You lovers of knowledge! So what have you done out of your love of knowledge up to now? Have you already stolen and murdered so as to know how a thief and a murderer feels?

For all things are baptized at the font of eternity, and beyond good and evil; good and evil themselves, however, are but intervening shadows and damp afflictions and passing clouds.

A pair of powerful spectacles has sometimes sufficed to cure a person in love.

Not their love of humanity, but the impotence of their love, prevents the Christians of today - burning us.

Madness is not a consequence of uncertainty but of certainty.

Every attainment, every step forward in knowledge, follows from courage, from hardness against oneself, from cleanliness in relation to oneself.

The soul must have its chosen sewers to carry away its ordure. This function is performed by persons, relationships, professions, the fatherland, the world, or finally, for the really arrogant - I mean our modern pessimists - by the Good God himself.