The physicist Sean Carroll was recently on the Mind Chat podcast hosted by the philosophers Keith Frankish and Philip Goff. Watch it here.
Earlier today, Carroll uploaded a blog post to tie up some loose ends after his discussion with Goff and Frankish: “The Zombie Argument for Physicalism (Contra Panpsychism).”
Contrary to the intent of most philosophical zombie arguments, Carroll attempts to “ZAP” the credibility of panpsychist accounts of consciousness by arguing that, ironically, the well-wrought thought experiment only ends up strengthening the case for physicalism.
Philosophical zombies would, of course, insist that they have 1st-person introspective acquaintance with their own inner lives. They would claim to enjoy colors and sounds, and to feel deeply insulted by our opinion of them as mere mindless automatons. But they would be completely mistaken. Their verbal objections to our genuinely conscious judgements about them would amount to nothing more than the causally determined motion of lips, tongue, vocal cords, diaphragm, and neurons. No one would be making the claims, as they would amount to no more than the auditory outputs of a complicated machine.
Carroll correctly claims that the traditional zombie argument, if it challenges the credibility of physicalism at all, leaves panpsychists with a merely epiphenomenal sort of consciousness, a witness with no will, a ghost with no way to actively participate in physical processes. Admitting that consciousness is epiphenomenal leaves the panpsychist with way less explanatory leverage against physicalism, since if consciousness makes no difference to the goings-on of the physical world, then scientifically speaking it’s just not worth bothering about. Carroll admits that dualists could still argue for the irreducibility of epiphenomenal consciousness to physics, but due to the incoherence of the dualist ontology (i.e., two entirely distinct types of substance with no clear way to interact), we can set this position to the side.
If, on the other hand, consciousness does have some strongly emergent, downward causal role to play in how the body behaves, then according to Carroll that would mean that the very well-established Core Theory of physics is wrong. Electrons can’t break the laws of physics just because the mind haunting my brain tells them to.
In the background is Carroll’s claim to possess a complete theory by means of which the behavior of the physical world can be deduced.* The problem with this sort of model-centrism is that it entirely neglects the historicity of our universe, implying some sort of outside “God’s eye view.” Carroll’s emphasis on timeless imposed laws begs the question of their status in an otherwise entirely materialistic cosmos. Like Lee Smolin, and earlier philosophical scientists like C. S. Peirce and A. N. Whitehead, I find it more coherent to recognize the cosmos as an evolving process, with “laws” arising as widespread habits alongside the emergent entities exemplifying them. As the cosmos complexifies, emergent entities like atoms, stars, and galaxies take shape to progressively constrain the future course of evolution. But nothing in the Core Theory, as I understand it, predicts the emergence of life or mind. This is not to say that the Core Theory somehow rules out the possibility, just that it renders these phenomena exceedingly unlikely, even miraculous. For the Core Theory to be considered a truly complete theory of everything, it would need to account for its own conditions of possibility, which is to say it would need to describe a universe wherein creatures capable of developing a Core Theory could evolve. Short of this, the best we cay say about the theory is that it accurately describes the goings-on of its particular domain of relevance. It is an abstract model that describes the physical world as if life and mind did not exist. Bracketing these higher level phenomena for the purposes of developing workable models of simpler phenomena is perfectly fine. Physics has been wildly successful in doing so! But turning around to try to explain away the consciousness doing the explaining as though it were nothing but a “successful way of talking” about physical behavior reeks of model-centrism.
Now, to be clear, I am not suggesting that conscious agency in any way contradicts the account of particles and fields offered by the Core Theory. Electrons, for instance, need not disobey the equations of physics to nonetheless be subject to different probability distributions resulting from the unique, highly evolved physiological environment of the mammalian nervous system. The point is that context matters. Laws are not imposed on nature from some eternal mathematical heaven. They are descriptions of the statistical behavior of entities in various environments and at various levels of organization.
But back to the zombie argument. The point of this thought-experiment, as I understand it, is not to prove that consciousness is necessarily something extra above and beyond physics. Nor am I convinced by Carroll’s ironic reversal, that somehow it cements the strength of the physicalist account. I think it is helpful to cut to the chase by putting the zombie argument in an evolutionary context. If consciousness evolves, then it cannot be epiphenomenal, since in that case it would play no role in an organism’s behavior and thus offer nothing for the evolutionary process to select and enhance. So, if we put dualism and idealism to the side (I know this is not entirely fair to idealists, but that discussion will have to wait for a later post), then consciousness must somehow be causally efficacious, i.e., it must be a real feature of the physical world. But if matter/energy is construed in the abstract terms that model-centrists insist upon, then it is not at all clear how to bridge the gap. Hence Chalmers’ “hard problem.”
The solution, I’ve argued, is to first admit that physics offers a highly predictive but nonetheless abstract account of the isolated behavior of fields and particles. There is nothing in this model that suggests the universe should ever come to life or wake up and start consciously reflecting upon itself. Thus, the model needs to be placed in a broader cosmological context. To resolve the hard problem of consciousness, what we have traditionally meant by “matter” and by “experience” needs to be rethought, such that the two are understood as the “outside” and the “inside” of one and the same unfolding reality. This allows us to make continuous what would otherwise remain a rather glaring ontological chasm.
That simpler forms of self-organization, like electrons, protons, or the atomic elements they symbiotically compose, follow extremely regular and predictable patterns of behavior does not rule out the possibility that these behaviors are the expression of what Whitehead described as “vector-feelings.” What physicists describe in mathematical terms as gravitational fields may be experienced by the particles in question as gravitational feelings.
*For a logical and philosophical critique of Carroll’s “Core Theory,” see pgs. 126-130 of plasma physicist and process philosopher Tim Eastman’s book Untying the Gordian Knot: Process, Reality, and Context (2020).
For an article length treatment of these issues, see “The Varieties of Physicalist Ontology: A Study in Whitehead’s Process-Relational Alternative” (2020)