I know little about philosophy and I've been reading into consciousness. From an uneducated view, David Pearce's argument seems strong.


What arguments would you raise to question it? He also claims it's testable to find "neuronal superpositions with matter-wave interferometry", unlike other theories which (correct me if I'm wrong) seem impossible to test! I know that people here can't write about every little thing on that page and the many others he has written on his ideas, but at least some questioning on his ideas would be nice, especially by people who know quantum mind theory and David Pearce's work well.

Theories of consciousness to recommend me that you find equally strong are welcome. I will also edit to link a shorter abstract if anyone can find me one so it'll take less time to read.

  • 3
    1) the brain is too warm to support much quantum computation 2) the successes of deep neural networks, such as ChatGPT, at imitating much of the functionality of the human brain suggests that no quantum computation is needed to produce humanlike behavior; just big, classical neural networks are enough.
    – causative
    Jan 2 at 10:11
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    – Community Bot
    Jan 2 at 11:43
  • @causative -- Pearce has addressed the brain warmth issue. See section 4.3 biointelligence-explosion.com/parable.html
    – Dcleve
    Jan 2 at 18:40
  • @Dcleve Utter nonsense. Section 4.3 offers no physics-based argument for how quantum coherence could occur with the brain so warm. Instead it suggests, ridiculously, that a decoherence time of 10^-15 seconds would mean that consciousness is "running" at 10^15 "frames" per second - as if decohering faster was somehow a good thing for quantum computation! If decoherence happens that fast, there's no time to do any type of calculation. The qubits don't have time to interact with each other.
    – causative
    Jan 2 at 19:53
  • @causative -- untrue. Pearce cites Tegmark for the timescale limitations for quantum decorrelation. space.mit.edu/home/tegmark/brain.pdf And no, he does not argue that decohering faster is a GOOD thing for his speculation. He instead tries to find a way around what he admits is a problem. His answer has major flaws, just not the one you were pointing out.
    – Dcleve
    Jan 2 at 20:04

4 Answers 4


You were 100% correct when you surmised that people here can't write about every little thing on Pearce's page- my eyes glazed over before I finished its first paragraph. There are two main reasons why the idea of a quantum mind is easy to dismiss if you are that way inclined. One is that the more exotic quantum effects are hard to sustain at scale outside of a laboratory, because they get scrambled by the noise inherent in real stuff such as the material brains are made of. The second is that there isn't a compelling theory that explains why and how quantum effects lead to consciousness. As Pearce says, it's as if people have spotted a common degree of inexplicable weirdness in quantum theory and consciousness and assumed that they might therefore be related.

  • Your last two sentences are spot on. I mean, the whole thing is, but those in particular.
    – TKoL
    Jan 2 at 12:41
  • Pearce appears to have addressed your concern over decorrelation. His proposal is that consciousness operates as a much shorter time frame, where neurons can be correlated. That he does not have a mechanism yet -- is common to ALL theories of consciousness. Do you dismiss all other speculations in Philosophy of Mind as well? I give Pearce massive credit for at least coming up with a method to test his speculation in theory (see section 6: physicalism.com/#6)
    – Dcleve
    Jan 2 at 18:37
  • @Dcleve I wonder what we do with the trillions of cycles of activity that his much shorter time frame envisages to happen in the time it takes for us to make a decision. Jan 2 at 19:08
  • @MarcoOcram -- the time-frame mismatch between his proposed mechanism for consciousness, and the data we have from consciousness studies, is a huge black mark for his speculation. He did, however, propose this in response to the decorrelation time issue you cited. It is best to address his actual theory, which was already patched to deal with the objection you posted.
    – Dcleve
    Jan 2 at 19:59

I consider the argument weak.

As I read the argument it consists of:

  1. Ontological physicalism must be true (this is the first step of Strawson's argument)
  2. Strawsonian physicalism is the only way to do science and treat consciousness as real (Strawson's second step)
  3. Computationalism and all other more traditional forms of physicalism lead to zombiehood relative to consciousness, hence we must find some other feature of physicalism that allows for consciousness to be real and causal.
  4. The only such option is quantum consciousness
  5. Because of decorrelation, if QC is real, it has to operate at a very short timeframe, and this is a credible possibility

Reviewing the points above:

Point 1 is -- highly suspect. Physics is a field of study, not an ontology. "Ontological physicalism" is a good example of a category error. Hempel's Dilemma points this out, and has to my knowledge not been "solved" by any ontological physicalist. Plus -- physics requires information and principles -- neither of which are physical. Ontologic physicalism must, to be complete, be a dualist ontology, with both matter and abstractions both central features of our world.

There are lots of other ontologies that are actually ONTOLOGIES that are preferable to "ontological physicalism". Strongly emergent materialism, Popper's 3 worlds, Interactive dualism, strongly emergent idealism -- all are coherent ontologies, and therefore are far more credible.

Point 2 is simply a false dichotomy. All of the alternatives in paragraph 2 under point 1 allow us to do science.

Point 3 is actually true, but Pearce does not provide the rationale to defend it. The rationale is that evolutionary variation then selection would have eliminated the causally irrelevant consciousness of the traditional physicalist theories. Only theories that hold consciousness to be causal are compatible with evolution. A physicalist can still hold by strongly emergent physicalism, which is where most physicalists have gone relative to consciousness. Strawson does not consider strong emergence to be credible, which is why he is casting about for another alternative.

Point 4 is unsupported. How or why quantum consciousness solves the problems with digital computers or functionalism, is unstated in his link. We could do functions thru quantum coherence, and this quantum functionalism is no more plausibly conscious than our current digital computers are.

Point 5 is weak. We have very good confidence that our consciousness functions operate well beyond the timeframe that he postulates quantum consciousness operating at. A possible phenomenon that is off by orders of magnitude from the timescale we have for consciousness, is not a credible candidate for the source/explanation of consciousness. If he really wants to focus on quantum effects, he would be far better off working with limited entanglement rather than whole-brain correlation. Limited entanglement CAN be sustained thru the time scales of consciousness. But this would still suffer from "and how does this solve the problem" questions.

So -- I am not buying his pitch here.

Strong emergence, or interactive spiritual dualism, or emergent dualism -- these are three options that Pearce and Strawson are not considering, all of which can explicitly solve the hard problem by noting that consciousness performs a causal function for us.

  • Do you have any resources that can explain those three things in the last paragraph? Also what do you mean causal function? What is a pain-pleasure or value/disvalue axis and why does Pearce claim nonbiological consciousness would lack one?
    – Terra
    Jan 3 at 0:03
  • Karl Popper's model in The Self and Its Brian is an emergent dualist model. John Eccles model in How the Self Controls Its Brain is an interactive dualist model. I am not a fan of strong emergent phyicalism, as I think it is a non-sequitur. I do not have a specific author to recommend, maybe others will suggest one?
    – Dcleve
    Jan 3 at 0:06
  • @Terra Hmm. I will offer a strong emergentist physicalist as an example, Gregg Enriques. Here is a summary of his views: medium.com/unified-theory-of-knowledge/…
    – Dcleve
    Jan 3 at 1:17
  • Thanks for the resources. Comments aren't for extended discussion, so I'll end it here. What about the pain-pleasure/value-disvalue axis? I don't quite get his argument for why nonbiological consciousness would lack one.
    – Terra
    Jan 3 at 1:55
  • @Terra -- the essay is long, and I just focused on the small section your question was about. In a quick skim, I was not able to find the value/disvalue axis discussed by Pearce. My own view is that AI could do everything that we use consciousness to do -- there is no intrinsic need to engage consciousness to do intelligence, and value/disvalue can be done without qualia too. WE use consciousness and qualia in steering, which really only makes sense in a dualist worldview. Our AI need not bother.
    – Dcleve
    Jan 3 at 2:32

May I make a couple of general comments.

(1) If you don't believe that phenomenal binding is classically impossible, then none of my speculations on quantum mind will be remotely of interest nor worth experimentally falsifying. They are far-fetched. But given textbook neuroscience, phenomenal binding is mystifying. Assume that we are packs of effectively classical neurons. If so, then why aren't we (at most) just micro-experiential zombies, just patterns of membrane-bound neuronal “mind-dust”? How could 86 billion or so membrane-bound micro-pixels of experience create a mind, a phenomenally-bound subject of experience running a real-time world-simulation (what naive realists call “perception”) like the one you instantiate now?

(2) If you don't take seriously what philosophers call the intrinsic nature argument (cf. https://www.hedweb.com/quora/2015.html#nonmat) as a possible solution to the Hard Problem of consciousness, then none of my speculations on quantum mind will remotely be of interest nor worth experimentally falsifying either. For if (as common sense suggests) the world's fundamental quantum fields are intrinsically non-experiential, then there is no experience phenomenally to bind in the first instance. Invoking quantum theory won’t help turn water into wine.

However, if you're still with me, then a “Schrödinger neurons" conjecture is worth experimentally (dis)confirming. As far as I can tell, “cat states” are all one ever knows. “Cat states” make the experience of definite outcomes possible (cf. https://www.hedweb.com/quora/2015.html#fearwords). Note that what’s most counterintuitive about the conjecture isn't the proposed existence of neuronal superpositions - even individual superpositions of distributed neuronal feature-processors. For if neuronal superpositions were ever proven experimentally not to exist, then physics would be rocked to the core. Even the slightest departure from the unitary Schrödinger dynamics would involve some sort of a “dynamical collapse” theory, i.e. radically new physics. Here at least I’m boringly orthodox. Rather, the reason that most physicists would reject a “Schrödinger's neurons" conjecture out of hand - as likewise would educated laymen who understand decoherence - is simply that the effective lifetime of neuronal superpositions in the CNS is far too short - femtoseconds or less, i.e. irrelevant psychotic noise.

Well, maybe. Let's use interferometry to find out!

  • David I'm so glad you replied, I've been trying to get into contact with you and I enjoy your hedonistic imperative. I hope you can reply to other answers here to give your take. Do you have any way we can speak further on this?
    – Terra
    Jan 4 at 5:58
  • Terra, thank you. I like to stress HI is dissociable from my highly speculative conjectures on quantum mind. But they aren't unrelated. For instance, if I'm right about the non-classicality of phenomenal binding, then we don't need to worry about LLMs, implementations of classical Turing machines and classical computers in general ever "waking up", let alone suffering. Digital mind is an oxymoron. But we need to make sure that we get our theory of consciousness - if not right - at least not catastrophically wrong. Jan 4 at 8:51
  • Okay, what about a method of contacting you so we can speak in more detail? I know very little on this topic and on this site it's forbidden to have extended discussion in comments
    – Terra
    Jan 4 at 9:06
  • Terra I'm new here too. I tried to comment on the other answers, but the system wouldn't let me. Apologies. Perhaps try The Hedonistic Imperative Facebook group. Jan 4 at 9:27
  • [I couldn't post this response to an answer above] First an apologetic note about terminology. The position I explore, non-materialist or idealist physicalism, has obvious affinities with Strawson's. "Strawsonian physicalism" also sounds more austere - particularly to the ears of older people who confuse Galen with his illustrious father, Sir Peter. But I subsequently discovered that Galen Strawson is a perceptual direct realist. IMO, direct realism is radically mistaken. So I now stick to "non-materialist physicalism". Jan 4 at 9:30

The habit of the human mind is to assign essences. Aristotle had his. The doctrine was given a face lift by Locke when he moved forward with explicating on 'real essences' (SEP) much closer to recent times. Essences have been the standard ontological primitive for defending realist theories, and to the extent Pearce and others continue to defend strong to moderate forms of realism, the idea that there are real and nominal essences is an important sort of tool that people appeal to sort their mental and physical worlds properly. From the article:

Very simply stated, a real essence, for Locke, is what makes something what it is, and in the case of physical substances, it is the underlying cause of the object’s observable qualities (unless otherwise noted, we shall confine our discussion in this article to the real essences of material substances). A nominal essence, on the other hand, is an abstract idea that we make when we identify similar qualities shared by objects; the nominal essence is the idea of those shared similarities.

In this sense, Pearce's theory relies on a real essence. So far as quantum mechanics is a description of physical phenomena, it suggests that we can reduce consciousness, that (for many) mysterious experience, to something in the physical world (which seems to have an equally mysterious allure to it with uncertainty principles and wave-particle duality). It's nice for those of us who are comfortable with physicalism to have a testable hypothesis that gives some hope in reducing consciousness to physical systems.

Is there any scientific support for the hypothesis? As far as I know, neither Pearce, nor Crick, nor any proponent has provided an iota of confirmation (if one is not a disconfirmatory extremist like Popper, this is good for a tentative conclusion on the matter). Tentatively, it remains a good argument in its various forms, and lives in the heart of strongly realist thinkers.

As someone with strongly anti-realist preferences, I would suggest that using quantum mechanics to impart a real essence to consciousness (which itself isn't even a physical phenomenon) has a certain psychological 'woo-ness' to it. Consciousness is mysterious. Quantum mechanics is mysterious. Therefore, somehow consciousness is intuitively reducible to quantum phenomena. That sort of intuition seems suspect.

I would suggest that to understand consciousness, one is better off with Edelman and Tononi's A Universe of Consciousness. It is, all things being equal, fare more parsimonious a foundation. It simply posits that consciousness is a result of in some way neural reentry. Consciousness is that which is responsible in control theory for system governance. From WP:

Reentry is a neural structuring of the brain, which is characterized by the ongoing bidirectional exchange of signals along reciprocal axonal fibers linking two or more brain areas.1 It is hypothesized to allow for widely distributed groups of neurons to achieve integrated and synchronized firing,2 which is proposed to be a requirement for consciousness...

Thus, what we have is a hypothesis that is built on empirical evidence. We have a hypothesis that explains theintentional stance. And we have a hypothesis that requires no woo (rationalwiki.com).

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