Sensuality often makes love grow too quickly, so that the root remains weak and is easy to pull out.

A good aphorism is too hard for the tooth of time, and is not worn away by all the centuries, although it serves as food for every epoch.

I teach you the Overman. Man is something that shall be overcome. What have you done to overcome him? ... The time has come for man to set himself a goal. The time has come to plant the seed to his highest hope.

Verily, a polluted stream is man. One must actually be a sea to take in a polluted stream without becoming impure. Behold, I teach you the superman: he is the this sea, in him can your great contempt go under.

Madness is the result not of uncertainty but certainty.

Every fact and every work exercises a fresh persuasion over every age and every new species of man. History always enunciates new truths.

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.