Science must begin with myths, and with the criticism of myths.

If you know that things are bound to happen whatever you do, then you may feel free to give up the fight against them.

I have come to the conclusion that Darwinism is not a testable scientific theory, but a metaphysical research programme.

The method of science depends on our attempts to describe the world with simple theories: theories that are complex may become untestable, even if they happen to be true. Science may be described as the art of systematic over-simplification-the art of discerning what we may with advantage omit.

A rationalist, as I use the word, is a man who attempts to reach decisions by argument and perhaps, in certain cases, by compromise, rather than by violence. He is a man who would rather be unsuccessful in convincing another man by argument than successful in crushing him by force, by intimidation and threats, or even by persuasive propaganda.

It is wrong and dangerous to extol freedom by telling people that they will certainly be all right once they are free. The most we can say of democracy or freedom is that they give our personal abilities a little more influence on our well-being.

Piecemeal social engineering resembles physical engineering in regarding the ends as beyond the province of technology.