Do not feel envious of the happiness of those who live in a fool's paradise, for only a fool will think that is happiness.

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

The best practical advice I can give to the present generation is to practice the virtue which the Christians call love.

We do not like to be robbed of an enemy; we want someone to hate when we suffer. It is so depressing to think that we suffer because we are fools; yet, taking mankind in the mass, that is the truth.

Calculus required continuity, and continuity was supposed to require the infinitely little; but nobody could discover what the infinitely little might be.

The method of "postulating" what we want has many advantages; they are the same as the advantages of theft over honest toil.

Mathematics takes us into the region of absolute necessity, to which not only the actual word, but every possible word, must conform.