Brave men are all vertebrates; they have their softness on the surface and their toughness in the middle.

The truth is that there are no things for which men will make such herculean efforts as the things of which they know they are unworthy.

The repetition in Nature may not be a mere recurrence; it may be a theatrical encore.

Truths turn into dogmas the minute they are disputed.

We do not admire, we hardly excuse, the fanatic who wrecks this world for love of the other. But what are we to say of the fanatic who wrecks this world out of hatred of the other? He sacrifices the very existence of humanity to the non-existence of God. He offers his victims not to the altar, but merely to assert the idleness of the altar and the emptiness of the throne. He is ready to ruin even that primary ethic by which all things live, for his strange and eternal vengeance upon some one who never lived at all.

I still think sincere pessimism the unpardonable sin.

The issue is now clear. It is between light and darkness and everyone must choose his side.