The most considerable difference I note among men is not in their readiness to fall into error, but in their readiness to acknowledge these inevitable lapses.
Economy does not lie in sparing money, but in spending it wisely.
The only question which any wise man can ask himself, and which any honest man will ask himself, is whether a doctrine is true or false.
The struggle for existence holds as much in the intellectual as in the physical world. A theory is a species of thinking, and its right to exist is coextensive with its power of resisting extinction by its rivals.
It is not who is right, but what is right, that is of importance.
I protest that if some great Power would agree to make me always think what is true and do what is right, on condition of being turned into a sort of clock and would up every morning before I got out of bed, I should instantly close with the offer.
The great thing in the world is not so much to seek happiness as to earn peace and self-respect.
Science is simply common sense at its best, that is, rigidly accurate in observation, and merciless to fallacy in logic.
History warns us that it is the customary fate of new truths to begin as heresies and to end as superstitions.
Patience and tenacity are worth more than twice their weight of cleverness.
The doctrine that all men are, in any sense, or have been, at any time, free and equal, is an utterly baseless fiction.
Science has fulfilled her function when she has ascertained and enunciated truth.
Science is organized common sense where many a beautiful theory was killed by an ugly fact.
Misery is a match that never goes out.
I take it that the good of mankind means the attainment, by every man, of all the happiness which he can enjoy without diminishing the happiness of his fellow men.
Teach a child what is wise, that is morality. Teach him what is wise and beautiful, that is religion!
If a little knowledge is dangerous, where is the man who has so much as to be out of danger?
Sit down before fact as a little child, be prepared to give up every conceived notion, follow humbly wherever and whatever abysses nature leads, or you will learn nothing.
Books are the money of Literature, but only the counters of Science.
It is one of the most saddening things in life that, try as we may, we can never be certain of making people happy, whereas we can almost always be certain of making them unhappy.
No delusion is greater than the notion that method and industry can make up for lack of mother-wit, either in science or in practical life.
I took thought, and invented what I conceived to be the appropriate title of 'agnostic'.
There is but one right, and the possibilities of wrong are infinite.
There is no sea more dangerous than the ocean of practical politics none in which there is more need of good pilotage and of a single, unfaltering purpose when the waves rise high.
The only freedom I care about is the freedom to do right; the freedom to do wrong I am ready to part with on the cheapest terms to anyone who will take it of me.
It is the customary fate of new truths, to begin as heresies, and to end as superstitions.
Of moral purpose I see no trace in Nature. That is an article of exclusively human manufacture and very much to our credit.
The chess-board is the world, the pieces are the phenomena of the universe, the rules of the game are what we call the laws of Nature. The player on the other side is hidden from us.
Science reckons many prophets, but there is not even a promise of a Messiah.
Surely there is a time to submit to guidance and a time to take one's own way at all hazards.
The man of science has learned to believe in justification, not by faith, but by verification.