Heat is bad for the soul

If there is one thing that religions absolutely must believe in, it is the existence of the soul, although not all religions give it the same name. Without the belief that there is some entity that is part of us and yet somehow independent of the body and can interact freely with an external deity, much of religious doctrine becomes even more vacuous than it currently is.

But how can the freely acting (Cartesian) soul exist in a world governed by scientific laws? One favored option is to use Heisenberg’s quantum indeterminancy as a mechanism, suggesting that it provides a loophole to escape determinism. This effect is tiny but some religious people who are also scientists (like Ken Miller) pin their hopes on it.

But a new paper by P. G. Clarke titled Neuroscience, quantum indeterminism and the Cartesian soul that appeared in the journal Brain and Cognition (2014 Feb;84(1):109-17) adds to the drubbing that the soul has been getting lately. Here’s the abstract.

Quantum indeterminism is frequently invoked as a solution to the problem of how a disembodied soul might interact with the brain (as Descartes proposed), and is sometimes invoked in theories of libertarian free will even when they do not involve dualistic assumptions. Taking as example the Eccles–Beck model of interaction between self (or soul) and brain at the level of synaptic exocytosis, I here evaluate the plausibility of these approaches. I conclude that Heisenbergian uncertainty is too small to affect synaptic function, and that amplification by chaos or by other means does not provide a solution to this problem. Furthermore, even if Heisenbergian effects did modify brain functioning, the changes would be swamped by those due to thermal noise. Cells and neural circuits have powerful noise-resistance mechanisms, that are adequate protection against thermal noise and must therefore be more than sufficient to buffer against Heisenbergian effects. Other forms of quantum indeterminism must be considered, because these can be much greater than Heisenbergian uncertainty, but these have not so far been shown to play a role in the brain.

In short, he says that in order for neuronal cells to be able to function they have to be able to overcome the disruption of thermal vibrations (that are always present). But these same noise suppression mechanisms will also suppress the much smaller effects of indeterminancy, even if they are amplified by some chaotic mechanism. In order that its signals not be disrupted randomly, the brain has developed a pretty good thermal noise-resistance mechanism.

Every cell in the body is constantly subject to thermal noise – thermally driven molecular movements – and is resistant to its effects. Thermal noise causes significant fluctuations in many cellular events including transcription and translation (“gene expression noise”), ion channel permeability (“channel noise”) and synaptic function (“synaptic noise”). Individual cells and brain function as a whole both have numerous inbuilt noise-resistance mechanisms including mass action, negative feedback and frequency-selective feedback, as I have discussed in detail in a recent review (Clarke, 2012). Thermal noise can be considered random in the sense that it is not biologically controlled or coordinated in any way with cellular function, but is on a sufficiently large scale to be describable by classical (deterministic) physics. This constitutes a fundamental problem for hypotheses of soul-mind interaction based on quantum-scale phenomena, because a neuron (or neural circuit etc.) whose function is resistant to thermal noise should a fortiori be resistant to the much smaller perturbations of quantum phenomena.

The conclusions of this study also raises problems for a free-standing consciousness or free-will in the classical sense. The author seems a little uncomfortable with that and suggests that there may be a way to reconcile those with his work.

The present paper raises problems for attempts to ground notions of a Cartesian soul (or self etc.) or free will on Heisenbergian uncertainty, because the uncertainty is too small in absolute terms and – even more importantly – in relation to the deterministic, but biologically uncontrolled, disruptions due to thermal noise. Moreover neurons and neural circuits have a built-in resistance to the thermal noise, and it seems unlikely that the smaller effects of Heisenbergian uncertainty could overcome the powerful noise-resistance mechanisms.

Even though I raise difficulties for attempts to ground notions of a Cartesian soul (or self) and free will in quantum indeterminacy (Heisenbergian or other), I do not consider that rejection of this particular grounding need undermine the notions of selfhood and free will, because moderate versions of physicalism such as dual aspect theory, and a compatibilist approach to free will provide alternative groundings.

I don’t know that I buy this. You can read more about this study here.


  1. noastronomer says

    I don’t buy it either. Besides if it were true then virtually all vertebrates would have souls. Even dogs.


  2. badgersdaughter says

    My therapist is giving me the hard sell on “What the Bleep Do We Know”. Could not be more timely. 🙂 I only wish I had access to the full paper.

  3. says

    I don’t see how quantum indeterminacy would help with the soul/free will question anyhow; it just moves one from having a deterministic soul to having one that operates based on coin-tosses. That’s actually worse!!!

    To believe one has agency, one implicitly believes that we are deterministic – otherwise, if I am about to do something, I can’t actually believe that the outcome will be what I expect. That completely destroys agency and responsibility! Of course, if we’re determinstic then we’re meat robots! The horror!!

    Simple answer: we’re meat robots that are programmed by evolution to think we have agency. In fact, evolution did such a good job of it that for all intents and purposes, we do. Just like the way evolution programmed us to think we have “3D vision” – well, we do and we don’t, really. But for all intents and purposes, we do.

    The religious are not prepared for what is coming down the pike at them: the conclusive demolition of the idea of the soul. If you think that evolution’s exploding their beloved creation myths triggered an irrational response, wait ’till you see what soullessness does!! There’s going to be tons of epic pseudo-science thrown at the subject and all of it is going to fail because – unfortunately for the religious – it’s all going to be testable. Do you still think prayers work? Cool, tell me: what part of the electromagnetic spectrum do prayers operate in? We will measure for them and find them absent, I predict. If the soul is immaterial and somehow connected to the body, what is the mechanism of that connection? Can’t tell me: it’s not there.

    Of course we feel like we have “souls” – apparently a sense of agency has survival value for meat robots.

    Imagine I write a simple program like Eliza that does basic interaction with a person. Does it have a “soul”? Of course not. But I can program Eliza to respond to the question “Do you have a soul?” with an emphatic “YES! of course I do!” In that sense I have build the illusion of a soul into the program. But it doesn’t mean it has a soul – it just reacts the way something that thinks it has a soul might. Like a human.

  4. Rob Grigjanis says

    Max Tegmark wrote a paper on quantum effects in the brain in 1999. He showed that the timescales of dynamic processes in the brain are much much larger than the associated quantum decoherence timescales (the time in which a superposition of states will ‘collapse’). I thought this put a stake though the heart of ‘quantum consciousness’, but I haven’t exactly kept up with developments.

  5. mnb0 says

    “I don’t know that I buy this.”
    Neuroscience will tell in the future. So quantum indeterminism is out of the picture. It’s a pity, I liked the idea, but that’s science for you (and me).

  6. invivoMark says

    This is exactly what I’ve been saying for years! Good to see it formally worked out, though, even if the author hedges at the end.

  7. sqlrob says

    Wouldn’t this have been put to rest long, long ago with the determination that there’s no hidden variables?

    Nice to see another stake in the “theory”, but is it really needed?

  8. Rob Grigjanis says

    sqlrob @8:

    Wouldn’t this have been put to rest long, long ago with the determination that there’s no hidden variables?

    Do you mean Bell’s theorem? How would that put this to rest?

  9. khms says

    I’m pretty certain we’re not completely deterministic. That means there must be a random number generator somewhere, and thus quantum effects. But note I consider them as a source of randomness, not as a source of meaning.

    As for consciousness, I’m quite happy with my conjecture that that is just a side effect from building a model of the world that includes a model of ourselves. This latter needs to be kept up to date with what we think, and this synchronization is what gives us the sense of self. As such, there’s an illusion involved: what we consider our self is actually just a model of us. (Reminds me a bit of Plato’s cave.) So far, this seems consistent with everything I’ve heard of science results in that area. (Of course, that is not even remotely a proof.)

    Haven’t quite managed to build in “free will”, mainly because I’ve not seen a convincing definition and don’t feel like generating one myself.

    Oh, and I’d expect various kinds of animals to have everything from no model at all to one that’s almost as complete as ours, with the part that models the individuum coming very late in brain evolution. (You need that bit to be able to recognize yourself as like others, and thus reason from your own wants to theirs.)

    Of course, if you wanted to, you could interpret this model as a dualistic soul, but I think this actually stretches those definitions past the breaking point.

  10. Jared A says

    Heat is bad for the soul? That explains why the dead ought to fear a fiery hell.

    I wouldn’t say the author is hedging at the end. The only difference between compatibilism and strong determinism is in how they define categories, so neither philosophy is physical measurements–only what we find to be the most useful way to talk about our findings. I think the author is just acknowledging that fact.

  11. Jared A says

    As for the word “soul”, some strict materialists such as Doug Hofstadter approach it the same way Marcus Ranum talks about 3D vision, in #4, in this case as a token for how a person experience’s their own consciousness–something like what khms is talking about in #10. Even if we accept, as I do, that this experience is itself an illusion, we are still left with the physical manifestations of these experiences somewhere in the purely physical processes of our body. In this sense “soul” is not a binary term, but instead something that is theoretically physically quantifiable, and could, if one wanted, be assigned to certain operations and measured.

    Some may find this flippant, because it is using the word “soul” in a completely different way than dualists do. My reply is that magical thinkers do not have a monopoly on language, and typical usages of the word vary quite a lot, and the type of visceral feelings I am talking about here are standard word usage.

  12. johnhodges says

    Years ago I decided that the issue of “free will vs. determinism” is irrelevant to questions of ethics, and untestable with respect to matters of science. Since then I have tried to avoid wasting time on it. But it comes up every now and then in Freethinker circles, and many people are lured into arguing at length over it.

    Our ordinary practice is to ascribe “free will” to beings which are conscious and intelligent. “Conscious” meaning that they have an internal (“mental”) model of the external world, which they use to anticipate the consequences of different “imagined” courses of action. “Intelligent” meaning that their model is complex and sophisticated, and their imagination likewise, so they can find courses of action that will serve their purposes even in novel situations. “Free will” in such cases means that the great bulk of the IMMEDIATE causes of their actions lie inside their “skin” rather than outside, AND that their actions are not easily or reliably predictable by an outside observer.

    This use of the term “free will” does not require denying the hypothesis of “universal causation”, nor does it depend in any way on whether “causation” is always a single-valued function (i.e. whether the same inputs always produce the same output, or whether instead the output may be any of several values with some statistical probability for each.) In other words, this use of the term “free will” is fully compatible with “determinism”. Beings with “minds” sufficiently sophisticated to have “free will” may operate their “minds” deterministically.

    We assign “moral responsibility” to beings with “free will”, we assign praise and blame, rewards and punishments, to such beings, because that is the easiest (often the only) way we know to intervene in the causal chain. We want them to behave in one way rather than another, so we initiate some causes that we hope will have the effect of modifying their behavior. We hope they will include in their “mental” model that we will respond to their actions with praise/blame, reward/penalty, and that they will therefore “choose” a different course of action. The hypothesis of “universal causation” is irrelevant to this.

    If we gain some ACTUAL KNOWLEDGE of the causal chain affecting their actions, then we may intervene at a different place. For example, if we find that childhood exposure to high levels of lead in the environment leads to neurological damage that results in a lack of ability to control impulses, i.e. their ability to control their own behavior by “rationality” is impaired, then we may seek to reduce crime by banning leaded gasoline, lead-based paint, lead solder in water pipes, and so forth. But this is not the same as “determinism”, considered as a philosophical hypothesis.

  13. sqlrob says

    @Rob Grigjanis, #9

    Do you mean Bell’s theorem? How would that put this to rest?

    You have something completely random with no place for influence. How does agency fit into that?

  14. Rob Grigjanis says

    sqlrob @17: I misunderstood. I thought you meant that quantum effects in the brain had been put to rest. I don’t know anything about agency or consciousness.

Leave a Reply

Your email address will not be published. Required fields are marked *