The first article republished in Studies in Philosophy, Politics and Economics, "Degrees of Explanation," originally published in 1955, was largely consistent with Popper's methodology. Hayek embraced Popper's "hypothetico-deductive" approach to science: "The conception of science as a hypothetico-deductive system has been expounded by Karl Popper in a manner which brings out clearly some very important points." Here, as elsewhere in his work, Hayek distinguished between the facts of the natural and social sciences primarily on the basis of their complexity.

I referred above to the Popperian school as a school, and yet it was not until I came to Sydney from London that I fully realised the extent to which I had been in a school. I found, to my surprise, that there were philosophers influenced by Wittgenstein or Quine or Marx who thought that Popper was quite wrong on many issues, and some who even thought that his views were positively dangerous. I think I have learnt much from that experience. One of the things that I have learnt is that on a number of major issues Popper is indeed wrong, as is argued in the latter portions of this book. However, this does not alter the fact that the Popperian approach is infinitely better than the approach adopted in most philosophy departments that I have encountered.

A theory that explains everything, explains nothing.

When we enter a new situation in life and are confronted by a new person, we bring with us the prejudices of the past and our previous experiences of people. These prejudices we project upon the new person. Indeed, getting to know a person is largely a matter of withdrawing projections; of dispelling the smoke screen of what we imagine he is like and replacing it with the reality of what he is actually like.

Leadership is solving problems. The day soldiers stop bringing you their problems is the day you have stopped leading them. They have either lost confidence that you can help or concluded you do not care. Either case is a failure of leadership.

The deepest, the only theme of human history, compared to which all others are of subordinate importance, is the conflict of skepticism with faith.

To be ignorant of the past is to remain a child.

Ignorance is not a simple lack of knowledge but an active aversion to knowledge, the refusal to know, issuing from cowardice, pride or laziness of mind.

Why do I think that we, the intellectuals, are able to help? Simply because we, the intellectuals, have done the most terrible harm for thousands of years. Mass murder in the name of an idea, a doctrine, a theory, a religion — that is all our doing, our invention: the invention of the intellectuals. If only we would stop setting man against man — often with the best intentions — much would be gained. Nobody can say that it is impossible for us to stop doing this.

There are uncertain truths — even true statements that we may take to be false — but there are no uncertain certainties. Since we can never know anything for sure, it is simply not worth searching for certainty; but it is well worth searching for truth; and we do this chiefly by searching for mistakes, so that we have to correct them.