In the late 2000s and early 2010s, I put a lot of effort into studying David Hume’s work and building a phenomenalist foundation for linguistics with the help of his work. I shelved the project after a while (not because it wasn’t going well but because I got sidetracked). And then in the early 2020s, a decade later, I happened to go back to Friedrich Hayek’s book The Sensory Order (1952), which I had read soon after graduating high school but without getting much out of it. Suddenly, though, in a flash of insight, it all made sense: Hayek’s work in that book and that work’s relationship with my work.

With Hayek’s help, then, I wrote several essays on my late-2000s, early-2010s project, transforming that project from Humean-phenomenalist linguistics to Humean-Hayekian-phenomenalist linguistics.

There’s something else that I should also mention that influenced me between my late-2000s, early-2010s work on Humean-phenomenalist linguistics and my recent work on Humean-Hayekian-phenomenalist linguistics: Around when I went back to The Sensory Order, I spent a lot of time and energy on logic. Besides doing my own thinking, I studied with great interest John Stuart Mill’s 1,000+ page textbook A System of Logic (1843) and Morris Cohen’s more concise and eloquently written textbook An Introduction to Logic and Scientific Method (1934).

To summarize:

1. There was my late-2000s, early-2010s work on adapting Humean phenomenalism to linguistics.
2. There was my newfound appreciation, as of the early 2020s, for Hayek’s effort to reconcile phenomenalism, which is a well-respected, traditional doctrine in philosophy, with 20th-century science.
3. And there was my newfound understanding, also as of the early 2020s, of logic.

With all of that, I found myself better oriented than ever in all of the ways that mattered for building the phenomenalist foundation for linguistics that I first envisioned as a teenager in the late 2000s. That long-standing ambition of mine—shelved but never forgotten, unshelved after a decade—had matured into something even more promising: Humean-Hayekian-phenomenalist logico-linguistic system building.

In Christian cosmogony, it was God who (1) made something out of nothing and then (2) gave that something the order that it has. In Dialogues Concerning Natural Religion (1779), David Hume argued for “a new hypothesis of cosmogony,” which was a challenge to the latter doctrine: that without God, the order in the world of matter has no good explanation. In essence, he argued that the order in the world of matter can be accounted for without hypothesizing supernatural intervention, for that order is the natural result of something that everybody knows: that some configurations of matter are more stable than others. If some matter in an unstable form by chance falls into another unstable form, then by definition (i.e., by definition of the term “unstable”) it’s unlikely for the matter to stay in that form for a long time. It’s when matter instead by chance falls into a stable form that it’s likely to stay like that. Chaos falls into chaos until it settles into order.

Interestingly: In The Selfish Gene (1976), Richard Dawkins used that Humean argument in order to contextualize biological evolution. Hume explained how chaos naturally settles into order (which is an explanation of any kind of evolution, whether biological or not), and to that explanation Dawkins added the idea of a replicator (which is how biological evolution works in that context).

Why are there so many rocks? Because rocks are especially stable. If some matter by chance falls into the form of a rock, then it’s likely to stay like that. And why are there so many birds? Not because birds are especially stable on the level of the individual, like rocks, but because birds are especially stable on the level of the group. They’re especially good at replicating themselves, and thus keeping the group in existence, before themselves falling out of existence.

That Humean argument, however, falls to thoroughgoing subjectivism. The difference between chaos and order isn’t inherent to the world of matter. The difference instead comes out of something subjective: categorization.

Rocks are stable because rocks are rocks whether they’re big or small, rough or smooth, etc. But why categorize like that? A big “rock” can fall and break into small “rocks,” and a rough “rock” can be made into a smooth “rock” after enough time in a river. Our categorization scheme is such that through those transformations they’re all still “rocks.” How stable! Theoretically speaking, though, it’s possible to use any categorization scheme that you want. Anything can be thought of as staying the same through any transformation, and anything can be thought of as not staying the same through any transformation. It’s possible to imagine a categorization scheme that puts even rocks into chaotic flux.

1. The order of English, as an internal categorizational system, is mapped onto both the phonological order of English and the orthographical order. That is: The internal categorizational system is externalized into both its spoken and written counterparts.
2. Analogously, the order of the physical world is mapped onto the auditory sensory order, the visual sensory order, and the tactile sensory order, along with the orders of the rest of the sensory modalities. In fact, epistemologically speaking we should, and do, actually go in the opposite direction: We compare the sensory orders of all of the different sensory modalities, looking for where there’s isomorphism.
3. The thymological order, generalized into a (human-)universal description and explanation of the (human) mind; here we find another order, and we can theorize that order (i.e., the human-universal-generalized thymological order) to be in part isomorphic with the human-universal-generalized physical order of “the” brain and nervous system. That is, we can theorize that the mental patterns inherent to being human can be in part mapped onto certain physical patterns.
4. George Boole in The Laws of Thought (1854) showed that the order of the symbolic system of arithmetic and algebra, including the order of its rote manipulation, is isomorphic not only to arithmetic and algebra but also to part of logic.

In The Sensory Order (1952), it was as if Hayek was saying: “You want a (physical) science of human behavior, which would necessarily go along with a (physical) science of the human brain and nervous system? That is, you want a physical science to replace the traditional way of thinking about human action and the human mind? A physical science to replace economics, linguistics, and the rest of the praxeological and thymological sciences? Well, here you go. Good luck.” In other words: Hayek, being famously diplomatic, didn’t just turn his back on the mainstream and go his own way. Instead, he worked together with the mainstream: He took the mainstream’s approach as seriously as possible, and in fact did (some of) their work for them—he steelmanned the mainstream in the most heroic way possible—but in doing so he showed, indirectly, the fool’s errand that it really is.

Physics builds the physical order out of the sensory order. Psychology, in turn, conceived of as a physical science, must then go in the opposite direction. It must build the sensory order out of the physical order. That is: We build a model of (1) what’s physically happening out in the world, along with a model of (2) what’s physically happening in the brain and nervous system, as a reflection of (3) what’s physically happening out in the world; and with all of that, we go far from the sensory order only to just circle right back.

Economics, along with the rest of the social sciences, as traditionally done (e.g., in Smith, in Mill) take for granted the direct sensory order. Those sciences, though, if made into physical sciences, in order to conform to the zeitgeist of modernity, would no longer be able to take that for granted. They’d need to instead be founded on the indirect sensory order. Thus: In taking the mainstream’s own project seriously, and putting it on a better footing than ever before, Hayek showed, indirectly, the futility of the project—well, at least in the short term.

To be fair, though: Hayek’s work on the subject wasn’t just a reductio ad absurdum. It wasn’t just him taking the mainstream premises to their logical conclusions as a way of showing, diplomatically and indirectly, the impracticalities of those premises in the social sciences. Distractingly, perhaps, Hayek was also genuinely interested in the physiology of consciousness for its own sake, including the pre-conscious factors in the development of conscious experience of one kind vs. another, those pre-conscious factors being both organism- and species-level. However, that interest wouldn’t have carried him so far back into the subject, after he had shelved it for 30+ years, if not for the profound significance to the questions of (1) how to do natural science properly, (2) how to do social science properly, and (3) how to keep natural science in its proper place.

In building a model of the grammar of a natural language, we often find that (1) two different linguistic forms have the same logical substance and (2) the same linguistic form has two different logical substances. For example: (1) The two words “have” and “has,” as in “I have a cold” and “he has the flu,” differ only in linguistic form; their logical substance is the same. (2) And the one word “have,” as in “I have a cold” and “he could have gotten the flu” differ not in linguistic form but in logical substance. The former meaning of “have” is obvious. If you “have” a cold, then you’re in that state. The latter meaning, by contrast, isn’t so obvious. It’s that of the past tense. Compare “could” and “could have,” “would” and “would have.”

Imagine building a system of logical notation that has a way of symbolically representing the past tense, the present tense, and the future tense, along with many of the other logical distinctions underlying the grammatical system of natural language. In effect, you’d be building a differently aligned language, in its connections between the surface form of its symbols and the deep substance of its meaning. You’d be realigning, reclassifying; you’d be building a different order.

What we do in physics is analogous. In doing physics, or (in other words) in building a physics model of sensation, we often find that (1) two different sensory forms are caused by the same physical substance and (2) two different physical substances cause the same sensory form. Physics, then, in an analogous way to logic, is an artificial realignment for a philosophical or scientific purpose. Physics replaces the “natural language of sensation” (metaphorically speaking) with an “artificial language of sensation.” In that way: Linguistics is to logic as the introspective psychology of sensation is to physics. Just as linguistics and logic study two separate but interconnected orders, one being more natural than the other, the introspective psychology of sensation studies the “sensory order,” as Hayek calls it, and physics studies the “physical order.”

The natural science of the psychology of sensation, then, studies the “neural order,” which is the interconnection between the sensory order and the physical order. According to Hayek, something in (the physical structure of) the brain, along with the rest of the nervous system, must be isomorphic to (the mental structure of) of the mind. What that “something” is, which can be theorized right from the start of the inquiry as necessarily existing, is left as an open question for me (and not a very highly prioritized one)—though Hayek does make some interesting guesses—for the philosophical significance of Hayek’s starting point in theoretical psychology to the question of the epistemology of the sciences of human action and the human mind doesn’t depend on the answer to that question, i.e. the question of what that “something” is.

The significance is simply that building a properly founded natural science of human behavior and the human nervous system, without sneaking in through the back door anything that’s just directly taken from introspective psychology, would be extraordinarily roundabout (not to mention of dubious utility to economics, linguistics, and the other praxeological and thymological sciences).

That is: We’d have to go from the sensory order, as we experience it naturally, to the physical order, and then we’d have to turn back, going from the physical order, through the neural order, all the way back to the sensory order, but no longer as we experience it naturally: We’d have to build a sufficiently accurate and detailed (physical) model of the brain, along with the rest of the nervous system, that’s in some way isomorphic to a correspondingly sufficiently accurate and detailed (mental) model of the mind. And then we’d just be right back where we started!

It’s the spirit of the Scottish Enlightenment that’s closest to the spirit of my work. Francis Hutcheson (1694-1746) was one of the founding fathers of the Scottish Enlightenment, and soon after Hutcheson came several giants, David Hume (1711-1776) the greatest among them.

In the 19th century, though, Alexander Bain (1818-1903) was one of the most important of the Scots still working as part of the tradition of the Scottish Enlightenment, and (according to The Stanford Encyclopedia of Philosophy here) Bain stood on the cusp: He argued for the replacement of “the philosophy of mind” with “empirical psychology,” which in doing so he helped bring about—though of course the zeitgeist of the 19th century surely made that transition inevitable. In short: The kind of thinking that Hutcheson, Hume, and others did was no longer considered to shed light on metaphysics (i.e., on questions about the ultimate fundamentals of reality). It was demoted to being about the mind and the mind only. It became nothing more than the systematic introspection into the system of the mind, with the mind taken in that new paradigm as a thing apart from reality.

The killing blow, then, to the weakened tradition of the Scottish Enlightenment, was the tabooing of introspection. The “philosophy of mind” (the term “philosophy” at that time being equivalent to the term “science” nowadays) became “empirical psychology,” and then in turn what was admitted as “empirical” eventually shifted: The mind was no longer admitted as a proper object of empirical observation. In psychology, from then on, only models of the brain (along with anything else physical, e.g. the eye, the ear) were taken as properly scientific.

In summary: The “philosophy of mind” in the 18th century became a kind of “empirical psychology” founded on introspection in the early 19th century, which in turn became a different kind of “empirical psychology” by the late 19th century. The analysis of the mental mechanisms of human action and the human mind was pushed aside, and the analysis of the physical mechanisms thereof took over.

With all of that said, however: I’d like to argue that, actually, the tradition of the Scottish Enlightenment didn’t just degenerate first into introspective psychology (with Bain) and then into non-introspective psychology (post-Bain); it actually split off at the root, growing not only into psychology, on one hand, but also logic, on the other hand. Hume introspected in order to understand (the fundamentals of) the system of the mind in its understanding of (the fundamentals of) the system of reality. Post-Bain, the new field of psychology specialized in the former part of that, viz. in the goal of understanding the mind in a fundamental and systematic way, and the new field of logic specialized in the latter part of that, viz. in the reality-related considerations. And mirroring the further degeneration into non-introspective psychology, logic too degenerated: It lost its substance as it transformed into formal logic. John Stuart Mill’s treatise A System of Logic (1843), which Mill thought of as a contribution to the “science of science itself,” soon went out of fashion—it was almost entirely prose. Boole in The Laws of Thought (1854) adapted algebraic notation to logic, and from then on it was formal (or mathematical) logic that inspired the intellectual world—a project that (to no fault of Boole’s) became increasingly unmoored from the Scottish tradition (along with the broader British tradition, e.g. in Locke, in Berkeley) of checking whether there’s actual substance underneath the pretty surface form of eloquent words and other symbols.

And finally, in the 21st century: Introspection is taboo in science, the physical is taken much more seriously than the mental in psychology and elsewhere (in keeping with introspection as taboo in science), a substance-unchecked mathematics has all but swallowed up logic, and there are few thinkers left in philosophy of science.