Here is Walt Weimer’s brief but valued contribution to Hayek in Mind. Wiemer did so much to bring Hayek’s philosophical psychology to the wider world – and for that we are deeply indebted to him. It’s still really worth checking out Weimer’s work.

Occasionally I am asked how I came to the work of Friedrich Hayek and why I promoted it (to a mainly psychological audience) through conferences and writings in the 1970’s and 1980’s during the period when I was able to indulge my hobby of studying interesting questions as an “almost” or part-time academic (Weimer, 1974; 1982). Usually it is assumed that I was a psychologist who came across The Sensory Order (Hayek, 1952) and saw its relevance to the “cognitive revolution” then in progress. While partly true, I was never primarily a psychologist – I have always been a student of interesting problems and I do not recognize the sanctity of academic or bureaucratic boundaries. The only problem that consumes me is the nature of knowledge and its acquisition and use. My autobiography would be titled “What Little I Know” in contrast to a physicist of the ‘80’s famous for “What Little I Remember.” I am, in short, primarily an evolutionary epistemologist, as the field has been pioneered by Don Campbell. Hayek had studied the same issues and had similarly been an outsider, a “marginal man,” who was primarily an evolutionary epistemologist usually mistaken for either an economist or political philosopher.


Cognitive Opening and Closing: Toward an Exploration of the Mental World of Entrepreneurship

Here is Thierry Aimar’s intro to his paper for Hayek in Mind.

Contemporary analysis usually divides games of chance into three dimensions. In Machina and Schmeidler’s (1992) terms, this division can be viewed based on the example of an urn containing 90 balls of different colors, out of which an agent pulls a ball, of which he must ex ante guess its color to achieve a predetermined gain. If the agent knows that the number of red, white, and black balls is the same (30), he finds himself in a situation of risk: He knows the possible consequences and the probability distributions, that is, he has one in three chances of getting a ball of any particular color. However, if he knows that these balls are red, white, and black, but in indefinite proportions, he is confronted with situations qualified as uncertainty: The consequences are known, but the probability distributions are not. Yet again, if the agent knows there are 90 balls of different colors in the urn but does not know how many of these colors there are, he is in a state of incomplete information: The agent is unable to define the list of possible outcomes (situation of ambiguity) and can expect some surprises identifiable ex ante, as states of nature are identifiable. An extra dimension may be added to this distinction: If the agent has himself placed 30 red balls in the box, but he does not know what other elements of indefinite character and number there are in the box, nor the structure of gains or losses associated with various results, then we can consider that the agent is in a position of ignorance. Not only is he unable to define the list of consequences of the game, but he also does not know the distribution of events. The agent is able to define what he knows, but unlike the three previous cases, he cannot determine the scope and nature of what he ignores. The surprise is necessarily unexpected in the sense that the agent is unable to identify ex ante the possible states of nature. It is in this latter perspective that Kirzner (1973, 1979, 1982) argues that market actors face a phenomenon of ‘‘genuine ignorance,’’ reflecting their inability to know all the opportunities for exchange or profit available in an economy. At any point in time, each individual perceives only fragmentary aspects of social reality in which he participates, and not its other facets. Each exchange is made in ignorance of other exchanges performed at the same time; thus, there is no common knowledge of prices and no actor can perceive the whole. In a monetary economy, the consequences of these independent exchanges are mutually dependent. The implications of this genuine ignorance on the coordination of activities are thus considerable. Using the example of Schmeidler and Machina’s urn (1992) from the time when the consequences of a draw for each individual depend on the (unknown) number of elements (of unknown character) deposited in the ballot box by an (unknown) number of (unknown) people, the ability of such a game to produce a balance is at least questionable. The stakes of this phenomenon of ignorance compel us to identify its sources. These are not found in any complexity of information, neither in the cost of its acquisition nor in its treatment (deliberation) from a perspective of bounded rationality. They come from a more fundamental phenomenon of dynamic subjectivism. According to authors such as Kinder (1973, 1979, 1997) and Lachmann (1977, 1986), agents’ preferences, endowments, knowledge, and strategies should be defined as personal, unique. Therefore, each individual is a priori ignorant of how others evaluate goods and services. Economic analysis is not therefore based on a perfect, or even sufficient knowledge of actors to coordinate their activities. The diversity of actors’ preferences, interpretations, and expectations would certainly not be a problem if they were constants. A process of trial and error would lead to new learning, opening onto a price structure that would allow coordination. But this is in fact not the case because the individual performances would change continuously, according to an endogenous process, ultimately explained by ignorance or internal self-ignorance (Aimar, 2008a). As Hayek (1951a, 1951b) explained, the actor can only partially perceive the existing opportunities for satisfaction, for reasons related to the organization of the human brain and the tacit characteristic of knowledge. His conscious choices being ignorant of a portion of his subjectivity, he makes mistakes, expressed by disappointment with satisfaction. He undergoes a de facto internal discoordination, forcing him to change his representations to make his beliefs conform to the reality of his interior environment. But changing choices results in transforming his internal environment and de facto creates new unknown areas. The mind, constantly evading the consciousness’s desire to fully absorb it, makes the process of self-discovery never-ending. Thus, market discoordination, the result of genuine ignorance, is finally but an internal discoordination, consequence of a phenomenon of self-ignorance. It was around this phenomenon of genuine ignorance and its perverse effects on coordination between individuals that Kirzner introduced the theme of entrepreneurship. The entrepreneurial function, driven by the incentive of profit, is to discover unperceived opportunities. Mobilizing qualities of alertness, reflected in cognitive openness, it reveals previously hidden information. Through his discoveries being translated into new money transactions, the entrepreneur socializes his knowledge and contributes to pulling market activities toward coordination. He goes beyond reducing ignorance; he transforms ignorance into uncertainty. But according to Kirzner, a parallel mission of the entrepreneur is to organize already discovered opportunities in the form of firms’ production plans, in order to protect them from risk of obsolescence resulting from the volatility of data. In a dynamic world, discovery and exploitation of opportunity are then the two faces of entrepreneurship. The author argues that these two dimensions may be contradictory in the entrepreneurial mind. As much as discovery implies a cognitive opening to the outside, all exploitation of discovered opportunities is accompanied by elements of mental rigidity. These take the form of cognitive closure, thus opposing the entrepreneur’s perception of new opportunities. The aim of this contribution is to illuminate by the structure of this contradiction by economic analysis, to provide the means to verify it through experimental economics and to consider its extensions in terms of neuroeconomics. Our plan is this: After explaining the basics of the theory of entrepreneurship and the elements that determine its duality, we will define the bases for an experimental protocol likely to support our thesis of an opposition in the cognitive field between the relative strengths of discovery and the exploitation of opportunities in the entrepreneurial mind. The last section forms the conclusion.


Hayek’s Post-Positivist Empiricism: Experience Beyond Sensation

The intro from Jan Willem Lindemans’ paper:

The philosophical foundations of Hayek’s works are not beyond dispute (Gray, 1984, Kukathas, 1989, Caldwell, 1992, Hutchison, 1992): was Hayek a rationalist or an empiricist; did he follow Kant or Hume, Mises or Popper? Difficulties arise because these questions touch upon social theory, political philosophy, methodology and epistemology. Moreover, on different occasions, Hayek (intentionally) gave different definitions and evaluations of already complicated views such as ‘rationalism’ and ‘empiricism’. In this paper, I try to shed some light on the rationalism/empiricism issue by focusing on epistemology, where this issue really belongs. The debate there is mainly about the sources of knowledge (e.g., Markie, 2008). Empiricists argue that experience is the source of all our knowledge. This view was held by John Locke (1632-1704) and David Hume (1711-1776) but its roots go back to Francis Bacon (1561-1626) and even further to the ancient Greek Empiricist school in medicine (founded in the third century B.C. by Philinos of Kos or Serapion of Alexandria) and Aristotle (384-322 B.C.). In contrast with his teacher Plato, Aristotle believed in the ‘induction’ (epagōgē) of general knowledge from particular observations. I will not have the space here to relate Hayek’s ideas to this long history of empiricism. But I will try to refer to David Hume now and then, because Hayek was a great admirer of Hume’s social and political philosophy and Hayek’s ‘Humeanism’ is extensively discussed. I will also get back to the less well known Empiricist school in medicine, because it has a very special conception of ‘experience’ which I believe to be useful to the discussion. In contrast with empiricism, rationalism or ‘apriorism’ is the idea that some knowledge is independent of experience or ‘a priori’. Traditionally, this meant that knowledge is based on rational intuition, or embedded in our rational nature or the structure of the mind. If knowledge is embedded in our mind or nature, it is ‘innate’, which is why philosophers speak of ‘innatism’ or ‘nativism’. Since this was Immanuel Kant’s (1724-1804) view, it is often called ‘Kantianism’. I will also use the term ‘Kantianism’ rather than ‘rationalism’ because Hayek most often defines the latter as the false view that social phenomena are rationally designed, which is a completely different issue. Kantianism goes back to the ‘innate ideas’ of René Descartes (1596-1650) and the anamnesis of ideas in Plato’s philosophy (429-347 B.C.). Many scholars have tried to position Hayek in the Kantianism/empiricism debate. Most scholars would probably agree with Connin (1990, p. 301) that “Hayek’s theory of knowledge is undoubtedly Kantian” (see also Feser, 2006, p. 300). However, many also understand that there is more to it (Caldwell, 2004, p. 273). Since ‘experience’ is undeniably a basic concept in Hayek’s epistemology, some believe that his epistemology is a kind of synthesis between Kantianism and Humean empiricism (Horwitz, 2000, p. 25). De Vecchi (2003, p. 152) is less optimistic and says that “there is an unresolved tension between empiricism and anti-empiricism within the theory of the process of the formation of knowledge set out in The Sensory Order”. Moreover, some have made the link with ‘evolutionary epistemology’ (Bartley, 1987, p. 21; Gray, 1984; Kukathas, 1989; Dempsey, 1996; Vanberg, 2002). However, scholars have rarely wondered how Kantianism, empiricism and evolutionism can be reconciled, and, more importantly, what ‘empiricism’ and ‘experience’ mean in such a context. Just as there are as many ‘rationalisms’ as there are interpretations of the term ‘reason’, there are as many ‘empiricisms’ as there are interpretations of the term ‘experience’. In this paper, I will reconstruct Hayek’s epistemology based on a careful reading of The Sensory Order and some related writings. I will argue that Hayek’s epistemology is best characterized as a type of ‘post-positivist empiricism’. In the first paragraph, I review Hayek’s neurophysiological explanation of the mind in The Sensory Order. Hayek shows how the nervous system can perform the acts of classification characteristic of the working of the mind. Because the synaptic connections embody a kind of knowledge independent of ‘sense experience’, Hayek is not a ‘sensationalist empiricist’. The second paragraph discusses Hayek’s theory of the formation of synaptic connections. Connections are formed on the basis of what I will call ‘Hayek’s learning rule’, which boils down to the familiar idea that neurons that fire together wire together. Since this means that the knowledge embodied in the synaptic connections is in a sense the result of ‘experience’, be it ‘pre-sensory experience’ rather than ‘sense experience’, Hayek is an empiricist after all, but one of the ‘post-positivist’ kind. In the third paragraph, I analyze Hayek’s views on the evolution of the nervous system and the behavior it generates. There appear to be two kinds of ‘experience’ at the basis of the synaptic connections: ‘experience of the individual’ and ‘experience of the race’. Because Hayek denies that all knowledge is due to ‘experience of the individual’, he is not an ‘individualist empiricist’. However, since ‘experience of the race’ is also ‘experience’, he is again an empiricist in the wider sense. What Hayek failed to notice is that experience of the race is ‘post-sensory’ rather than ‘pre-sensory’ and also in other aspects very different from individual experience. I will call it a kind of ‘selective experience’, which I contrast with ‘inductive experience’. Some links with Donald Campbell’s ‘evolutionary epistemology’ are explored. In the last paragraph, I consider Campbell’s idea that all increases in knowledge are due to selection and make some suggestions for future research.


The Emergence of the Mind: Hayek’s Account of Mental Phenomena as a Product of Spontaneous Physical and Social Orders

Gloria Zúñiga y Postigo’s intro from her excellent paper.

Friedrich Hayek’s social theory is well known for his articulation of the paradigm of spontaneous orders that challenges the traditional distinction between what is natural and what is artificial. The problem that Hayek saw is that language and other social objects do not fall under either heading completely. Language is, for example, seen as natural since it was not designed by man. At the same time, man has imposed rules of grammar on natural languages as these became formalized and documented. From this perspective, language falls under the category of artificial too. This distinction thus fails in its application not only to language, but also to any other object that is, as Hayek puts it, the result of human action, but not of human design.  The paradigm of spontaneous orders, which applies to all social objects, has thus become the hallmark of Hayek’s social theory.


C. S. Peirce and F. A. Hayek on the Abstract Nature of Sensation and Cognition

Here is the intro to Jim Wibble’s fascinating paper, the full version available here.

When exploring ideas on philosophy of science and economic methodology, one of the most unusual articles that one can encounter is Hayek’s well-known piece, “The Primacy of the Abstract”. In a note in the article, Hayek tells us that he had thought of another title but it Awould not have had the shock effect which is the merit of the phrase chosen.[i] What Hayek wanted to convey with the title was the intellectual novelty of the positions argued. Without getting into the details of his position, Hayek maintains that all sensation is preceded by mental operations of abstraction. He had expressed his views on the subject nearly two decades earlier in a much larger work. His views on the primacy of the abstract had already appeared in The Sensory Order (1952). In that book, Hayek had taken the position that the abstract nature of sensation and cognition was supported by what we would now call the neuroscience of his time. In other words, Hayek thought that the neurophysiological evidence concerning how human sensation and cognition function provided an empirical basis for questioning prevailing empiricist theories and philosophies of how those functions worked. Various versions of empiricism dominated much of science at that time. Also the empiricist psychology of abstract ideas from the British associationist school was widely known in both early 20th century philosophy and psychology. Among other things, Hayek was conveying his sharp disagreement with the prevailing empiricist conceptions of how abstract ideas were created and how science was understood. Such a different view of how human knowing functions also has profound implications for understanding how society can be governed, for how the economy works, and for understanding the evolutionary limits on human knowing in economic processes.

Since Hayek’s title, “The Primacy of the Abstract”, had its intended shock effect on this author, it created an intellectual sensitivity for like ideas.[ii] As it turns out, another intellect had come to a similar position on cognition and abstraction decades earlier than Hayek. The purpose here is not to identify a precursor as such, but rather to acknowledge both the similarities and the differences in their views. The other figure is the American scientist, mathematician, and philosopher Charles Sanders Peirce. From a couple of references that Hayek has made to Peirce’s writings and the fact that Hayek’s good friend, Karl Popper, also knew of Peirce’s writings, it appears that Hayek must have read some of the volumes of Peirce’s Collected Papers. As quoted at the beginning of the paper, Popper called Peirce “one of the greatest philosophers of all time.” Peirce and Hayek were inquiring minds whose interests seem to range over many of the same disciplines but with varying degrees of intensity. Peirce may have had a greater knowledge of astronomy, mathematics, and philosophy while Hayek had a deeper awareness of economics, linguistics, psychology, and political philosophy. Peirce like his well-known father Benjamin, also had a keen interest in economics, especially mathematical economics. Peirce the son kept in touch with economics through his life-long acquaintance Simon Newcomb whose second discipline of interest after astronomy was economics.[iii] Newcomb was a prominent antagonist of the founders of the American Economics Association in the late 1880s. Newcomb, who eventually joined the AEA, opposed the expansive view of government proposed by AEA founders such as Richard Ely and Edmund James. Peirce was also kept aware of developments in psychology by his lifelong friend William James. Hayek certainly seems to have been greatly aware of James’s contributions to cognitive psychology. So here is another avenue of connection between Peirce and Hayek.

[i] The alternative title would have been the primacy of the general (Hayek, 1969 [1978], p. 35).

[ii] Readers may want to know that the author was one of two economics graduate students that attended the Penn State conference on cognitive psychology in May of 1977 where Hayek’s The Sensory Order was given a central place in the sessions and the discussions. William Butos was the other student. We heard Walter Weimer (1982) deliver his long keynote address and appraisal of The Sensory Order and Hayek’s (1982) response. Weimer thought that Hayek’s views were more psychological and thus closer to Thomas Kuhn’s view of science than those of Popper or Lakatos. In the discussion which followed, I asked Hayek whether that was so. His response was I am still a Popperian (Weimer and Hayek, 1982, p. 323). Weimer was a member of the dissertation committees for both Butos and the author.

[iii] For many of these details consult Moyer’s (1992) biography.


Fuster’s “Prólogo” to Hayek’s El Orden Sensorial

Here is a translation I commissioned by José Villavicencio of Joaquin Fuster’s “Prólogo” to F. Hayek El Orden Sensorial. Unión Editorial, S.A., Madrid, pp 11-23, 2004.



Salzburg, May 17, 1976

Dear Professor Fuster,

Thank you very much for your kind letter dated the 3rd of this month and that I have in my possession without having had the time to answer because I needed to make a visit to Vienna. It is always a great pleasure when, for long periods of time, I learn that someone is interested or remembers my Sensory Order. I have not seen any specific reaction to my way of thinking, even though it is a fact that it was recently republished for a second time indicating then that there is someone reading it…

Yours truly,

F.A. Hayek

In order to understand the intellectual roots of The Sensory Order, I am inviting the reader to visit Vienna, the Vienna of the last century’s 2nd decade, where and when the author wrote this work’s first draft. There is the beginning of the prestigious positivist school of philosophy, whose epistemology Hayek adopted in order to clarify the philosophical base of the mind. For positivist psychologists of the period, the mind is accessed through the senses, and thus, that’s what he begins to do, using empiricism, as it was the usage in vogue by the great physiologist-psychologist of the XIX century (e.g., Mach, Helmholtz, Wundt, James Müller). Just beyond the entrance to the senses is perception, the cognitive faculty that represents the world that surrounds us in the form of objects, animate and inanimate beings, and structures and physical occurrences, all with their respective dimensions of time and space. Perception, for the empiricists and the young Hayek, is the preferred way of the mind. According to them, if we understood the physiology of how we understand the world around us, we would understand the structure and the functions of the mind in the brain. The theoretical psychologists of the moment, and thus Hayek in the beginning build their theories of perception starting from basic elements of sensation, what Mach (1885) calls “the pure nucleus of sensation”. From here on, in apposition to primary sensations, the primary structures of perception begin to be formed, and these, in apposition too, form the more elaborate structure of the mind. The mental panorama of perception becomes a type of mirror or group of mirrors that reflect the exterior world. Thus, the mental world reflects the exterior world as a mosaic perception of itself. From this comes the so-called psychology of “mosaic”. It is a vision somewhat static of things that do not take into account the huge informative power of perceiving that resides in the almost limitless combination of the aforementioned basic elements of elemental sensation. Hayek quickly abandoned this static and restrictive vision of perception for a more dynamic vision of that function and more in line with the principles of interaction between perception and memory, fundamental with the principle—previously espoused by Helmholtz—that stipulated that perception sprouts from memory, and vice-versa, memory from perception. We not only remember that we perceive, but we perceive because we remember. Even more, for both, memory and perception, the “rule” is a rule of relations. Objects from both define themselves by a relation of spatial and temporal associations between elements of lesser rank to the former elements. It is in the power of the combination, to know, of the relation, where Hayek finds the key of perception, and thus, the sensory order. He does it forcing the psychology “of mosaic” to take a Copernican turn around. In the new psychology of perception he proposes, there are neither elemental sensations nor sensational nucleuses à la Mach. All perception, even the more elemental, are based on the relations or contiguousness or simultaneity between the stimuli or impulses to which the object has been subject in its own past or in the past of the species. It is here where Hayek finds the fulcrum for the Copernican turn: in the evolution of species and the individual, to know, in phylogeny and ontogeny. There is nothing new in the world of the senses. Everything we feel and perceive is of associative character, is the aggregate of relations that have been formed between stimuli that have occurred at the same time and at the same historical places of the species or the individual organism. At the lowest levels, the primary sensations are based on simple relationships that in the course of evolution have established relationships of contiguousness or spatial or temporal continuity. This is how the temporal sensors and the sensory receptors of the optical thalamus and the cerebral cortex are formed. These structures constitute, to put it this way, the memory of the species, the filetic memory or evolutionary, which was formed during the “night of time” in order to better adapt the species to the vicissitudes of the environment. Above those lowest levels of the sensory order, presumably in the so called cortex of association, the systems of relations are being formed between stimuli, let’s say it now, the networks of perceptive individual memory (in a psychological plane, Hayek calls them maps) that store in its structure the memory of the individual, plastic, dynamic and open to the future, subject to constant change until death. Each stimulus, each memory, according to Hayek, evokes its “retinue”, to know, a host of sensory traces that one day accompanied that stimulus or other similar ones (similarity, according to James Mill, is a special circumstance of cooccurrence) and that contribute to the map or network to which the stimulus belongs. When that stimuli and other similar ones reappear in the sensory environment, triggered by associative relationships of the original network, with which triggers the entire stimuli of perception, bringing about in unity the whole perception. With which, furthermore, the network opens to new accompanying stimuli that will amplify or bring “up to date”. Definitely, according to Hayek, to perceive is to classify the world in groups of relations among stimuli previously formed in the history of the organism or of its species. And the nervous system, or its part that is dedicated to perception, from sensory organs to the associative cortex, is essentially a classifying apparatus of relations among stimuli. Perception of an object is defined by the relations among the sensory components of the object. By itself, those components have no mental quality, but together they do. With it, theoretically, a problem that has perplexed psychologists since immemorial times is resolved: the problem of constant perception. How is it that the object continues to be the same in spite of its change of color, of its dimensions and of the space it occupies in the retina? How is it that the melody is the same even though the key, the scale or the instrument that emits it changes? The explanation is found, naturally, in the relation and order of the components. During the years that passed between the time this book’s draft was written and its publication in 1952, there appeared in Europe two important intellectual currents that Hayek used extensively to support and extend his psychological theory. The first was the Psychology of Form or Gestalt (Gestalt psychologie, Koffka, 1935); the second, Biology of the Systems (von Bertalanffy, 1942). The Gestalt psychologist reasoned that the object of perception was the figure, form or structure. They based their concepts, above all, in the field of vision, where an object and its perception are not formed simply by the apposition of elemental luminous impressions of the object on the retina, but by the configuration of those impressions, to know, as result of the order and relation among themselves. The concept of Gestalt, consequently, goes beyond the heralded saying, “the whole is more than the sum of its parts”, which is undoubtedly true. Better to say, the whole is defined by order and the relationships among the parts. Hayek goes even farther. In the first place, he rids Gestalt of the nativism attributed by the founders, who postulated that “forms” have innate representation in the central nervous system, and this representation would manifest itself in the form of hypothetical “electrical fields”. Hayek rejects such concepts, that have no empirical foundation, but without refuting principal elements of Gestalt, and above all maintaining and emphasizing, among them, the relational or associative character of perception. At all levels, from the most elemental up to the most abstract, perception consists of a sensory order that has been formed in the nervous system by classifying acts of the surrounding, that is during the course of history of the species or of the individual. Gifted with the attributes, the relational and the evolutional, Gestalt becomes to Hayek the theoretical foundation of his conception of the sensory order and perception. It is important to add that, though the Gestalt psychologies built their theory almost exclusively in the visual environment, Hayek extended it and applied in all sensory environments. It remains to clarify the neurological base of these theoretical connections, of those relations among sensations that form the networks or “maps” of perception—and now that of the memory—that Hayek postulates. The second intellectual movement that decisively influenced Hayek is the socalled Biology of Systems. This current of thought had its origins in the work of the great philosophers and biologists of the end of the XIX and beginning of the XX centuries (e.g.; Bernard, Cannon, Uexküll). Among them, the one that most influenced Hayek was von Bertalanffy (1942). The fundamental concept of his theory is his theory of organization. The structural and functional properties of a biological system derive from the relations among its components and not from the individual properties of its components. In other words, the meaning of the structure and functions of a system reside exclusively in the organization of its parts and are inherent to it. The conceptual affinity between the systems theory and Hayek’s psychological theory is immediately understood. For him, all sensory order, all perception, are based in the relations among elements, more or less complex, and in their organization in the form of cognitive networks. What is important are the elements and, above all, the relations among themselves. To explain the formation of the contacts in his networks of perception and memory, Hayek uses an old concept of Ramon Cajal that was one of the first, if not the first, in proposing: the synaptic modulation by experience. In his Remembrances of My Life (1923, p. 288) he tells us, possibly paraphrasing him, what he told the participants to an international meeting in Rome with respect to the formation of habits and motor memories: “the functional perfection brought on by exercise (physical education, operations of speaking, writing, playing the piano, mastery in fencing, etc.) […it is due to] the creation of new cellular appendices […] susceptible of improving the adjustment and reach of the contacts, and even of organizing absolutely new relations between neurons primitively unconnected.“ All this Cajal said before Sherrington would invent the word “synapses” to describe those “contacts” between neurons. The fundamental idea is that the formation and consolidation of memory are due to the connection of synapses. Preceding Hebb (1949)—in the fact that this concept would be already mentioned in original version of The Sensory Order—Hayek proposes the beginning of the temporal coincidence of sensory impulses, and in the formation of memory, in order to facilitate the synapses between the neurons that received simultaneous impulses. This concept is completely backed today by data gathered by neurophysiological experiments on animals (summarized by Fuster, 1999). With relatively recent neurophysiological data, about which we cannot expand here, the basic fundamental physiological of association in memory, and subsequently, of the formation and recall of memories has been substantiated. Curiously, it was another Spaniard, Juan Luis Vives (1538), who already in the XVI century had enunciated the principle of simultaneity in the association of the perceptive mind, when he said: “Quae simul sunt a phantasia comprehensa si alterutrum occurrat, solet secum alterum representare” (Of two things simultaneously learned, if one happens it usually evokes the other.) Modern neuroscience gives that saying as its cerebral support. Just as it is done to support Hebb’s and Hayek’s principles of synaptic plasticity. Hayek, in his book, postulates that somewhere in the nervous system, probably in the cerebral cortex according to him, exists a structure and functional isomorphic organization with the organization of its sensory maps and networks. The isomorphism that he proposes is a topological isomorphism. With it he means to say that two hypothetical networks, one mental or perceptive and the other that represents in the cortex, coincide topologically, in such a way that order and relations between elements (nodes) in one are identical to order and relations between the other; I say order and relations, not physical distances between elements—which in a network are sensations and in the other are assemblies of neurons. Hayek makes us imagine two networks of knotted elastic networks, where the knots and the connecting pieces between the knots in one correspond to the knots and connecting pieces of the other. The two networks are topologically isomorphic, thus stretching and twisting any which way one of them, this one retains its topology and its isomorphism with the other. In the same manner, the sensory order would correspond to isomorphic order in the organization of the cortex. The organization of the cortex that Hayek insinuates in this book, like the role played by synaptic plasticity in learning and memory, would later find its neurobiological base in the cortical connectivity that was discovered much later after the book’s publication. It is truly astonishing that its author, in the middle of the ignorance that existed in the first half of the XX century about the anatomical and physiological organization of the cortex, would instinctively coincide with the evidence of the second half of the century. In cognitive neuroscience, as in other fields of human knowledge, the genius of Hayek is in having anticipated with perspicacity what would be verified many years later after it was stated at the theoretical level. During the three decades that passed during 1960 and 1990, new methods were designed to trace nerve connections in the primate’s cerebrum, which is in many ways homolog to the human. In several laboratories around the world, it was discovered with these methods a wealth of connections, unsuspected previously, among the different cortical areas. Each assembly of neurons, in any part of the cortex, seemed to be connected directly or indirectly with whichever other. Furthermore, the connectivity was reciprocal; an area that sent connections to the others, receive them in return, the major part of the connections were short, lacing connections or contiguous areas. Many of the connections, never the less, were long, lacing different areas among themselves, such as the frontal lobe areas, with the occipital, or the temporal ones. Little by little, never the less, in that huge mass of nerve fibers, a certain order was discovered. In first place was seen, that certain areas, to know, the sensory and primary motor areas, those we previously called the seat of the “filetic memory”, are the origins of nerve fibers that cross from area to area toward the more elevated zones of association or integration of the temporal, parietal and frontal lobes. It was also seen than each succession of areas in such discontinuous trajectories form a connective road and an information processing way that goes from an area primary sensorial or of determined motor modality (vision, tact, etc.) towards the cortex of association, supposedly processing and moving higher toward the superior information or motor areas of each modality. It was seen that at each step in the trajectory, the neurons from one area did not only transmit to fibers backwards to preceding area; but, more over, it transmitted collaterally to other sensory roads, as well as, other neurons at superior areas. Definitely, it appears to be that from each primary cortical zone, whether it be sensory or motor, departs an inverted conical weave of connective and neural processing that widens and distributes as it progresses, interconnecting itself with areas of association each time higher and more poli-modal. There is more, that progression toward the high cortical areas continues not only with gradient connections, but gradient in evolution and development, that is to say, filogenetic and ontogenetic. The lowest areas (“filetic memory”) are the ones that develop before, not only during the course of evolution; but, as well as, during the course of perinatal development. The higher areas, those of the superior associative cortex, are the ones that develop more and much later, in the evolution, as well as, during the development of the individual. The frontal cortex, for example, does not reach its maximum development up until the human cerebrum, and itself, until the third decade of life. It is along the length of these three gradients—connective, filogenetic and ontogenetic—how, from the beginning of the primary sensory and motor cortex, the networks of perception and memory are formed from the bottom up. Experiences that happen at the same time strengthen the synaptic contacts between the assemblies of neurons that receive what those impulses generate. New experiences, by association, reactivate old networks, expanding and reconfiguring the latter. The memory network each in its turn more complex and more abstract grow superimposing one above the other toward levels each time of higher cortical representations in the areas of superior associativity. All this constitutes a dynamic network formation process that retains memory in its connective tangle and at the same time serve to perceive, that is to say, to interpret and classify, the new experiences in the context of previous established memories. At the root of this dynamic network formation process, by which what is sensory— like that, which is motor—becomes mental, is the easiness of connectivity between neurons. It is because of this selective ease of synapses in this huge connective structure of the cortex how the memories of the individual are formed on the filetic memory base—sensory cortex and primary motor—that is common to all individuals of the species. The idiosyncrasy and specificity of the memory of the individual resides in the ability of each individual to combine the ten thousand million or so neurons that reside in the human cortex. As Hayek premised, the process of the formation of cognitive networks is a self-organizing connective process of the cortex under the influence of experiences. Under the use that experience imposes, the synapses between neurons simultaneous activated are facilitated, by which the network that unites them are formed or strengthen. It is, thus, with use how, the immense connective substrate that is in good part indefinite nerve roads, make their own roads that constitute the network and defines it. Things happen in somewhat the same way as the poet used to say: “Traveler there is no road, it is made as you walk” (Antonio Machado, Campos de Castilla). That dynamic formation of cognitive networks, whose consolidation does not seem to stop during dreams, leads to the organization of the sensory order in the cortex similar to the one espoused by Hayek with much less knowledge, compare to what we know today, about the marvelous structure of the human brain. From our neuroscientific perspective of the XXI century (Fuster, 2003), the cognitive networks that he postulated, serve perception as well as memory, appear organized hierarchically, intertwine between themselves and sharing neuronal assemblies (the “knots” of the net) in very distinct levels of the hierarchy. The lowest networks of the hierarchy, those that represent more concrete memories, sensory as well as motor, reside in primary cortical areas and in foreign areas, the sensation entry points in the cortex and the exit points of the motor cortex to the kinetic apparatus. Above this network, in the associative sensory cortex, the more complex associative memories are found “declarative”, episodic and semantic; and associative motor cortex; one finds the memory that executes programs and sequential actions. Lastly, in the superior levels of the associative cortex of the parietal, temporal, and frontal (prefrontal cortex) lobes, reside the more abstract networks, representative of general concepts and action plans. All the levels of networks keep connected among themselves and the common nodes, by which and assembly of neurons, practically in any part of the cortex, can be part of many networks, and consequently of many memories. Thanks to modern neuroscientific methods, today we know that the function of the networks or neuronal “maps” of cortical representation that Hayek proposed to explain the sensory order in the human mind transcends perception and memory. Neuro-imaging and electro-physiology in man and primate permits us to affirm that to those two functions it is necessary to add attention, intelligence and language. It is to say, that the five cognitive functions are the result of selective and orderly activation, in time and cerebral space, of the cognitive networks that represent our internal and external worlds. Taking into account the little that was known in his time about the cerebral cortex, Hayek was not able to know the precise order that reigns in the structure and function of those networks, but he guessed with masterful precision the principles of that order or, to say it his way, “the explanation of the beginning”.


Hayek, Popper, and the Causal Theory of the Mind

Here is the introduction to Ed Feser’s paper from Hayek in Mind.

In late 1952, F. A. Hayek sent his friend Karl Popper a copy of his recently published book The Sensory Order: An Inquiry into the Foundations of Theoretical Psychology. In a letter dated December 2, 1952, Popper acknowledged receipt of the book and responded as follows to what he had read in it:

I am not sure whether one could describe your theory as a causal theory of the sensory order. I think, indeed, that one can. But then, it would be also the sketch of a causal theory of the mind. But I think I can show that a causal theory of the mind cannot be true (although I cannot show this of the sensory order; more precisely, I think I can show the impossibility of a causal theory of the human language (although I cannot show the impossibility of a causal theory of perception). I am writing a paper on the impossibility of a causal theory of the human language, and its bearing upon the body-mind problem, which must be finished in ten days. I shall send you a copy as soon as it is & typed.

In a later letter dated January 19, 1953, Popper added, As to my comments on your book, they are, as far as criticism is concerned, implicit in my paper. I think you have made a splendid effort towards a theory of the sub-linguistic (¼ sub-human ((¼descriptive)) language) level of mind; but I believe that no physiological approach (although most important) can be sufficient to explain the descriptive and argumentative functions of language. Or in other words, there can be no causal or physiological theory of reason. The paper Popper was referring to is his short article ‘‘Language and the body-mind problem.’’ Hayek began a draft of a paper entitled ‘‘Within systems and about systems: A statement of some problems of a theory of communication,’’ which, as Jack Birner has suggested, appears to have been intended at least in part as a response to Popper’s criticisms. But it was never completed, and Hayek never addressed Popper’s arguments in any of his published work. The Sensory Order has, however unjustly, largely been forgotten outside the circles of Hayek specialists. Popper’s brief paper is perhaps even less well known. Neither Popper’s letters to Hayek nor Hayek’s unfinished draft have yet been published. So, this episode might seem rather insignificant in the history of thought and indeed of little significance even to our understanding of either Hayek’s thought or Popper’s. But, as I hope to show in what follows, nothing could be further from the truth. With respect both to its general themes and to some of the specific philosophical moves made by each side, the brief, private dispute between Hayek and Popper foreshadowed a more prominent debate within twentieth-century analytic philosophy that began in the 1970s and continues to this day. Moreover, both the dispute between Hayek and Popper and the later debate reflect a deep tension that has lain at the heart of Western thought since the time of the scientific revolution. On the one hand, there is the ‘‘mechanical world picture’’5 according to which all natural phenomena can be explained entirely in terms of the mathematically describable behavior of matter in motion. On the other hand, there are rational human thought processes, including the philosophical and scientific theorizing that led to the mechanical world picture itself. It is far from obvious that the latter can be fitted comfortably into the former – that human rationality can be explained in terms of purely material processes – and from the time of Descartes until relatively recently, the dominant view was that it could not be. Hayek and Popper were writing at a time when this view began to give way to a new materialist orthodoxy. Hayek, though arguably more sensitive to the tension in question than most contemporary materialists, nevertheless thought it could be resolved in a way favorable to a broadly materialist or ‘‘naturalistic’’ understanding of the mind. Popper disagreed and believed the older, dualistic conception of the mind to be essentially correct, and as we will see, his reasons for doing so have in more recent years been regarded even by some non-dualist philosophers as posing a serious difficulty for materialism. In the next section, I will set the stage for the discussion of Hayek and Popper with a brief account of the nature and origins of the mind-body problem (or ‘‘body-mind problem,’’ as Popper preferred to call it). We will see that there are really at least three mind-body problems, and that while Hayek and most contemporary philosophers focus on the first of these, Popper was more concerned with the other two and believed that they pose a more serious difficulty for materialism than the former does. The third section will explain what a ‘‘causal theory of the mind’’ is and the respects in which Hayek’s account can be regarded as a causal theory. The fourth section will examine Popper’s main criticism of causal theories, which will be elucidated by comparison with the views of contemporary philosopher Hilary Putnam, who (apparently independently) developed a line of argument that parallels and extends the one presented by Popper. Finally, in the fifth section, I will consider the possible response to Popper suggested both by Hayek’s unpublished draft and by things Hayek had to say in some of his published work, relating it to the responses contemporary philosophers have given to arguments like those presented by Popper and Putnam. I will argue that none of these replies succeeds and that the Popperian critique remains a powerful and as yet unanswered challenge not only to dogmatic materialism but even to the more modest and critical form of materialism or naturalism defended by Hayek.