What should we expect out of a theory of consciousness?
For a scientific theory of consciousness to have even the slightest chance at being correct it must be able to address- at the very least– the following four questions*:
- Why consciousness exists at all (i.e. “the hard problem“; why we are not p-zombies)
- How it is possible to experience multiple pieces of information at once in a unitary moment of experience (i.e. the phenomenal binding problem; the boundary problem)
- How consciousness exerts the causal power necessary to be recruited by natural selection and allow us to discuss its existence (i.e. the problem of causal impotence vs. causal overdetermination)
- How and why consciousness has its countless textures (e.g. phenomenal color, smell, emotions, etc.) and the interdependencies of their different values (i.e. the palette problem)
In addition the theory must be able to generate experimentally testable predictions. In Popper’s sense the theory must make “risky” predictions. In a Bayesian sense the theory must be able to generate predictions that have a much higher likelihood given that the theory is correct versus not so that the a posteriori probabilities of the different hypotheses are substantially different from their priors once the experiment is actually carried out.
As discussed in a previous article most contemporary philosophies of mind are unable to address one or more of these four problems (or simply fail to make any interesting predictions). David Pearce’s non-materialist physicalist idealism (not the schizophrenic word-salad that may seem at first) is one of the few theories that promises to meet this criteria and makes empirical predictions. This theory addresses the above questions in the following way:
(1) Why does consciousness exist?
Consciousness exists because reality is made of qualia. In particular, one might say that physics is implicitly the science that studies the flux of qualia. This would imply that in fact all that exists is a set of experiences whose interrelationships are encoded in the Universal Wavefunction of Quantum Field Theory. Thus we are collapsing two questions (“why does consciousness arise in our universe?” and “why does the universe exist?”) into a single question (“why does anything exist?”). More so, the question “why does anything exist?” may ultimately be solved with Zero Ontology. In other words, all that exists is implied by the universe having literally no information whatsoever. All (apparent) information is local; universally we live in an information-less quantum Library of Babel.
(2) Why and how is consciousness unitary?
Due to the expansion of the universe the universal wavefunction has topological bifurcations that effectively create locally connected networks of quantum entanglement that are unconnected to the rest of reality. These networks meet the criteria of being ontologically unitary while having the potential to hold multiple pieces of information at once. In other words, Pearce’s theory of consciousness postulates that the world is made of a large number of experiences, though the vast majority of them are incredibly tiny and short-lived. The overwhelming bulk of reality is made of decohered micro-experiences which are responsible for most of the phenomena we see in the macroscopic world ranging from solidity to Newton’s laws of motion.
A few of these networks of entanglement are us: you, right now, as a unitary “thin subject” of experience, according to this theory, are one of these networks (cf. Mereological Nihilism). Counter-intuitively, while a mountain is in some sense much bigger than yourself, at a deeper level you are bigger than the biggest object you will find in a mountain. Taking seriously the phenomenal binding problem we have to conclude that a mountain is for the most part just made of fields of decohered qualia, and thus, unlike a given biologically-generated experience, it is not “a unitary subject of experience”. In order to grasp this point it is necessary to contemplate a very extreme generalization of Empty Individualism: not only is it that every moment of a person’s experience is a different subject of experience, but the principle applies to every single network of entanglement in the entire multiverse. Only a tiny minority of these have anything to do with minds representing worlds. And even those that participate in the creation of a unitary experience exist within an ecosystem that gives rise to an evolutionary process in which quintillions of slightly different entanglement networks compete in order to survive in the extreme environments provided by nervous systems. Your particular experience is an entanglement network that evolved in order to survive in the specific brain state that is present right now. In other words, macroscopic experiences are the result of harnessing the computational power of Quantum Darwinism by applying it to a very particular configuration of the CNS. Brain states themselves encode Constraint Satisfaction Problems with the networks of electric gradients across firing neurons in sub-millisecond scales instantiating constraints whose solutions are found with sub-femtosecond quantum darwinism.
(3) How can consciousness be causally efficacious?
Consciousness exerts its causal power by virtue of being the only thing that exists. If anything is causal at all, it must, in the final analysis, be consciousness. No matter one’s ultimate theory of causality, assuming that physics describes the flux of qualia, then what instantiates such causality has to be this very flux.
Even under Eternalism/block view of the universe/Post-Everettian QM you can still meaningfully reconstruct causality in terms of the empirical rules for statistical independence across certain dimensions of fundamental reality. The dimensions that have time-like patterns of statistical independence will subjectively be perceived as being the arrows of time in the multiverse (cf. Timeless Causality).
Now an important caveat with this view of the relationship between qualia and causality is that it seems as if at least a weak version of epiphenomenalism must be true. The inverted spectrum thought experiment (ironically usually used in favor of the existence of qualia) can be used to question the causal power of qualia. This brings us to the fourth point:
(4) How do we explain the countless textures of consciousness?
How and why does consciousness have its countless textures and what determines its interrelationships? Pearce anticipates that someday we will have a Rosetta Stone for translating patterns of entanglement in quantum fields to corresponding varieties of qualia (e.g. colors, smells, sounds, etc.). Now, admittedly it seems far fetched that the different quantum fields and their interplay will turn out to be the source of the different qualia varieties. But is there something that in principle precludes this ontological correspondence? Yes, there are tremendous philosophical challenges here, the most salient of which might be the “being/form boundary”. This is the puzzle concerning why states of being (i.e. networks of entangled qualia) would act a certain way by virtue of their phenomenal character in and of itself (assuming its phenomenal character is what gives them reality to begin with). Indeed, what could possibly attach at a fundamental level the behavior of a given being and its intrinsic subjective texture? A compromise between full-fledged epiphenomenalism and qualia-based causality is to postulate a universal principle concerning the preference for full-spectrum states over highly differentiated ones. Consider for example how negative and positive electric charge “seek to cancel each other out”. Likewise, the Quantum Chromodynamics of quarks inside protons and neutrons works under a similar but generalized principle: color charges seek to cancel/complement each other out and become “white” or “colorless”. This principle would suggest that the causal power of specific qualia values comes from the gradient ascent towards more full-spectrum-like states rather than from the specific qualia values on their own. If this were to be true, one may legitimately wonder whether hedonium and full-spectrum states are perhaps one and the same thing (cf. Valence structuralism). In some way this account of the “being/form boundary” is similar to process philosophy, but unlike process philosophy, here we are also taking mereological nihilism and wavefuction monism seriously.
However far-fetched it may be to postulate intrinsic causal properties for qualia values, if the ontological unity of science is to survive, there might be no other option. As we’ve seen, simple “patterns of computation” or “information processing” cannot be the source of qualia, since nothing that isn’t a quantum coherent wavefunction actually has independent existence. Unitary minds cannot supervene on decohered quantum fields. Thus the various kinds of qualia have to be searched for in networks of quantum entanglement; within a physicalist paradigm there is nowhere else for them to be.
I am very open to the possibility that other theories of consciousness are able to address these four questions. I have yet to see any evidence of this, though. But, please, change my mind if you can! Does your theory of consciousness rise to the challenge?
* This particular set of criteria was proposed by David Pearce (cf. Qualia Computing in Tucson). I would agree with him that these are crucial questions; indeed they make up the bare minimum that such a theory must satisfy. That said, we can formulate more comprehensive sets of problems to solve. An alternative framework that takes this a little further can be found in Michael Johnson’s book Principia Qualia (Eight Problems for a New Science of Consciousness).