Just as the performance of the vilest and most wicked deeds requires spirit and talent, so even the greatest demand a certain insensitivity which under other circumstances we would call stupidity.

There exists a species of transcendental ventriloquism by means of which men can be made to believe that something said on earth comes from Heaven.

If we make a couple of discoveries here and there we need not believe things will go on like this for ever.... Just as we hit water when we dig in the earth, so we discover the incomprehensible sooner or later.

There is no more important rule of conduct in the world than this: attach yourself as much as you can to people who are abler than you and yet not so very different that you cannot understand them.

Man is always partial and is quite right to be. Even impartiality is partial.

I have remarked very clearly that I am often of one opinion when I am lying down and of another when I am standing up.

Ideas too are a life and a world.

A clever child brought up with a foolish one can itself become foolish. Man is so perfectable and corruptible he can become a fool through good sense.

I am convinced we do not only love ourselves in others but hate ourselves in others too.

Doubt must be no more than vigilance, otherwise it can become dangerous.