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.

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

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.

Freedom and order are not incompatible... truth is strength... free discussion is the very life of truth.

Ecclesiasticism in science is only unfaithfulness to truth.

Science is simply common sense at its best, that is, rigidly accurate in observation, and merciless to fallacy in logic.

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.