“I say quite deliberately that the Christian religion, as organized in its churches, has been and still is the principal enemy of moral progress in the world.”

The fundamental concept in social science is power, in the same sense in which energy is the fundamental concept in physics.

To be able to fill leisure intelligently is the last product of civilization, and at present, very few people have reached this level.

Dogmatism is the greatest of mental obstacles to human happiness.

There are two motives for reading a book; one, that you enjoy it; the other, that you can boast about it.

How much longer is the world willing to endure this spectacle of wanton cruelty?

The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.

The only thing that will redeem mankind is cooperation.

To fear love is to fear life, and those who fear life are already 3 parts dead.

It’s easy to fall in love. The hard part is finding someone to catch you.

I believe that when I die I shall rot, and nothing of my ego will survive.

Neither a man nor a crowd nor a nation can be trusted to act humanely or to think sanely under the influence of great fear.

Your writing is never as good as you hoped, but never as bad as you feared.

Not to be absolutely certain is, I think, one of the essential things in rationality.

One of the painful things about our time is that those who feel certainty are stupid, and those with any imagination and understanding are filled with doubt and indecision.

Aristotle maintained that women have fewer teeth than men; although he was twice married, it never occurred to him to verify this statement by examining his wives’ mouths.

Men are born ignorant, not stupid; they are made stupid by education.