[There has been] every kind of cruelty practiced upon all sorts of people in the name of religion.

All great books contain boring portions, and all great lives have contained uninteresting stretches.

There are certain things that our age needs, and certain things that it should avoid. It needs compassion and a wish that mankind should be happy; it needs the desire for knowledge and the determination to eschew pleasant myths; it needs, above all, courageous hope and the impulse to creativeness.

I did not, however, commit suicide, because I wished to know more of mathematics.

God and Satan alike are essentially human figures, the one a projection of ourselves, the other of our enemies.

Morally, a philosopher who uses his professional competence for anything except a disinterested search for truth is guilty of a kind of treachery.

3 is prime, 5 is prime, 7 is prime, 9 is a paradox; as is a paradox why the number 1 is not prime if it has no other divisors besides himself.