The man who is all morality and intellect, although he may be good and even great, is, after all, only half a man.

There is the greatest practical benefit in making a few failures early in life.

The vast results obtained by Science are won by no mystical faculties, by no mental processes other than those which are practicedby every one of us, in the humblest and meanest affairs of life. A detective policeman discovers a burglar from the marks made by his shoe, by a mental process identical with that by which Cuvier restored the extinct animals of Montmartre from fragments of their bones.

Nothing great in science has ever been done by men, whatever their powers, in whom the divine afflatus of the truth-seeker was wanting.

The birth of science was the death of superstition.

There are savages without God in any proper sense of the word, but none without ghosts.

Agnosticism simply means that a man shall not say that he knows or believes that for which he has no grounds for professing to believe.