The secret of genius is to carry the spirit of the child into old age, which mean never losing your enthusiasm.

Most vices demand considerable self-sacrifices. There is no greater mistake than to suppose that a vicious life is a life of uninterrupted pleasure. It is a life almost as wearisome and painful -- if strenuously led -- as Christian's in The Pilgrim's Progress.

We don't want to change. Every change is a menace to stability.

That we are not much sicker and much madder than we are is due exclusively to that most blessed and blessing of all natural graces, sleep.

In real life there is no such person as the average man.

Death is the only thing we haven't succeeded in completely vulgarizing.

I used to think I had no will to power. Now I perceive that I vented it on thoughts, rather than people. Conquering an unknown province of knowledge. Getting the better of a problem. Forcing ideas to associate or come apart. Bullying recalcitrant words to assume a certain pattern. All the fun of being a dictator without any risks and responsibilities.