One has to pay dearly for immortality; one has to die several times while one is still alive.

A man who is very busy seldom changes his opinions.

Whoever turns away from us might not offend us in doing so perhaps, but he certainly offends our followers.

The noble man honours in himself the powerful one, him also who has power over himself, who knows how to speak and how to keep silence, who takes pleasure in subjecting himself to severity and hardness, and has reverence for all that is severe and hard.

Whoever is related to me in the height of his aspirations will experience veritable ecstasies of learning; for I come from heights that no bird ever reached in its flight, I know abysses into which no foot ever strayed.

Many find their heart when they have lost their head.

It is perhaps just dawning on five or six minds that physics, too, is only an interpretation and exegesis of the world (to suit us, if I may say so!) and not a world-explanation.