It is essential to happiness that our way of living should spring from our own deep impulses and not from the accidental tastes and desires of those who happen to be our neighbors, or even our relations.

The commonest objection to birth control is that it is against nature.

... the word "theory" ... was originally an Orphic word, which Cornford interprets as "passionate sympathetic contemplation" ... For Pythagoras, the "passionate sympathetic contemplation" was intellectual, and issued in mathematical knowledge ... To those who have reluctantly learnt a little mathematics in school this may seem strange; but to those who have experienced the intoxicating delight of sudden understanding that mathematics gives, from time to time, to those who love it, the Pythagorean view will seem completely natural.

To be out of harmony with one's surroundings is of course a misfortune, but it is not always a misfortune to be avoided at all costs. Where the environment is stupid or prejudiced or cruel, it is a sign of merit to be out of harmony with it.

One of the chief triumphs of modern mathematics consists in having discovered what mathematics really is.

As men begin to grow civilized, they cease to be satisfied with mere taboos.

Philosophy seems to me on the whole a rather hopeless business.