The idealist is incorrigible: if he is thrown out of his heaven he makes an ideal of his hell.

Sins are indispensable to every society organized on an ecclesiastical basis; they are the only reliable weapons of power; the priest lives upon sins; it is necessary to him that there be sinning.

Learning from one's enemies is the best way to love them, for it puts one into a grateful mood toward them.

With the strength of his spiritual sight and insight the distance, and as it were the space, around man continually expands: his world grows deeper, ever new stars, ever new images and enigmas come into view.

For some natures, changing their opinions is just as much a requirement of cleanliness as changing their clothes: for others, however, it is merely a requirement of vanity.

Moral sensibilities are nowadays at such cross-purposes that to one man a morality is proved by its utility, while to another its utility refutes it.

But eternal liveliness is what counts: what does "eternal life" matter, or life at all?