Against Panpsychism

A critique of panpsychism from a physics perspective.

Background

Panpsychism is having a moment. After decades of being treated as a philosophical curiosity (or a relic of pre-scientific animism or something even less fashionable), the view that consciousness is somehow a fundamental feature of reality has been making its way into respectable philosophy departments, popular science books, podcasts, and even the occasional physics-adjacent academic conference.

Galen Strawson has been arguing for it forcefully since the early 2000s. Philip Goff wrote Galileo’s Error (trade book aimed at general readers) making the case for it in 2019. Annaka Harris has been popularizing the view via her writing and a podcast. David Chalmers, who basically launched the modern debate over consciousness with his 1995 “hard problem” paper, has written sympathetically about Russellian monism (a close cousin of panpsychism) for years. There is now a lively academic literature around the view, complete with its own conferences, journals, and, of course, internecine disputes.

I’ve previously argued that the hard problem of consciousness is, on close inspection, a confusion masquerading as a discovery. Panpsychism seems to be the most fashionable response to the hard problem, and a number of readers have pushed back on my earlier piece by appealing to it. So this is my attempt to push back again the pushback by taking a close look at why panpsychism fails - not just as a philosophical proposal, but as the kind of claim it actually is, which is a claim about the basic nature of the universe.

The thesis I want to defend here: panpsychism is not primarily a philosophical position, and treating it as one is part of why it gets undeserved respect. It is a hypothesis about what fundamental physics describes, and once we evaluate it on those terms, it falls flat. The motivating intuition that drives it (the worry that consciousness “can’t emerge from unconscious matter”) turns out to undermine panpsychism just as effectively as it (allegedly) undermines physicalism. And besides that internal problem, the weight of modern physics, neuroscience, and biology points the other way.

1. The Most Respectable Formulations

Let’s start by attempting to give the view a fair shake before critiquing it.

Modern panpsychism is not the cartoon version where rocks have feelings and electrons fall in love, although I think that this would make for a great webcomic. The serious contemporary versions are subtle, and they trace back (more or less?) to Bertrand Russell’s The Analysis of Matter (1927). (There may have been earlier precursors, but Russell’s framing seems to have significantly influenced modern approaches.)

Russell’s observation was this: physics describes the world entirely in terms of structure and dynamics - what things do, how they relate, what mathematical patterns they follow, etc. Physics tells us that an electron has a certain charge, mass, spin, etc. and that it interacts with other things in certain quantitatively specifiable ways. But (so the argument goes) physics never tells you what an electron “is”, intrinsically. It tells you about the relations and behaviors. The intrinsic nature - the “what it is” of fundamental physical stuff - is left as a black box. Russell suggested that consciousness might be the only intrinsic nature we ever have direct acquaintance with (since it’s our own experience), and that other things (electrons, fields, what have you) might have their own intrinsic natures of which our consciousness is a “particularly elaborate” species.

(My genealogy of the ideas here is not meant to be exact. The SEP article on panpsychism is quite good and covers this.)

Starting from that approach, we now have a fair number of modern positions that seem to tie back to Russell’s argument.

Let’s go over a few of these - note that some of these positions are close to panpyschism but not quite panpyschism:

Constitutive panpsychism (Goff is probably its best-known contemporary defender) holds that consciousness is a fundamental property of basic physical entities - quarks, electrons, fields - whatever turns out to be ontologically basic, and that the consciousness we have is “constituted” by combinations of those micro-experiences.

Panprotopsychism is a more cautious cousin: rather than saying basic stuff has consciousness, it says basic stuff has “protoconscious” properties that, when suitably combined, give rise to consciousness. The idea is to retain the explanatory power of “no consciousness from non-consciousness” without committing to electron feelings. (Feel free to insert your own favorite disappointed electron meme gif here.)

Russellian monism is the broader umbrella term for “physics describes structure, intrinsic nature is something else, that something else is (or is closely related to) consciousness.” This approach can be either constitutive or panprotopsychist in flavor.

Cosmopsychism flips the bottom-up move: the universe as a whole is the fundamental conscious entity, and individual minds are derivative “slices or aspects” of cosmic consciousness. (You can hear some Vedantic echoes here, which is fine - philosophy has often recycled.)

This is not an exhaustive list of formulations, they are the ones I found most interesting and respectable. For the most part, they aren’t claiming that your toaster is contemplating the meaning of life. They’re making a structural claim about the relationship between physics and phenomenology.

2. The Motivations (and the Strongest Case)

In my view, two motivating intuitions seem to be doing most of the work for panpsychism, and they’re worth taking seriously even if (as I’ll argue) neither survives scrutiny.

The “no emergence” intuition. This is the engine of the whole project. The idea is that you can’t get consciousness from a substrate that has no consciousness in it, any more than you can get extension from non-extended points or wetness from non-wet atoms. Strawson, for example, is quite insistent on this. If your starting ingredients are entirely dead matter, with no glimmer of experience, then no rearrangement of those ingredients will produce experience. Therefore the ingredients themselves must already have “some” experiential character.

So, I’ll say this for this intuition: it has rhetorical force. It feels right when you read it. (It’s one of the most common arguments for panpsychism I come across on X, for example.) But, as I’ll get to below, it has the unfortunate property of being self-defeating.

The Russellian “intrinsic nature” gap. This is the more sophisticated motivation. The argument goes something like this: physics gives us only the relational/structural skeleton of the world. There must be intrinsic natures grounding those relations, and we have one example of intrinsic nature on offer (our own conscious experience). Parsimony then suggests we extend that example to the rest of nature rather than positing some entirely new species of intrinsic nature for the non-mental world.

(As someone who tends to think positively of structural realism, the “physics describes structure” argument is one I can appreciate, even if I disagree with the rest of the argument.)

Now let me try and state the panpsychist case at full strength, because I think it’s sometimes dismissed too quickly. This rehashes some of the material I already covered, but please bear with me - I am trying my best to steelman this.

The strongest version (in my opinion) goes something like this. Modern physics gives us, on the structuralist reading, a mathematically beautiful description of “what fundamental entities do”. It tells us how electrons move, how fields couple, how spacetime curves. It does not tell us “what fundamental entities are”, in the sense of what their intrinsic, non-relational properties are - because, by construction, physical theory traffics only in dispositional and structural features. Thus, there is an entire ontological category (the “categorical” or “intrinsic") about which physics is, by its very methodology, silent. If we ask what fills that category, we have exactly one positive datum: our own consciousness, which we have direct acquaintance with and which does not present itself as a structural relation but as something with intrinsic phenomenal character. The parsimony argument (which panpsychists note, physicalists like me love to invoke) then suggests that we should fill the categorical-nature gap with the same sort of stuff we already have on offer (proto-experience), rather than positing some entirely novel kind of intrinsic nature about which nothing whatever can be said. On this telling, panpsychism isn’t a mystical addition to physics. It’s a “parsimonious completion” of it.

That’s a real argument. And it deserves engagement, not dismissal. The reason it ultimately fails (which I’ll develop in sections 3-7) is not that it’s silly, but that the proposed completion doesn’t actually do the explanatory work it claims, and runs afoul of the physicalist-friendly considerations the panpsychist is trying to honor.

3. The Self-Defeating Logic of Anti-Emergence

Here’s where I think the contemporary debate has been strangely lopsided.

The core panpsychist move is - “consciousness can’t emerge from non-conscious stuff.” Okay. Suppose we grant that, just for the sake of argument. Now let’s ask: how is sophisticated, unified, semantically rich human consciousness supposed to arise from the aggregation of trillions of (allegedly) micro-conscious quarks, electrons, and field excitations?

This is the famous combination problem, and it has been the chief internal headache of panpsychism since William James first raised it in The Principles of Psychology (1890). Chalmers has called it “the hard problem of combination” and, on this point, I think he’s exactly right.

But let’s examine this problem a little closer than the standard treatments do, because the strongest panpsychist response seems to miss what’s really going on.

The strongest panpsychist response runs as follows: yes, the combination problem is hard, but it’s hard in a “categorically less mysterious way” than the matter-to-mind problem. Going from micro-experience to macro-experience is at least staying within the same ontological category - we’re combining experiential stuff with experiential stuff, like making a wave from many smaller waves. Going from non-experience to experience, by contrast, is alleged to be a discontinuous leap into an entirely new ontological domain. So the panpsychist can grant that combination is hard while still claiming it’s a fundamentally less daunting problem than physicalist emergence.

This response is wrong, and it’s wrong in a specific, instructive way.

The “category preservation” reply works only if we ignore what the macro-experience actually is. Human consciousness is “unified”. It’s a single perspective, a single point of view, one set of experiences that is “had” by one subject. The transition the panpsychist needs to explain is therefore not just “combining experiences” but combining “many discrete tiny perspectives into one unified perspective”. And that transition is exactly the kind of boundary-crossing the panpsychist objected to in the first place - it’s a transition from a state-of-affairs in which there are many subjects (many discrete proto-experiences) to a state in which there is one unified subject. The fact that both states involve “experiential” stuff doesn’t make the transition trivial by any means. It might actually make it harder, because now we have to explain how “experiential facts” (which panpsychists suggest are fundamental) can be merged into a single experiential fact without violating their fundamentality.

Think about it this way. The panpsychist’s anti-emergence intuition says: experience cannot arise from a substrate that lacks it. Fine. Now apply the principle: “unified experience” cannot arise from a substrate that lacks unified experience. By the panpsychist’s own logic, you cannot get unification by aggregation. Unified experience, on the same anti-emergence principle, would have to be fundamental.

But then we’re not in panpsychism anymore - we’re in “cosmopsychism” , where the universe as a whole is the unified experience and our individual minds are decompositions of it. And this is where cosmopsychism’s apparent escape from the combination problem turns into a “decombination problem” that is, if anything, even worse. If the cosmic mind is the fundamental unit, how does it split into many private, mutually inaccessible perspectives? What “principle of decomposition” takes one cosmic experience and gives you several billion discrete human experiences, each closed off from the others? Whatever answer you give to that question is going to require exactly the kind of “many-from-one” or “one-from-many” account that motivated the combination problem on the way up.

(The Borg notably solved this problem by fiat. The cosmopsychist does not get to invoke fiat.)

The situation is problematic for panpsychists either way you run it. Run it bottom-up, and we have a combination problem that the very anti-emergence intuition we started from seems to forbid. Run it top-down, and we have a decombination problem that does the same work in reverse. As far as I can tell, no one has solved either, and the proposals I’ve read tend to either slide back into garden-variety emergence (in which case the proto-consciousness is doing no explanatory work) or to introduce new metaphysical primitives “without independent motivation”.

The honest summary: panpsychism trades one alleged emergence miracle for another. If the physicalist owes you an explanation of how subjective experience arises from neural activity, the panpsychist owes us an explanation of how a “single, integrated, narratively-structured” experience arises from the proto-experiences of an astronomical number of micro-entities (or, in the cosmopsychist case, decomposes from a single cosmic experience into many private ones).

4. The Core Theory Constraint, Again

I worked through this argument in my hard problem essay, but it bears repeating, because panpsychists (in my opinion) have not taken it seriously enough.

As Sean Carroll summarized in Consciousness and the Laws of Physics and elsewhere, the laws of physics underlying everyday phenomena (Frank Wilczek’s “Core Theory“ - the Standard Model of particle physics plus the weak-field limit of General Relativity) are completely known within the energy regime relevant to anything that happens inside a human body, a brain, a planet, or for that matter our entire solar system. We’ve probed the relevant energy levels experimentally for decades. Within that domain, there is no room for additional fields, forces, or dynamical degrees of freedom that we haven’t already catalogued.

Now, let’s use this to scrutinize panpsychism. The panpsychist says fundamental constituents of reality have proto-experiential properties.

(Yes, I did use the following type of argument in my hard problem essay.)

This means that we two options:

Option A. These proto-experiential properties actually affect the dynamics of physical systems. As a result, conscious matter “behaves differently” than non-conscious matter would. In which case: this would show up in our physics experiments. We would see deviations from the predictions of the Standard Model. We would be able to design experiments to detect proto-consciousness in fundamental fields. (And if we found it, the people involved would get Nobel Prizes for it.) But, none of that is true. The data say loud and clear that the dynamics of the Core Theory are sufficient to describe the behavior of the matter that brains are made of.

Option B. These proto-experiential properties leave the dynamics of the Core Theory completely intact. Quarks behave exactly as the Standard Model says they behave, with or without their alleged inner light. (To be charitable, this option seems to be what serious Russellian monists actually defend.) But this would be a case of epiphenomenalism and is really not doing any work at all.

Now, the Russellian monist would reply to this charge (that Option B is just epiphenomenalism) along these lines: proto-consciousness isn’t causally inert because the structural properties physics describes “are constituted by” the proto-conscious intrinsic properties. Physics doesn’t see it because physics is constitutively a structural science - it tells you what intrinsic natures “do”, not what they “are”. Proto-consciousness is the categorical basis of physical causation itself. Asking why we don’t see it in physics experiments is like asking why we don’t see the “shape” of a key in the door it opens - the shape isn’t causally redundant; it’s what makes opening-the-lock possible.

This is a intriguing response, and it’s worth taking seriously. Here’s the thing though: it really just relocates the failure without rescuing the position. Here’s why.

Grant the Russellians everything they want about physics describing structure and intrinsic nature being the categorical basis of that structure. Now ask: what work is the “proto-experiential” characterization of intrinsic nature doing, beyond what “categorical basis of physics, content unknown” already does? The answer is: nothing observable! By the Russellians’ own admission, swapping proto-experiential intrinsic natures for any other categorical basis with the same structural role would leave physics, neuroscience, and behavior identical. The proto-experiential identity is sitting on top of the structural facts adding “zero predictive content” - and, mind you, adding zero explanatory content too, because we can’t show that proto-experience does any explanatory work that “neutral categorical basis” wouldn’t do equally well. We can’t even check whether proto-experience is the right answer rather than (say) proto-numericality (numerality?), proto-extension, or proto-anything-else with the same structural footprint.

That’s the actual problem with Option B. It’s not that it’s epiphenomenal in the crude sense of “consciousness floating uselessly above physics.” It’s that the “specifically experiential” characterization of the proposed categorical basis is a free metaphysical ride that, by stipulation, can’t be wrong - and which, by stipulation, makes no contact with anything we can investigate. A view that is compatible with literally any observation tells us, in the end, nothing about the world.

(I anticipate the protest that panpsychism is a metaphysical hypothesis, not a scientific one, and so different standards apply. I disagree, as you’d expect, and section 6 below is where I argue against that notion.)

5. The Evolutionary Tell

Set aside the metaphysical and physical arguments for a moment. Look at consciousness empirically.

What do we actually observe?

Consciousness in nature scales with biological complexity, in ways that track quite precisely the elaboration of certain kinds of nervous systems. Bacteria have no nervous system; nobody seriously thinks they’re conscious. Simple invertebrates with rudimentary nerve nets show responses to stimuli but no integrated processing. Fish, reptiles, and birds have progressively more elaborate nervous systems and progressively more flexible, integrative behavior. Mammals (especially the more “sophisticated” ones) show clear hallmarks of unified perception, emotion, and learning. Among mammals, primates seem to have additional layers of self-modeling. Humans (with our particular cortical architecture) layer on top of all that the abstract thought, language, and narrative selfhood (that has us socialmaxxing and writing essays at each other on the internet trying to argumentmogg each other.)

This “consciousness gradient or spectrum” in the animal kingdom is fairly smooth. The correlation with neural complexity is also strong. The “kinds” of consciousness present at each level look exactly like what you’d expect from an evolved adaptive function - integrative information processing in service of survival, reproduction, action selection, and behavioral flexibility.

Now, panpsychists might retort with something like: “Of course rich, human-style consciousness scales with brain complexity - that’s the combination phenomenon. We never said proto-consciousness shows up phylogenetically; we said proto-consciousness is fundamental and rich consciousness is constituted by combinations of proto-consciousness in specific architectural arrangements. The phylogenetic gradient is consistent with our view.”

Okaaaay. I don’t think the phylogenetic gradient “refutes” panpsychism in the strict logical sense. But here’s what it does do - it makes panpsychism “explanatorily idle”.

The panpsychist concedes that the rich, unified consciousness we actually observe in nature is fully accounted for by structural and architectural features of nervous systems. The phylogenetic gradient maps onto neural complexity; the molecular specificity of anesthesia maps onto specific neural circuits; the lesion data map onto specific brain regions. All the explanatory work in producing the consciousness we actually observe is being done by the wiring. The proto-consciousness is sitting at the bottom of the ontology contributing nothing “observationally distinguishable”.

If a theory adds an entity (proto-consciousness in fundamental fields), and that entity does no observable work in the actual production of the phenomenon you’re trying to explain (rich human consciousness), then the entity is unmotivated. We don’t posit “proto-photosynthetic” properties of fundamental matter to explain why plants do photosynthesis. We don’t posit “proto-digestion” to explain why animals digest food. We explain those phenomena the obvious way - a particular molecular machinery does a particular job in a particular context, and natural selection made it happen over time. The fact that consciousness “feels” different from photosynthesis doesn’t justify a different methodology. Or rather, if it does, the burden is on the panpsychist to show why.

This is because consciousness shows every fingerprint of a biological adaptation:

• It scales with the complexity of integrative neural machinery.

• It is selectively impaired by lesions to specific brain regions (especially thalamus, cortical hubs, and the ascending arousal system).

• It can be turned off by general anesthesia, which acts on specific molecular targets in specific neural circuits.

• It tracks specific patterns of neural activity (the so-called Neural Correlates of Consciousness, identified through decades of work by Crick, Koch, Dehaene, Tononi, and others).

• It develops in individual organisms as the relevant neural circuits mature.

• It can be modulated by drugs, stimulation, fatigue, sleep stages, and disease in highly specific ways.

Every one of these features is exactly what you’d expect if consciousness were a high-level functional property of certain kinds of evolved physical systems. None of them point at proto-consciousness as a fundamental ingredient. The panpsychist can preserve compatibility with this evidence by saying “well, the proto-consciousness is still there at the fundamental level, just not doing the visible work.” Sure. So is the proto-photosynthesis, the proto-digestion, and the proto-anything-you-like. That’s not an argument; it’s a refusal to let the evidence count.

6. Panpsychism Is a Scientific Hypothesis

Now we come to (what I think is) the most underappreciated point in this whole debate.

Panpsychists like to insist they’re doing metaphysics, not physics. The phrase “philosophical theory” gets deployed as a kind of shield: you can’t refute me with experiments, because my claim isn’t an empirical one. I want to argue that this shield is illegitimate, but I want to argue it carefully - not by leaning on naive falsificationism (which my sharp interlocutors from X frequently point out is a mid-20th-century philosophy of science with problems of its own).

Look at what panpsychism actually claims:

It claims that fundamental physical entities (quarks, electrons, fields) have proto-experiential properties.

It claims that the mental properties of macroscopic systems (us, animals more broadly) are constituted by, or grounded in, the proto-experiential properties of their constituents.

It claims that the physical world has an intrinsic nature that physics describes only structurally.

Every single one of these is a claim about “what is the case in the natural world”. They are claims about the basic furniture of reality, about properties of physical entities, about the relationship between micro-physics and macro-cognition. These are precisely the kinds of claims that natural science has been making and refining ever since the late 1800s. To say “but I make these claims as a philosopher, not as a scientist” is a procedural move with no substantive content - the claims themselves don’t change category just because of who is making them.

The relevant standard here is not “panpsychism must make falsifiable predictions in the strict Popperian sense”. The relevant standard is something more like: any hypothesis that purports to describe the properties of fundamental physical entities and their relation to higher-level phenomena should engage seriously with the methods and results of the disciplines that already study fundamental physical entities and higher-level phenomena. It should integrate with physics. It should integrate with neuroscience. It should integrate with biology. It should at minimum be the kind of thing that “could in principle” be evaluated against empirical evidence, even if no current experiment is decisive. (And no - this paragraph isn’t some sort of pedantic gatekeeping. Scientific expertise matters!)

But… even by that softer, more reasonable standard, panpsychism still fails. It does not integrate with physics (the proto-experiential properties have no formalism, no Lagrangian, no role in any calculation any competent practitioner in the field does). It does not integrate with neuroscience (the entire phylogenetic and lesion-based picture of consciousness has to be relegated to “the combination problem,” which as I discussed is acknowledged to be unsolved). Panpsychism is, as we saw in section 4, deliberately constructed to be compatible with literally any physical observation.

A view that makes sweeping claims about the natural world while refusing to engage with how the natural world is actually investigated is not “doing metaphysics rather than physics.” It’s doing physics (and neuroscience) badly while claiming exemption from the standards of physics (and neuroscience). That is the actual indictment.

7. The Evidence Across Disciplines

Let’s go over the actual evidence, just to make the asymmetry more vivid.

Physics. The Core Theory accounts for every interaction relevant to the matter that makes up brains. There is no field, no force, no degree of freedom in the Standard Model that has any property recognizable as “proto-experiential.” The properties of fundamental fields are exhaustively given by their gauge structure, their masses, their couplings, their representations under the Poincaré group. Adding “experiential” properties to the list is not some small extension - it’s a wholly new kind of property with no known dynamical role and no formalism that would let us calculate with it. There is no panpsychist Lagrangian. There has never been a measurement of proto-experience. There’s not even a proposal for what such a measurement would look like, in principle.

It’s worth flagging here that some panpsychism-adjacent writers reach for the Penrose-Hameroff Orch-OR model, or the various observer-related interpretations of quantum mechanics (Wigner’s Friend, the participatory universe, etc.), as putative empirical hooks. None of these stand up. Orch-OR proposes that consciousness arises from objective wavefunction reductions in microtubules, with theoretical motivation drawn (quite controversially) from Penrose’s reading of Gödel’s incompleteness theorems. The empirical evidence for it is poor (microtubules don’t appear to maintain coherence on the relevant timescales at body temperature), the Gödelian motivation is contested by virtually every philosopher of mathematics who has weighed in on it, and even if it were true, it would establish an exotic biological mechanism, not consciousness or panpsychism. (The Wikipedia article on Orch-OR has references to the many criticisms.) Observer-related interpretations of quantum mechanics, meanwhile, are a fringe minority position even among the (already small) community of physicists who care about interpretive questions, and they don’t license panpsychist conclusions even on their own terms. The physics escape route doesn’t actually exist. (My opinion of Wheeler as a physicist actually went down a teensy bit when I first read about his participatory anthropic principle idea.)

Neuroscience. The neural correlates of consciousness are highly specific. We have well-thought out models that have and continue to be explored. Consciousness has been linked with thalamocortical activity, with global broadcasting of information across cortical hubs, with the integration of recurrent processing, with predictive processing. It can be selectively switched off by general anesthesia, which acts at specific molecular targets (GABA-A receptors, NMDA receptors, etc.) in specific circuits. Lesions to particular regions produce particular forms of consciousness loss (akinetic mutism from medial frontal damage, anosognosia from right parietal damage, blindsight from V1 damage). Decades of careful experimental work have produced a converging picture of what consciousness is, in terms of “what kind of neural activity it is”. Nothing in this picture invokes anything beyond the standard physical and biological dynamics of nervous systems.

Information theory and computation. This is the one place where I have to give the panpsychist some credit, because Tononi’s Integrated Information Theory has been openly read as panpsychism-adjacent by Tononi himself - he’s said, in print, that any system with positive integrated information has “some” degree of experience. So IIT, taken on its own terms, does seem to commit its proponents to a kind of micro-consciousness in any sufficiently integrated system, however small. This is a real challenge for a tidy physicalist position, and I don’t want to wave it away.

But two responses. First, IIT’s empirical core (the structural/architectural account of why some neural patterns are associated with consciousness and others aren’t) doesn’t actually require the panpsychist gloss. You can take the Φ formalism as a useful empirical correlate of consciousness in biological systems without granting the metaphysical claim that “any positive Φ entails some experience anywhere.” Many working neuroscientists who use IIT as a measurement framework do exactly this. Second, the panpsychist gloss on IIT runs straight into absurd consequences that panpsychism was supposed to avoid - e.g. simple grids of XOR gates have positive Φ, which means IIT-panpsychism is committed to consciousness in arbitrary computational arrangements that no one is actually willing to defend on reflection. This is a reductio in slow motion, and it’s a problem for IIT-as-metaphysics rather than for IIT-as-empirical-framework.

The other live research programs in consciousness science (Global Workspace Theory, predictive processing, higher-order theories, attention-schema theory) all do their work by building up consciousness from the structural and dynamical properties of physical systems, checking proposals against neural data, and refining. That’s the methodology of science. Panpsychism, by contrast, has no comparable program. It’s a stance, not a science.

Biology. Consciousness in the animal kingdom tracks the evolution of nervous systems with stunning consistency. Cnidarians (with nerve nets but no centralization) barely show signs of consciousness. Cephalopods (with elaborate decentralized intelligence) show many. Vertebrates with thalamocortical architecture show the canonical picture. The phylogenetic gradient is exactly what you’d expect if consciousness is a kind of biological function. Even within human development (ontogeny), consciousness develops as specific neural circuits mature - not at conception, not at the formation of the first neuron, but at the formation of the relevant integrative networks.

Chemistry. The chemistry of consciousness, to the extent it has been worked out, is the chemistry of specific molecular systems doing specific jobs. Neurotransmitters, receptors, ion channels, synaptic vesicles, glial regulation - all standard chemistry. (I learned some disturbing specifics about how chemical weapons work on the nervous system when researching this bit. Yikes.) Anesthetics are a particularly clean case: drugs that disrupt consciousness do so by interacting with specific protein targets in specific neural circuits, and the dose-response relationships are fully characterizable in standard pharmacological terms.

I think the data above in this section shows that the asymmetry is overwhelming. The scientific picture, across multiple converging disciplines, treats consciousness as a high-level functional property of specific kinds of physical systems. The panpsychist picture treats it as a fundamental property of matter that, “mysteriously”, manifests as the kind of high-level functional property the scientific picture “already captures”! The first picture does work. The second adds no value.

8. What Would Change My Mind

I am quite willing to say what would convince me. This is not an exhaustive list by any means, but a few things would do it.

1) Direct empirical evidence of proto-conscious properties affecting physics - any deviation from the Core Theory in regimes where consciousness is present, any signature of an additional dynamical degree of freedom that correlates with the presence of mind.

2) A formalism showing how proto-experience combines into rich experience, capable of generating predictions about which neural architectures should produce which kinds of conscious states, and bearing those predictions out empirically. (Would be even better if this was quantitative in some way.)

3) A successful panpsychist prediction of any neural fact about consciousness that wasn’t already entailed by ordinary physicalism.

4) A solid argument that the leading positive physicalist views are incompatible with the evidence in a way panpsychism isn’t.

I doubt that any of these are forthcoming. My objection to panpsychism is not that I refuse to consider it; it’s that, as currently formulated, it doesn’t give me anything to consider.

It’s also worth saying explicitly what the live physicalist alternatives are, because a purely negative critique invites the question “well, what’s your positive view?” I don’t have a specific preferred approach. I really like Anil Seth’s idea of predictive processing, even if I don’t like his use of the term “hallucination”. I like the GWT framework. I also like Keith Frankish’s illusionism, which I have not mentioned previously in this essay. On the illusionist view, what we call “phenomenal consciousness” - the felt, ineffable, intrinsic redness-of-red, batiness-of-bats, and so on - is itself a kind of representational illusion, generated by introspective mechanisms that misrepresent the brain’s own processing. The job of consciousness science is then to explain (a) what the brain is actually doing when we are conscious, and (b) why our introspective machinery generates the misleading impression that we have ineffable qualia. Both are tractable empirical problems. Neither requires positing fundamental experience anywhere in physics.

Anyway, the point is just that there are live, productive, “positive” physicalist views in the field. Panpsychism is not the only alternative to a confused dualism. The choice is not “panpsychism or magic.” It’s “panpsychism, or any of several research programs that have actually been making progress.”

We Have, Once Again, Confused Mystery for Evidence

I shall reiterate a point here that I’ve mentioned in prior essays. Across the history of science, there’s a recurring pattern - whenever some natural phenomenon has resisted reductive explanation, a school of thought has arisen claiming that it cannot, in principle, be explained that way, and that we must therefore add new fundamental ingredients to the world to accommodate it. Vitalism did this for life. Élan vital and entelechy were the technical terms for the alleged extra ingredient. There were sophisticated philosophers defending it. There were scientific journals in which it was respectable. And then molecular biology happened, and it turned out that life could be entirely explained by chemistry and information after all.

(Here I should point out that vitalism, in its strongest forms, actually made specific empirical claims that got refuted - Wöhler’s 1828 synthesis of urea from inorganic precursors being the famous early shot. Panpsychism, by contrast, makes no comparably specific claims. So the analogy is imperfect: vitalism was wrong because it could be checked; panpsychism is in worse shape because it can’t be. But the meta-pattern is the same.)

I argued in my piece on fine-tuning that the fine-tuning argument trades on a similar move: identify a real but currently unsolved problem in physics, declare the problem unsolvable in principle, and insert a metaphysical answer (in that case, God). The structure of the panpsychist argument is identical. It identifies a real but currently unsolved problem in cognitive neuroscience (how does the brain produce experience?), declares the problem unsolvable in principle, and inserts a metaphysical answer (consciousness is fundamental). In both cases, the substitution feels profound but does no actual explanatory work. In both cases, the move has no track record - the history of science is a graveyard of similar substitutions.

That is the deepest indictment of panpsychism. It confuses the “difficulty” of a problem with the “impossibility” of a problem. It mistakes our current ignorance for an ontological barrier. It dresses up a confession of (temporary) inability as some sort of deep metaphysical insight. And then, having made a series of claims about the basic nature of physical reality, it asks to be evaluated by the standards of philosophy rather than science - which is a methodological move that should, by itself, raise alarms (and hackles).

The Bottomline

Panpsychism is what happens when you take an interesting intuition (you can’t get experience from non-experience), apply it once, and then stop. If you apply it again, it eats itself. The unification of micro-experiences into a single perspective is not less mysterious than the production of experience from neural activity - it’s “more” so, because the very anti-emergence principle that motivated the position now forbids the unification step too. The Core Theory constraint forces panpsychism into an unwinnable choice between being empirically false and being explanatorily empty; the Russellian “intrinsic nature” reply is clever but leaves the proto-experiential characterization doing no work that “neutral categorical basis” wouldn’t do equally well. The phylogenetic gradient of consciousness in the natural world makes proto-experience explanatorily idle. The convergence of evidence from physics, neuroscience, biology, and chemistry pushes overwhelmingly in the same direction. And critically - panpsychism is not, despite the conventional framing, a philosophical hypothesis insulated from empirical evaluation. It is a hypothesis about the basic furniture of reality, and as such, it is squarely in the wheelhouse of natural science. By the standards of any serious empirical theory, it is unmotivated, untestable in any productive sense, and explanatorily inert.

(We still have a hard problem of neuroscience - related to understanding exactly how the nervous system works. But as mentioned above, work on that has been fruitful and will continue until we figure it out.)

Also, as I mentioned in my essay on the hard problem of consciousness, the actual hard problem is not really that hard once you take the explanatory gap to be a feature of our description rather than of reality. As such, we should expect this to be solved (or more accurately dissolved) the way every other apparent metaphysical puzzle in the history of natural science has been solved: by patient empirical work. By figuring out what the brain actually does, how it does it, and why those particular operations look the way they do from the inside.

Final Thoughts

I’ve tried to make the case that consciousness isn’t built into the universe. It’s something the universe occasionally pulls off, in places where the material conditions are right. That’s already remarkable enough.