A Note on the Influence of Mach’s Psychology in the Sensory Order

Here are a couple of extracts from Giandomenica Becchio’s paper:

In the Preface of The Sensory Order, Hayek stated that this book was based on his readings in psychology during 1919–1920, when he was still a young student in Vienna interested in both psychology and economics. Among many others, Hayek explicitly cited Mach’s influence on him. Hayek’s contacts with the lively Viennese milieu during the 1920s and 1930s had a fundamental role in the story of the use of Mach in Hayek’s book. As Hayek himself explained, Mach had a great influence on Viennese students and scholars until the 1930s, because he represented ‘‘the only source of arguments against a metaphysical and nebulous attitude’’ that was spreading among scientists (Blackmore, Itagaki, & Tanaka, 2001, p. 124). The use of Mach’s philosophy as a tool against any metaphysical attitude was particularly strong inside the Vienna Circle, where scholars like Otto Neurath and Rudolph Carnap had founded the Ernst Mach Society (Verein Ernst Mach, 1927) to support their movement and to link Mach’s empiricism to their philosophical approach,which they later named ‘‘logical positivism’’ (Blumberg & Feigl, 1931). Hayek strongly criticized the Vienna Circle’s philosophical approach: he mainly rejected Neurath’s physicalism (the belief that all science ultimately reduces to the laws of physics, Neurath, 1931; Caldwell, 2004), even if he showed some interest in Carnap’s logical system (Carnap, 1928). When Hayek introduced the system of multiple classification in The Sensory Order, he cited Carnap as the one who provided ‘‘a somewhat similar statement of the problems of the order of sensory qualities’’ (Hayek, 1952, p. 51). Nevertheless, in the mid-1930s, when Carnap officially subscribed to Neurath’s physicalism, it culminated in the project of the unification of science (Stadler, 2001).1 Hayek’s aversion arose: From the fact that we shall never be able to achieve more than an ‘explanation of the principle’ by which the order of mental events is determined, it also follows that we shall never achieve a complete ‘unification’ of all sciences in the sense that all phenomena of which it treats can be described in physical term. (Hayek, 1952, p. 191)

And in the following footnote he specifically named both Carnap and Neurath: their physical language, since it refers to the phenomenal or sensory qualities of the objects, is not ‘‘physical’’ at all. Their use of this term rather implies a metaphysical belief in the ‘‘ultimate reality’’ and constancy of the phenomenal world for which there is little justification. (ibid.) In this passage Hayek accused them of having dropped their original antimetaphysical attitude – mediated through Mach – to propose a new form a metaphysical belief, based on the reduction of any reality to the empirical realm. Hayek’s j’accuse is significant: for 30 years the philosophers of the Vienna Circle claimed Mach’s philosophy as one of the main sources of their aversion to metaphysics and a pillar of their philosophical approach based on a new form of positivism.2 In the International Encyclopedia of Unified Science, Joergensen explained the three common traits between ‘‘Mach’s positivism’’ and the Vienna Circle philosophy: the idea that ‘‘human knowledge is a biological phenomenon’’; the rejection of any form of ‘‘thing-in-itself’’ (and for that matter, of any form of Kantianism) and the overlap between physical reality and physical elements (Joergensen, 1951, p. 853). To explain the link between Mach and Hayek on the one hand and Hayek’s aversion to the logical positivism (apparently and ‘‘officially’’ rooted in Mach’s philosophy) on the other hand, we need to consider what Hayek meant when he mentioned Mach’s influence in The Sensory Order.

As Hayek himself stated in the Preface of The Sensory Order, psychology is essentially ‘‘dealing with the problems of the methods of the social sciences [a] concern with the logical character of social theory’’ (Hayek, 1952, p. v). From a broader perspective, Hayek’s aversion to reductionism can be seen as the reverse side of the struggle for individualism he started in the late 1930s with the publication of ‘‘Economics and Knowledge’’ and culminated in Individualism and Economic Order (1949), which was published just few years before his decision to revise and finally publish The Sensory Order. During the early 1950s while working on The Sensory Order, Hayek composed ‘‘Within Systems and About Systems,’’ which dealt with the possible knowledge of our mental processes and with the relationship between knowledge and the external environment.

In the early 1930s, Hayek edited Carl Menger’s Collected Works (in German): he also wrote a well-known presentation of Menger’s thought and work. It was published in Economica, and it represented the introduction of Menger to the English-speaking world (Hayek, 1934). In this essay, Hayek stressed the centrality of individualism in Menger’s approach when he had described how markets work and how economic agents behave when they make an economic decision. In the same period Hayek started to work on the link between economic choice and individual knowledge, which culminated in his well-known paper Economics and Knowledge.

From Economics and Knowledge onward, Hayek introduced psychology into economics to explain the dynamics of a society in an individualistic perspective. In this view, Hayek’s decision to work back on revise and publish The Sensory Order can be regarded as the final step of his research project on the nature of individual choice.

After having described the role of knowledge in individual plans and the following mechanism of the market, as well as the use of knowledge in a competition as a discovery process, Hayek described the nature of human mind. The Sensory Order can be seen as Hayek’s tool to show how people know the internal and external reality, how they form their knowledge and how they can share it to make their own plans and coordinate them.

From Hayek’s presentation of Menger’s thought as a stronghold of individualism (1934) to the publication of The Sensory Order (1952), Hayek’s work can be regarded as a tentative to investigate how society works from an individualistic point of view and how the human mind knows from an antireductionist perspective; in opposition to a new kind of holistic and reductionist approach, supported by the predominant position inside the Vienna Circle, mainly by Neurath and Carnap.

The role of Mach in this story is important. Both Hayek and Neurath/Carnap considered Mach the most influential anti-metaphysical thinker. Nevertheless, Neurath/Carnap accepted Mach’s reductionism in psychology as well as his final philosophical approach as a direct development of his psychology. Furthermore, the unity between physics and psychology (between physical and sensorial orders) in Mach’s thought also opened the way to the Vienna Circle’s ideal of a unified science (from physics to social sciences), never accepted by Hayek.

Mach’s influence on Hayek is more complex, though.

Hayek started from Mach’s psychological inquiry, which was influenced by Kant’s research on the nature of knowledge; but, as Mach had refused the final stage of Kantism (the Dich an sich as a metaphysical residuals), Hayek refused the final stage of Machian philosophy (the isomorphism between physical and mental realm as a form of reductionism). Hayek refused Mach’s destruction of ‘‘the conception of elementary and constant sensations as ultimate constituents of the world’’ and he restored ‘‘the necessity of a belief in an objective physical world which is different from that presented to us by our senses’’ (Hayek, 1952, p. 176, 8.37). In a certain sense, Hayek went back to a sort of Kantian dualism, without introducing a negative concept, like Ding an sich. Hayek wrote: The conclusion towhich our theory leads is thus that to us not onlymind as a whole but also all individual mental processes must forever remain phenomena of a special kind, which. Although produced by the same principles which we know to operate in the physical world, we shall never be able fully to explain in terms of physical laws. (Hayek, 1952, p. 191)

It will derive its statements about some mental processes from its knowledge about other mental process, but it will never be able to bridge the gap between the realm of the mental and the realm of the physical. Such a verstehende psychology, which starts from our given knowledge of mental processes, will, however, never be able to explain why we must think thus and not otherwise, why we arrive at particular conclusions (Hayek, 1952, p. 192).