Mathematics would certainly have not come into existence if one had known from the beginning that there was in nature no exactly straight line, no actual circle, no absolute magnitude.

The dyed-in-the-wool teacher takes everything seriously only with respect to his students--himself included.

Horrible experiences lead us to wonder whether the person who experiences them might not be something horrible.

Everyone needs a sense of shame, but no one needs to feel ashamed.

When I seek another word for 'music', I never find any other word than 'Venice'

Man is something that is to be surpassed.

He who fights too long against dragons becomes a dragon himself; and if you gaze too long into the abyss, the abyss will gaze into you.