If the perpetual oscillation of nations between anarchy and despotism is to be replaced by the steady march of self-restraining freedom, it will be because men will gradually bring themselves to deal with political, as they now deal with scientific questions.

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 besetting sin of able men is impatience of contradiction and of criticism. Even those who do their best to resist the temptation, yield to it almost unconsciously and become the tools of toadies and flatterers. "Authorities," "disciples," and "schools" are the curse of science and do more to interfere with the work of the scientific spirit than all its enemies.

Teach a man to read and write, and you have put into his hands the great keys of the wisdom-box.

The dogma of the infallibility of the Bible is no more self-evident than is that of the infallibility of the popes.

It sounds paradoxical to say the attainment of scientific truth has been effected, to a great extent, by the help of scientific errors.

Irrationally held truths may be more harmful than reasoned errors.