In science the successors stand upon the shoulders of their predecessors; where one man of supreme genius has invented a method, a thousand lesser men can apply it. ... In art nothing worth doing can be done without genius; in science even a very moderate capacity can contribute to a supreme achievement.

For the learning of every virtue there is an appropriate discipline, and for the learning of suspended judgment the best discipline is philosophy.

For over two thousand years it has been the custom among earnest moralists to decry happiness as something degraded and unworthy

Science is what you know, philosophy is what you don't know.

From the height of their disillusionment they look down upon those whom they despise as simple souls. For my part I have no sympathy with this outlook. All disenchantment is to me a malady, which, it is true, certain circumstances may render inevitable, but which none the less, when it occurs, is to be cured as soon as possible, not to be regarded as a higher form of wisdom.

A good world needs knowledge, kindliness, and courage; it does not need a regretful hankering after the past or a fettering of the free intelligence by the words uttered long ago by ignorant men.

Only mathematics and mathematical logic can say as little as the physicist means to say.