Belief in a Divine mission is one of the many forms of certainty that have afflicted the human race.

I am as firmly convinced that religions do harm as I am that they are untrue.

There are infinite possibilities of error, and more cranks take up fashionable untruths than unfashionable truths.

Christ . . . said that a man who had looked after a woman lustfully had sinned as much as the man who had seduced her. How absurd!

There are three ways of securing a society that shall be stable as regards population. The first is that of birth control, the second that of infanticide or really destructive wars, and the third that of general misery except for a powerful minority.

Very few men can be genuinely happy in a life involving continual self-assertion against the skepticism of the mass of mankind, unless they can shut themselves up in a coterie and forget the cold outer world. The man of science has no need of a coterie, since he is thought well of by everybody except his colleagues. The artist, on the contrary, is in the painful situation of having to choose between being despised and being despicable.

The wise man thinks about his troubles only when there is some purpose in doing so; at other times he thinks about other things, or, if it is night, about nothing at all.