It is immoral not to tell.

I continue to believe that this world has no ultimate meaning. But I know that something in it has a meaning and that is man, because he is the only creature to insist on having one

We used to wonder where war lived, what it was that made it so vile. And now we realize that we know where it lives... inside ourselves.

What's natural is the microbe. All the rest-heath, integrity, purity (if you like)-is a product of the human will, of a vigilance that must never falter. The good man, the man who infects hardly anyone, is the man who has the fewest lapses of attention.

Psychology is action, not thinking about oneself.

Everyone would like to behave like a pagan, with everyone else behaving like a Christian.

Liberty is dangerous, as hard to get along with as it is exciting.