Science may be described as the art of systematic over-simplification.

It is wrong to ask who will rule. The ability to vote a bad government out of office is enough. That is democracy.

Every discovery contains an irrational element or a creative intuition.

The only way to test a hypothesis is to look for all the information that disagrees with it.

The defence of democracy must consist in making anti-democratic experiences too costly for those who try them; much more costly than a democratic compromise

The true Enlightenment thinker, the true rationalist, never wants to talk anyone into anything. No, he does not even want to convince; all the time he is aware that he may be wrong. Above all, he values the intellectual independence of others too highly to want to convince them in important matters. He would much rather invite contradiction, preferably in the form of rational and disciplined criticism. He seeks not to convince but to arouse - to challenge others to form free opinions.

We must plan for freedom, and not only for security, if for no other reason than only freedom can make security more secure.