The ultimate court of appeal is observation and experiment... not authority.

It is not who is right, but what is right, that is of importance.

I believe that history might be, and ought to be, taught in a new fashion so as to make the meaning of it as a process of evolution intelligible to the young.

Science is organized common sense where many a beautiful theory was killed by an ugly fact.

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.

Time, whose tooth gnaws away everything else, is powerless against truth.

The only medicine for suffering, crime, and all other woes of mankind, is wisdom. Teach a man to read and write, and you have put into his hands the great keys of the wisdom box. But it is quite another thing to open the box.

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.

Irrationally held truths may be more harmful than reasoned errors.

The more rapidly truth is spread among mankind the better it will be for them. Only let us be sure that it is the truth.

Every great advance in natural knowledge has involved the absolute rejection of authority.

In scientific work, those who refuse to go beyond fact rarely get as far as fact.

Science has fulfilled her function when she has ascertained and enunciated truth.

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.

Science reckons many prophets, but there is not even a promise of a Messiah.

Science and literature are not two things, but two sides of one thing.

Of moral purpose I see no trace in Nature. That is an article of exclusively human manufacture and very much to our credit.

It is not to be forgotten that what we call rational grounds for our beliefs are often extremely irrational attempts to justify our instincts.

I am content with nothing, restless and ambitious... and I despise myself for the vanity, which formed half the stimulus to my exertions. Oh would that I were one of those plodding wise fools who having once set their hand to the plough go on nothing doubting.

The doctrine that all men are, in any sense, or have been, at any time, free and equal, is an utterly baseless fiction.

The ultimate court of appeal is observation and experiment... not authority.

All truth, in the long run, is only common sense clarified.

Teach a child what is wise, that is morality. Teach him what is wise and beautiful, that is religion!

Economy does not lie in sparing money, but in spending it wisely.

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.

Nothing can be more incorrect than the assumption one sometimes meets with, that physics has one method, chemistry another, and biology a third.

The scientific spirit is of more value than its products, and irrationally held truths may be more harmful than reasoned errors.

I took thought, and invented what I conceived to be the appropriate title of 'agnostic'.

In science, as in art, and, as I believe, in every other sphere of human activity, there may be wisdom in a multitude of counsellors, but it is only in one or two of them.

The scientific imagination always restrains itself within the limits of probability.

Science commits suicide when it adopts a creed.

Ecclesiasticism in science is only unfaithfulness to truth.

My business is to teach my aspirations to confirm themselves to fact, not to try and make facts harmonize with my aspirations.

It is the customary fate of new truths, to begin as heresies, and to end as superstitions.

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 slavery can be abolished without a double emancipation, and the master will benefit by freedom more than the freed-man.

Books are the money of Literature, but only the counters of Science.

The man of science has learned to believe in justification, not by faith, but by verification.

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.

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.

My experience of the world is that things left to themselves don't get right.

The great thing in the world is not so much to seek happiness as to earn peace and self-respect.

It is because the body is a machine that education is possible. Education is the formation of habits, a superinducing of an artificial organization upon the natural organization of the body.

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.

Misery is a match that never goes out.

Size is not grandeur, and territory does not make a nation.

Science is nothing, but trained and organized common sense.

The results of political changes are hardly ever those which their friends hope or their foes fear.

The Bible has been the Magna Carta of the poor and of the oppressed.