In the part of this universe that we know there is great injustice, and often the good suffer, and often the wicked prosper, and one hardly knows which of those is the more annoying.

One of the symptoms of approaching nervous breakdown is the belief that one's work is terribly important, and that to take a holiday would bring all kinds of disaster. If I were a medical man, I should prescribe a holiday to any patient who considered his or her work important.

The wise use of leisure, it must be conceded, is a product of civilization and education.

Emphatic and reiterated assertion, especially during childhood, produces in most people a belief so firm as to have a hold even over the unconscious.

We are ... led to a somewhat vague distinction between what we may call "hard" data and "soft" data. This distinction is a matter of degree, and must not be pressed; but if not taken too seriously it may help to make the situation clear. I mean by "hard" data those which resist the solvent influence of critical reflection, and by "soft" data those which, under the operation of this process, become to our minds more or less doubtful.

At the age of eleven, I began Euclid, with my brother as my tutor. This was one of the great events of my life, as dazzling as first love. I had not imagined there was anything so delicious in the world. From that moment until I was thirty-eight, mathematics was my chief interest and my chief source of happiness.

Science seems to be at war with itself.... Naive realism leads to physics, and physics, if true, shows naive realism to be false. Therefore naive realism, if true, is false; therefore it is false.