When one gives up the Christian faith, one pulls the right to Christian morality out from under one's feet. This morality is by no means self-evident. Christianity is a system, a whole view of things thought out together. By breaking one main concept out of it, the faith in God, one breaks the whole. It stands or falls with faith in God.

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

Whoever fights monsters should see to it that in the process he does not become a monster. And if you gaze long enough into an abyss, the abyss will gaze back into you.

It is only because man believes himself to be free, not because he is free, that he experiences remorse and pricks of conscience.

There are no beautiful surfaces without a terrible depth.

The first opinion that occurs to us when we are suddenly asked about something is usually not our own but only the current one pertaining to our class, position, or parentage; our own opinions seldom swim on the surface.

I would only believe in a god who could dance. And when I saw my devil I found him serious, thorough, profound, and solemn: it was the spirit of gravity—through him all things fall. Not by wrath does one kill but by laughter. Come, let us kill the spirit of gravity!