Some scientists find, or so it seems, that they get their best ideas when smoking; others by drinking coffee or whisky. Thus there is no reason why I should not admit that some may get their ideas by observing, or by repeating observations.

It is often asserted that discussion is only possible between people who have a common language and accept common basic assumptions. I think that this is a mistake. All that is needed is a readiness to learn from one's partner in the discussion, which includes a genuine wish to understand what he intends to say. If this readiness is there, the discussion wrighteous stupidityill be the more fruitful the more the partner's backgrounds differ.

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.

A theory is just a mathematical model to describe the observations.

If we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them.

I think that we shall have to get accustomed to the idea that we must not look upon science as a 'body of knowledge,' but rather as a system of hypotheses; that is to say, as a system of guesses or anticipations which in principle cannot be justified, but with which we work as long as they stand up to tests, and of which we are never justified in saying that we know they are 'true' or 'more or less certain' or even 'probable.'

I have learned more from Hayek than from any other living thinker, except perhaps Alfred Tarski - but not even excepting Russell.