The scientific discovery appears first as the hypothesis of an analogy; and science tends to become independent of the hypothesis.

Our lives our guided by that general conception of the course of things which has been created by society for social purposes.

There is no scientific discoverer, no poet, no painter, no musician, who will not tell you that he found ready made his discovery or poem or picture — that it came to him from outside, and that he did not consciously create it from within.

He who truly believes that which prompts him to an action has looked upon the action to lust after it, he has committed it already in his heart.

If a belief is not realized immediately in open deeds, it is stored up for the guidance of the future.

If a man, holding a belief which he was taught in childhood or persuaded of afterwards, keeps down and pushes away any doubts which arise about it in his mind, purposely avoids the reading of books and the company of men that call in question or discuss it, and regards as impious those questions which cannot easily be asked without disturbing it - the life of that man is one long sin against mankind.

The danger to society is not merely that it should believe wrong things, though that is great enough; but that it should become credulous, and lose the habit of testing things and inquiring into them; for then it must sink back into savagery.