A man of spirit must not think of the word difficulty as so much as existing. Away with it!

One cannot demand of a scholar that he show himself a scholar everywhere in society, but the whole tenor of his behavior must none the less betray the thinker, he must always be instructive, his way of judging a thing must even in the smallest matters be such that people can see what it will amount to when, quietly and self-collected, he puts this power to scholarly use.

The fruits of philosophy are the important thing, not the philosophy itself. When we ask the time, we don't want to know how watches are made.

Do not say hypothesis, and even less theory: say way of thinking.

One's first step in wisdom is to question everything - and one's last is to come to terms with everything.

To do just the opposite is also a form of imitation.

It thunders, howls, roars, hisses, whistles, blusters, hums, growls, rumbles, squeaks, groans, sings, crackles, cracks, rattles, flickers, clicks, snarls, tumbles, whimpers, whines, rustles, murmurs, crashes, clucks, to gurgle, tinkles, blows, snores, claps, to lisp, to cough, it boils, to scream, to weep, to sob, to croak, to stutter, to lisp, to coo, to breathe, to clash, to bleat, to neigh, to grumble, to scrape, to bubble. These words, and others like them, which express sounds are more than mere symbols: they are a kind of hieroglyphics for the ear.