Not only does panpsychism have questionable value as a philosophical hypothesis; not only is it flat-out refuted by empirical science; but even the very intuitions that motivate panpsychists turn out to be based on unexamined assumptions mistaken for facts, writes Bernardo Kastrup.

In a world increasingly confronted with the contradictions of physicalism, an alternative metaphysics has become popular in academia: panpsychism. Many different theories go by this term, but most people associate it with what is technically called ‘constitutive micropsychism’: the notion that elementary subatomic particles (henceforth simply ‘particles’), in addition to physical properties such as mass, charge and momentum, also have fundamental experiential properties. In other words, the hypothesis is that there is something it is like to be an electron, or a quark, and that no explanation is required for their consciousness because the latter is irreducible. According to constitutive micropsychism (henceforth simply ‘panpsychism’), the experiential properties of the particles constituting our brain somehow combine to give rise to higher-level human consciousness.

The appeal of panpsychism is that, while preserving the physicalist notions that (a) matter has standalone existence and (b) material arrangements are responsible for human-level consciousness, it avoids the famous ‘hard problem’ by making lower-level consciousness fundamental. Notice, however, that instead of enhancing the explanatory power of physicalism, this merely avoids the need for an explanation by throwing one more element—namely, low-level consciousness—into the reduction base, while removing nothing from it. It can thus be argued that panpsychism is as arbitrary as it is unhelpful, for it would be trivial to ‘solve’ every metaphysical problem simply by declaring every aspect of nature to be fundamental.

Another philosophical shortcoming of panpsychism is that there is no explicit, coherent account—not even in principle—of how two or more fundamentally distinct subjects of experience can combine to form a higher-level one. How can the little subjectivities of the myriad particles constituting your brain combine to give rise to you as a conscious subject? After all, your neurons don’t even touch one another, their communication is taking place through neurotransmitter molecules that drift across the gaps between them. As a matter of fact, a compelling case has been made that the combination of otherwise separate fields of subjectivity is an incoherent concept; as much a hand-waving appeal to magic as attempts to solve the hard problem.

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Physically speaking, panpsychism simply cannot be true.

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SUGGESTED READING Consciousness Cannot Have Evolved By Bernardo Kastrup The philosophical shortcomings of panpsychism, however, are rendered redundant by a simple scientific fact: panpsychism contradicts known physics and is, therefore, demonstrably false. Indeed, the foundational premise of panpsychism is that particles are entities with discrete spatial boundaries, like little marbles localised in space. This is supposedly the reason why the little marbles inside your head combine to form your consciousness, while the little marbles inside my head, in a different spatial location, combine to form my consciousness, separate from yours. The spatial boundaries of our respective marbles render your experiential field disjoint from mine, thereby preventing us from accessing the contents of each other’s minds—or so the story goes.

But we’ve known at least since the late 1940s (arguably even as early as the late 1920s), with the advent of quantum electrodynamics, that what we call ‘particles’ aren’t particles at all: they are merely local patterns of excitation of a spatially unbound quantum field. Think of ‘particles’ as ripples on a lake: each ripple has a certain height, thickness, speed and direction of movement, which are the ripple’s defined physical properties. They also have defined locations in space: you can point at a part of the lake and say, “there’s a ripple!” Yet, there is nothing to the ripple but the lake itself. The ripple is not a standalone entity, but a behaviour of the lake; it’s not a thing but a ‘doing.’ This is why you cannot grab a ripple and lift it off the lake.

In precisely the same way, Quantum Field Theory (QFT)—the more general formulation of quantum electrodynamics, which also happens to be the most accurate scientific theory ever devised—tells us that the so-called particles are just ‘ripples’ of a quantum field. In essence, there are no true particles; we use this word today only metaphorically, and for historical reasons. There are only quantum fields, which are spatially unbound.

Therefore, if the panpsychist wants to avoid the ‘hard problem’ by making consciousness a fundamental property of an irreducible physical entity, then only a field can be that entity. It is the field that must be conscious, not a ‘particle,’ for there’s nothing to the particle but its associated field.

The problem, of course, is that the same quantum fields span the space occupied by your body and mine. So why can’t I read your thoughts and you mine? How can our respective experiential fields be disjoint, if the same quantum fields underly—as they do—you and me? Panpsychism implodes the moment it is rendered in a physically consistent manner.

SUGGESTED READING What physicists get wrong about consciousness By Philip Goff Some panpsychists seek refuge from this argument in Bohmian mechanics, a niche interpretation of quantum mechanics that preserves the marble-like nature of particles. But this only reflects a continued lack of familiarity with contemporary physics. Even if Bohmian mechanics hadn’t been experimentally refuted a few years ago, it does not have a relativistic extension to reconcile it with special relativity. This alone renders it untenable, for relativity has been experimentally confirmed ad nauseum. Indeed, it can be argued that any formulation of quantum mechanics that can be reconciled with relativity will entail a field-excitation understanding of particles. It is also this field-excitation understanding that allows QFT to make sense of a great many empirically observed phenomena, such as the spontaneous appearance and disappearance of particles in a vacuum—the so-called quantum fluctuations—which would amount to magic if particles truly were little marbles. Finally, Bohmian mechanics has been renounced by its very creator—Louis de Broglie—already a century ago. Appeals to Bohmian mechanics just make the panpsychist look silly.

Even if we set the insights of QFT aside, the very notion that particles have a standalone existence—as opposed to being derivative or epiphenomenal—is now seriously called into question in the foundations of physics. A 40-year-long series of repeated experiments has shown that the physical properties of a particle depend on what one chooses to measure about another, entangled particle far away. In other words, what the particle is depends on measurement choices; the physical properties that define the particle are not there prior to measurement. Short of woo theoretical fantasies like (a) bazillions of invisible parallel universes being created every infinitesimal fraction of a second, and (b) the undetermined ‘hidden variables’ of superdeterminism—neither of which has an iota of direct empirical substantiation, despite being highly inflationary hypotheses—we are forced to conclude that particles somehow arise from measurement. As such, and contrary to the naïve premises of panpsychism, particles are not fundamental. Physically speaking, panpsychism simply cannot be true.

With this question settled, we can now explore a more interesting and productive one: what are the intuitions that render panpsychism so appealing to some and what, precisely, is wrong about them?

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The panpsychist mistakes the structure of the contents of perception for the structure of the perceiver. Conflating these two things leads to category mistakes.

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The core of the panpsychist’s intuition is that we, subjects of experience, are compound entities. In other words, we are seemingly made of proper parts, such as discrete living cells, put together to form our body and brain. Moreover, those cells are themselves compound entities as well, in that they are constituted of numerous particles put together. As such, our very consciousness—or so the intuition goes—must also be compound, somehow arising from the combination of lower-level constituents.

More than one unexamined assumption, mistakenly taken for fact, underly this intuition. For starters, that the body is a compound structure does not entail or imply that the subjectivity associated with the body is itself compound. The body is a perceptual representation: a thing we see, feel, smell, etc. But the structure of representations on the screen of perception is not necessarily the structure of the subject of perception. Allow me to repeat this for clarity. The panpsychist mistakes the structure of the contents of perception for the structure of the perceiver. Conflating these two things leads to category mistakes.

To see why, consider the following example: if I were to talk to you remotely, via a video call, you would see me represented on your phone’s screen as a pixelated image. In it, I’d look like the compound result of tiny rectangular blocks put together. But that doesn’t mean that I, Bernardo Kastrup, am made of tiny rectangular blocks. The pixelation is an artifact of my representation on a screen, not my inherent structure as that which is represented.

Now, for precisely the same reason, that the structure of a body—a representation of a subject on the screen of perception—is compound, doesn’t entail or imply that the subject represented as the body is itself compound. Particles are the pixels of the screen of perception, not necessarily the building blocks of subjects. The structure of the representations isn’t necessarily the structure of the represented, and so we cannot conclude that subjects are made of particles; only bodies are.

You may think that these are very abstract and remote considerations, but they constitute the very metaphysical ground where panpsychism germinated and derives its relevance from. Thus, bear with me.

Unlike particles, cells are living entities just as we are. For this reason, the cellular structure of our brain may seem, intuitively, to be a more compelling sign that our consciousness must itself be compound. After all, there is a certain equivalence between individual cells and our organism as a whole: both are alive and metabolize. As such, if I am conscious, so must the cells that constitute my brain be, and panpsychism is true—or is it?

Compelling as it may sound, this line of reasoning also relies on an unexamined assumption, mistaken for fact. Specifically, when we think of the body as a compound entity just because it seems to be made of many cells, we are conflating growth with assemblage, and thereby mistakenly taking for granted that our cells are proper parts of us. Allow me to unpack this.

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There is, thus, an important sense in which a person—along with her brain—is not ‘made of’ cells.

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An entity is assembled when its structure is defined from the outside in, as determined by how its constituent parts are brought together. A car is assembled, because its structure is defined by engineers and realised by welding its parts together in an assembly line. A living organism, on the other hand, isn’t assembled; instead, it grows. In growth, the structure of the entity is defined from the inside out: raw materials still flow in, but their place and role in the organism are defined from within. An organism isn’t assembled; its structure is defined by its own inner being.

Only assembled entities can be confidently said to be compound, and thus to have proper parts. Growth, on the other hand, can be coherently interpreted as a process of inner structuring or inner complexification, in which the only part is the whole thing. A human being begins life as a zygote—a fertilized egg—which complexifies itself internally, in a self-similar or fractal manner, through what we call mitosis, or cell division. A fully grown person can be coherently regarded as still being the original, non-compound, unitary zygote; just one that has complexified itself internally to a large degree.

There is, thus, an important sense in which a person—along with her brain—is not ‘made of’ cells; instead, the cells are simply what the inner complexification of the person, through growth, looks like. Regarding cells as proper parts is, at best, merely nominal.

A human zygote just after fecundation (left) and three days later (right). Are the eight cells of the three-day-old embryo (right) proper parts of a new compound entity, or merely the inner structuring, or inner complexification, of the original zygote (left)?

As such, the cell structure of our body isn’t a reason for us to think of ourselves as compound entities, or of our consciousness as made of proper parts. It means only that the unitary entity we have always been, since the moment of fecundation, has developed a complex inner structure over time, through growth. To disagree with this is to fail to recognize the reason why we never say that a car grows, or a person is assembled.

SUGGESTED READING Why Materialism is a Dead-End By Bernardo Kastrup Indeed, everything about how our body works tells us that we, unlike a car, aren’t truly compound entities: the cells in our body ‘know’ exactly how they need to shape themselves, and what they need to do, depending on where in the body they are located. Their form, activity and very existence are coordinated by a global, unitary pattern. Moreover, all of our cells share identical instances of this still-mysterious thing we call DNA, which is the physical clue that they aren’t proper parts of a compound entity, but merely the fractal inner structure—complexified through growth—of one irreducible whole. When cells actually behave as parts, we say that they’ve become cancerous.

In conclusion, not only does panpsychism have questionable value as a philosophical hypothesis; not only is it flat-out refuted by empirical science; but even the very intuitions that motivate panpsychists turn out to be based on unexamined assumptions mistaken for facts. Panpsychism isn’t the future of metaphysics; it’s just the still-born baby of an attempt to put continuity—that is, the safeguarding of at least some aspects of physicalism—above reason and above evidence.