and more people are becoming unable to accept traditional [religious] beliefs. If they think that, apart from these beliefs, there is no reason for kindly behaviour, the results may be needlessly unfortunate. That is why it is important to show that no supernatural reasons are needed to make [people] kind and to prove that only through kindness can the human race achieve happiness.

Do not feel envious of the happiness of those who live in a fool's paradise, for only a fool will think that is happiness.

Almost all education has a political motive.