All science has one aim, namely, to find a theory of nature.

Whatever you do, you need courage. Whatever course you decide upon, there is always someone to tell you that you are wrong.

All successful men have agreed in one thing -- they were causationists. They believed that things went not by luck, but by law; that there was not a weak or a cracked link in the chain that joins the first and last of things.

Pride can go without domestics, without fine clothes, can live in a house with two rooms, can eat potato, purslain, beans, lyed corn, can work on the soil, can travel afoot, can talk with poor men, or sit silent well contented with fine saloons. But vanity costs money, labor, horses, men, women, health and peace, and is still nothing at last; a long way leading nowhere.--Only one drawback; proud people are intolerably selfish, and the vain are gentle and giving.

Let none presume to measure the irregularities of Michael Angelo or Socrates by village scales.

Nothing can bring you peace but yourself. Nothing can bring you peace but the triumph of principles.

It is the fault of our rhetoric that we cannot strongly state one fact without seeming to belie some other.