I could never have known so well how paltry men are, and how little they care for really high aims, if I had not tested them by my scientific researches. Thus I saw that most men only care for science so far as they get a living by it, and that they worship even error when it affords them a subsistence.

Everybody wants to be somebody; nobody wants to grow.

All truly wise thoughts have been thought already thousands of times; but to make them truly ours, we must think them over again honestly, until they take root in our personal experience.

God help us -- for art is long, and life so short.

Animals, we have been told, are taught by their organs. Yes, I would add, and so are men, but men have this further advantage that they can also teach their organs in return.

He who has a task to perform must know how to take sides, or he is quite unworthy of it.

He who would reproach an author for obscurity should look into his own mind to see whether it is quite clear there. In the dusk the plainest writing is illegible.