“The development of economics as a science which is always based on human beings, the creative actors and protagonists in all social processes and events (the subjectivist conception), is undoubtedly the most significant and characteristic contribution made by the Austrian School of economics, founded by Carl Menger. In fact Menger felt it vital to abandon the sterile objectivism of the classical (Anglo-Saxon) school whose members were obsessed with the supposed existence of external objective entities (social classes, aggregates, material factors of production, etc.). Menger held that economists should instead always adopt the subjectivist view of human beings who act, and that this perspective should invariably exert a decisive influence on the way all economic theories are formulated, in terms of their scientific content and their practical conclusions and results.”

Gary Becker (1991). "Milton Friedman." In: Edward Shils, ed. Remembering the University of Chicago: Teachers, Scientists and Scholars. Chicago: University of Chicago Press, pp. 140-6

Hayek's Journey: The Mind of Friedrich Hayek (2003)

Source: Toward a New Sustainable Economy, 2008, p. 46

Source: Nationalism and Culture (1937), Ch. 1 "The Insufficiency of Economic Materialism"
Context: Every process which arises from our physical being and is related to it, is an event which lies outside of our volition. Every social process, however, arises from human intentions and human goal setting and occurs within the limits of our volition. Consequently, it is not subject to the concept of natural necessity. … We are here stating no prejudiced opinion, but merely an established fact. Every result of human purposiveness is of indisputable importance for man's social existence, but we should stop regarding social processes as deterministic manifestations of a necessary course of events. Such a view can only lead to the most erroneous conclusions and contribute to a fatal confusion in our understanding of historical events.
It is doubtless the task of the historian to trace the inner connection of historical events and to make clear their causes and effects, but he must not forget that these connections are of a sort quite different from those of natural physical events and must therefore have quite a different valuation.

Meeting the Challenges of Electronic Business” in Muscat, Oman, October 9, 2000.

1970's, Every Man an Artist: Talks at Documenta 5', 1972

Be Here Now (1971)
Context: Before March 6th, which was the day I took Psylocybin, one of the psychedelics, I felt something was wrong in my world, but I couldn't label it in any way so as to get hold of it. I felt that the theories I was teaching in psychology didn't make it, that the psychologists didn't really have a grasp of the human condition, and that the theories I was teaching, which were theories of achievement and anxiety and defense mechanisms and so on, weren't getting to the crux of the matter.
My colleagues and I were 9 to 5 psychologists: we came to work every day and we did our psychology, just like you would do insurance or auto mechanics, and then at 5 we went home and were just as neurotic as we were before we went to work. Somehow, it seemed to me, if all of this theory were right, it should play more intimately into my own life. I understood the requirement of being "objective" for a scientist, but this is a most naive concept in social sciences as we are finding out....
Something was wrong. And the something wrong was that I just didn't know, though I kept feeling all along the way that somebody else must know even though I didn't. The nature of life was a mystery to me. All the stuff I was teaching was just like little molecular bits of stuff but they didn't add up to a feeling anything like wisdom. I was just getting more and more knowledgeable.

Hayek's Journey: The Mind of Friedrich Hayek (2003)

Source: The Human Side of Enterprise (1960), p. 16 (p. 23 in 2006 edition)