What Galileo and Newton were to the seventeenth century, Darwin was to the nineteenth.

The late F. W. H. Myers used to tell how he asked a man at a dinner table what he thought would happen to him when he died. The man tried to ignore the question, but, on being pressed, replied: "Oh well, I suppose I shall inherit eternal bliss, but I wish you wouldn't talk about such unpleasant subjects."

Affection cannot be created; it can only be liberated.

Very few men can be genuinely happy in a life involving continual self-assertion against the skepticism of the mass of mankind, unless they can shut themselves up in a coterie and forget the cold outer world. The man of science has no need of a coterie, since he is thought well of by everybody except his colleagues. The artist, on the contrary, is in the painful situation of having to choose between being despised and being despicable.

If one lived for ever the joys of life would inevitably in the end lose their savour. As it is, they remain perennially fresh.

... 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.

Adventurous men enjoy shipwrecks, mutinies, earthquakes, conflagrations, and all kinds of unpleasant experiences. They say to themselves, for example, 'So this is what an earthquake is like,' and it gives them pleasure to have their knowledge of the world increased by this new item.