A man's acts are partly determined by spontaneous impulse, partly by the conscious and unconscious effects of the various groups to which he belongs.

Human nature being what it is, people will insist upon getting some pleasure out of life.

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.

The whole of theology, in regard to hell no less than to heaven, takes it for granted that Man is what is of most importance in the Universe of created beings. Since all theologians are men, this postulate has met with little opposition.

Remember your humanity, and forget the rest.

The man who is unhappy will, as a rule, adopt an unhappy creed, while the man who is happy will adopt a happy creed; each may attribute his happiness or unhappiness to his beliefs, while the real causation is the other way round.

There seems scarcely any limit to what could be done in the way of producing a good world, if only men would use science wisely.