A man is rational in proportion as his intelligence informs and controls his desires.

I like mathematics because it is not human and has nothing particular to do with this planet or with the whole accidental universe - because, like Spinoza's God, it won't love us in return.

Each act of cruelty is eternally a part of the universe; nothing that happens later can make that act good rather than bad, or can confer perfection on the whole of which it is a part.

Belief in God and a future life makes it possible to go through life with less of stoic courage than is needed by skeptics.

Science has made unrestricted national sovereignty incompatible with human survival. The only possibilities are now world government or death.

The use of self control is like the use of brakes on train. It is useful when you find yourself in wrong direction but merely harmful when the direction is right

The true function of logic ... as applied to matters of experience ... is analytic rather than constructive; taken a priori, it shows the possibility of hitherto unsuspected alternatives more often than the impossibility of alternatives which seemed prima facie possible. Thus, while it liberates imagination as to what the world may be, it refuses to legislate as to what the world is