Books for all the world are always foul-smelling books: the smell of small people clings to them.

Truth is only an illusion we have forgotten is an illusion.

Those people have no real interest in a science who only begin to get excited about it when they themselves have made discoveries in it.

Christianity has taken the part of all the weak, the low, the botched; it has made an ideal out of antagonism to all the self preservative instincts of sound life; it has corrupted even the faculties of those natures that are intellectually most vigorous, by representing the highest intellectual values as sinful, as misleading, as full of temptation.

Man's maturity: to have regained the seriousness that he had as a child at play.

A soul which knows that it is loved, but does not itself love, betrays its sediment: its dregs come up.

Deception, flattering, lying, deluding, talking behind the back, putting up a false front, living in borrowed splendor, wearing a mask, hiding behind convention, playing a role for others and for oneself -- in short, a continuous fluttering around the solitary flame of vanity -- is so much the rule and the law among men that there is almost nothing which is less comprehensible than how an honest and pure drive for truth could have arisen among them.