Is interactionism consistent with our best physics?

homerstriplebypass7.png

Earlier today I came across a post about the mind-body problem (among other things) by someone writing under the pseudonym The Thinker. The Thinker argues that our theories of fundamental physics (which he refers to collectively as “Core Theory”) are so precise and have proven so successful in so many tests that we ought to accept those theories as true, and if they are true then interactionist substance dualism is false. (Interactionist substance dualism, by the way, is the view that the mind or soul is composed of a non-physical substance that interacts with physical substance.)

The argument can be stated as follows:

  1. Interactionism entails that the mind causes physical phenomena at the levels Core Theory is concerned with.
  2. If interactionism is true, there should be anomalous physical phenomena that Core Theory does not account for.
  3. Core Theory accurately accounts for all physical phenomena at the most fundamental levels.
  4. Interactionism is false.

This might seem at first like a compelling argument against interactionism, but I think there’s a big problem with it: there’s no reason to think that the physical end of mind-body interaction should appear in any way anomalous. All tests of Core Theory have been conducted in a universe with minds in it; if mind is not matter but it affects the material world, then the physical effects of non-physical minds are already part of the data from which Core Theory was derived and which Core Theory so precisely and reliably explains. So the second premise is false, and without it the argument is invalid. The success of Core Theory certainly constrains interactionists’ options as they try to develop a more fine-grained account of the relation between the mental and the physical, but it does not rule out interactionism altogether.

Advertisements

9 thoughts on “Is interactionism consistent with our best physics?

  1. Thanks for responding to my post.

    there’s no reason to think that the physical end of mind-body interaction should appear in any way anomalous. All tests of Core Theory have been conducted in a universe with minds in it; if mind is not matter but it affects the material world, then the physical effects of non-physical minds are already part of the data from which Core Theory was derived and which Core Theory so precisely and reliably explains.

    Your objection relies on a huge “if”: mind is not matter but it affects the material world. In other words it assumes dualism’s ontology. So in other words your argument is: assuming dualism is true, non-dualism is false. That’s hardly a refutation. The data from Core Theory was not tested on brain matter but rather inanimate matter. So even if we assume dualism for the sake of argument, the soul/mind would only be affecting the atoms that make up people, not particles in an accelerator. So this argument fails this way as well.

    Your objection would have to agree that the soul is already accounted for in the 4 fundamental forces. But there is no extra force working on humans. It’s the same 4 forces. Let me ask you this:

    1. If we have a soul, and that soul gives us free will, wouldn’t it have to be the case that this soul has a force that has a causal effect on the physical matter that makes up your body that overrides the existing natural forces known in physics? Yes or no?
    2. If yes, that soul-force is either accounted for in the laws of physics or it is not, true or false?
    3. If it is accounted for, where in the equations of physics is this found?
    4. If it isn’t, then where is the evidence of a 5th force overriding the natural forces governing your body? This should have been discovered since this 5th force must be affecting the atoms in your body every second you exercise free will and make a choice.
    5. If this force is not part of the existing forces, wouldn’t it be injecting new energy into the universe violating the law of the conservation of energy? Yes or no? If no, why not?

    Like

  2. But I don’t actually claim that dualism is true. My objection is about what things would be like *if* [interactionist] dualism is true.

    If I understand correctly, you claim that if dualism is true, then Core Theory would be violated whenever mind-body interaction occurs; because we have overwhelming reason to think Core Theory is never violated, we should conclude that dualism is false.

    My objection grants that Core Theory is never violated; instead, I’m challenging the claim that if dualism is true, then Core Theory violations would occur. Core Theory is based upon observation of the world; if mind-body interaction is a feature of the world, then Core Theory already accounts for the physical effects of mind-body interaction in its description of the world, so mind-body interaction will produce no physical anomalies or discrepancies with the theory.

    The second part of your response, as I understand it, is that the success of Core Theory has only been tested against inanimate matter, so physical effects of mind-body interaction wouldn’t be included in the data from which Core Theory is derived and therefore these physical effects should appear anomalous if they exist.

    I see a couple of problems with this. There’s no evidence of novel fundamental physics at work in animate matter. Assuming, for the sake of argument, that there is some kind of novel fundamental physics at work in animate matter, this would contradict the claim that Core Theory exhaustively describes fundamental physics. And if Core Theory does not exhaustively describe fundamental physics, then mind-body interaction in violation of Core Theory cannot be ruled out. Now it seems much more likely to me that the fundamental physics at work in animate matter is just the same as the fundamental physics at work in inanimate matter. If there were any anomalies that suggest novel physics, we should have noticed by now. Because we haven’t noticed any anomalies, and we should have noticed them if there were any to notice, we should conclude that the fundamental physics at work in animate matter is probably just the same as the physics at work in inanimate matter. Our observations of animate matter, then, should be taken to support Core Theory. This is sufficient to make such observations part of the data against which Core Theory has been tested.

    I think you’re assuming that if mind-body interaction occurs, it must take the form of special physics that applies only in the vicinity of a brain or something like it. But this is not a necessary implication of interactionist dualism. Without compromising their dualistic credentials, interactionists can just as easily claim, for example, that mind-body interaction takes the form of bog standard physics that applies in the vicinity of the entire cosmos.

    Like

    • I’m challenging the claim that if dualism is true, then Core Theory violations would occur. Core Theory is based upon observation of the world; if mind-body interaction is a feature of the world, then Core Theory already accounts for the physical effects of mind-body interaction in its description of the world, so mind-body interaction will produce no physical anomalies or discrepancies with the theory.

      I know but you’re incorrect. If mind-body dualism were true there would be a special force that only affects human bodies and not anything else, like (presumably) animals, plants, or inanimate matter. That would mean that those things are covered by Core Theory which is no room for a soul force, but us humans are an exception to the laws of physics. That would require that we break the laws of physics simply by existing, but that of course is not the case since we do sometimes test on people (eg. as in neuroscience). So your option if ruled out.

      There’s no evidence of novel fundamental physics at work in animate matter. Assuming, for the sake of argument, that there is some kind of novel fundamental physics at work in animate matter, this would contradict the claim that Core Theory exhaustively describes fundamental physics. And if Core Theory does not exhaustively describe fundamental physics, then mind-body interaction in violation of Core Theory cannot be ruled out.

      There isn’t any novel fundamental physics at work in inanimate matter and not in humans: the same laws of physics and forces apply to all things made of atoms. We are no exception.

      I think you’re assuming that if mind-body interaction occurs, it must take the form of special physics that applies only in the vicinity of a brain or something like it. But this is not a necessary implication of interactionist dualism. Without compromising their dualistic credentials, interactionists can just as easily claim, for example, that mind-body interaction takes the form of bog standard physics that applies in the vicinity of the entire cosmos.

      I’m taking both views into account and saying neither leaves room for the possibility of soul force-stuff existing. If interactionists want to claim that soul affects all of nature around us they will have to answer my questions above to make any sense. Which is the soul force in the equations of physics? As I wrote, all the known forces have ruled out any kind of force that can travel from humans (or anything else) to other things, and this view would force one to think the soul force is contained within the known forces in Core Theory. So that’s simply impossible. It just isn’t a rational position.

      Anyway thanks for your time.

      Like

      • “If mind-body dualism were true there would be a special force that only affects human bodies and not anything else, like (presumably) animals, plants, or inanimate matter.”

        I’m not sure why you think this is a necessary feature of dualism. Do you have an argument for it? I’m also puzzled why you are now so sure that Core Theory applies to the human brain; previously, you claimed “Core Theory was not tested on brain matter but rather inanimate matter” and cited this as the reason why mind-body interaction cannot be among the data from which Core Theory is derived. Just to be clear, I don’t object to the idea that the physical laws at work in the brain are the same as the physical laws at work everywhere else — it makes no difference to my argument one way or another. But if you agree that observation of the brain tends to confirm Core Theory, then I’m not sure why you would reject the conditional claim that if mind-body interaction occurs, Core Theory already already describes the physical end of the interaction. No special “soul force” is possible, but no special force is needed.

        “If interactionists want to claim that soul affects all of nature around us they will have to answer my questions above to make any sense. Which is the soul force in the equations of physics?”

        I don’t see why this would be necessary. The claim that mental substance co-determines the nature of the physical world seems perfectly intelligible without specifying the degree to which that nature is determined by mental substance. As far as I can see, we could only speculate on the degree of mental substance’s contribution, and nothing of any importance turns on it. With that caveat, I’ll have a crack at your questions.

        “1. If we have a soul, and that soul gives us free will, wouldn’t it have to be the case that this soul has a force that has a causal effect on the physical matter that makes up your body that overrides the existing natural forces known in physics? Yes or no?”

        I assume you’re talking about free will in the libertarian sense. I’m a compatibilist, but I suppose the kind of interactionism I’m defending here (which isn’t actually my view, but I’ll refer to it that way for simplicity’s sake) doesn’t rule out the possibility of libertarian free will. I’m inclined to say that free willings undetermined by any prior cause could occur, but these would determine rather than override physical laws.

        “2. If yes, that soul-force is either accounted for in the laws of physics or it is not, true or false?”

        On my view, the physical effects of mental substance interacting with the physical world are accounted for in the laws of physics.

        “3. If it is accounted for, where in the equations of physics is this found?”

        Nowhere in particular. The laws of physics describe the most fundamental order of the physical world that can be given a precisely ordered description; the determining ground of this order is a metaphysical question, not a scientific question.

        “4. If it isn’t, then where is the evidence of a 5th force overriding the natural forces governing your body? This should have been discovered since this 5th force must be affecting the atoms in your body every second you exercise free will and make a choice.”

        N/A

        5. If this force is not part of the existing forces, wouldn’t it be injecting new energy into the universe violating the law of the conservation of energy? Yes or no? If no, why not?

        N/A

        Like

  3. Pingback: Is physicalism consistent with our best physics? | Popcorn Machine

  4. I’m not sure why you think this is a necessary feature of dualism. Do you have an argument for it?

    “Dualism” here is mind/body duality. There is a body, and there is a mind or soul that comprises humans. That mind/soul is like a spirit that can causally effect the body and the body can causally effect it (interactionaism). If the mind/soul causally effects the body, it has to do so through some kind of force. There’s no way it can effect physical matter without one. That leaves us with only two possible options:

    (1) This soul force is accounted for within the known laws of physics
    (2) This soul force is not accounted for within the known laws of physics and would be a new unknown force. Furthermore, this soul force would have to either effect the human body only or effect more than the human body.

    This are our only possible choices. I’ve shown why either option fails. If you think I haven’t, please show me where my argument fails.

    I’m also puzzled why you are now so sure that Core Theory applies to the human brain; previously, you claimed “Core Theory was not tested on brain matter but rather inanimate matter” and cited this as the reason why mind-body interaction cannot be among the data from which Core Theory is derived.

    On humans we’re mostly talking about higher levels of science than physics. We usually study humans at the levels of biochemistry, biology, neuroscience, psychology, and sociology. And all those levels of science of are (and have to be) compatible with the fundamental laws of physics. And when we do neuroscientific tests they are always compatible with the laws of the conservation of energy, momentum, etc.

    But if you agree that observation of the brain tends to confirm Core Theory, then I’m not sure why you would reject the conditional claim that if mind-body interaction occurs, Core Theory already already describes the physical end of the interaction. No special “soul force” is possible, but no special force is needed.

    Because I’ve already argued that the same forces act on everything: humans and nature. And I’ve already argued that there are no forces that humans can have that can effect anything without physical touching it (there are no psychic forces). So if this soul force is one of the 4 forces, there’s nothing unique about humans, and humans cannot do anything. What would this soul force do that isn’t done by the natural 4 forces? How can we tell its existence from non-existence? You’ve literally made it worthless and completely superfluous. So the burden on you is to explain it: Show the soul force’s hypothetical possibility, or show the soul’s ability to do what we normally think souls do.

    The claim that mental substance co-determines the nature of the physical world seems perfectly intelligible without specifying the degree to which that nature is determined by mental substance.

    No it isn’t because physical substances completely account for the physical world. You’re literally just supposing something extra on zero evidence in order to defend this view in a way that isn’t coherent.

    On my view, the physical effects of mental substance interacting with the physical world are accounted for in the laws of physics.

    Where are they accounted for? What makes you think this is the case, or could possibly be the case?

    Nowhere in particular. The laws of physics describe the most fundamental order of the physical world that can be given a precisely ordered description; the determining ground of this order is a metaphysical question, not a scientific question.

    Do you really think that’s a sufficient answer? You’re defending the view that there is mental stuff, a soul that interacts with the physical body that is accounted for in the laws of physics, but then you say it’s “nowhere in particular.” I can’t take this seriously.

    Like

    • “Dualism” here is mind/body duality. There is a body, and there is a mind or soul that comprises humans. That mind/soul is like a spirit that can causally effect the body and the body can causally effect it (interactionaism).”

      I think you’re confusing “body” in the sense of a human body with “body” in the sense of material substance. Interactionists are committed to the idea that mental substance causally interacts with material substance; they are not committed to the idea that mental substance causally affects only human bodies or body parts. Because interactionists are not committed to the idea that mental substance causally affects only human bodies or body parts, they are not committed to the idea that there is a special force that acts only on human bodies or body parts. I think your argument successfully rules out the latter idea, but it doesn’t rule out interactionism as such.

      “Because I’ve already argued that the same forces act on everything: humans and nature. And I’ve already argued that there are no forces that humans can have that can effect anything without physical touching it (there are no psychic forces). So if this soul force is one of the 4 forces, there’s nothing unique about humans, and humans cannot do anything. What would this soul force do that isn’t done by the natural 4 forces?”

      What I’ve been arguing is that the “soul force” — that is, the force by which mental substance affects physical substance — could be partly constitutive of the natural forces. A universe where mind-body interaction did not occur would be appear to be governed by different laws — gravity might be a little (or a lot) stronger, for example, or a little (or a lot) weaker. Or, if you believe in emergent phenomena, perhaps certain physical structures (such as those found in the brain) would tend to cause a weakening or strengthening of some force or other, if the physical effects of mental substance didn’t come in to bring things back to normal.

      The fundamental laws of physics are either brute facts, or they are true in virtue of some further facts about nature which are not discoverable by means of physics. In the form of dualism I’ve been discussing, the fundamental laws of physics are true in virtue of facts about physical substance *and* the physical effects of mental substance. So I agree that the same forces act on everything. But that doesn’t rule out interactionism.

      “No it isn’t because physical substances completely account for the physical world. You’re literally just supposing something extra on zero evidence in order to defend this view in a way that isn’t coherent.”

      I can agree as far as this: it is possible that facts about physical substances are what makes Core Theory true. However, the claim that facts about physical substances are what make Core Theory true is not a scientific claim; it’s a metaphysical claim. And it’s not necessarily true. It is possible that facts about physical and mental substances are what makes Core Theory true, or facts about mental substances alone. These are all perfectly intelligible claims, and perhaps all of them have merit. I don’t think any of them can be dismissed altogether.

      Some “evidence” (if you want to call it that) for mental substance is that there are mental phenomena, mental substance could explain why there are mental phenomena, and there is some reason to think that mental phenomena cannot be explained by physical substance alone. I’m not claiming that these reasons are dispositive, only that they should discourage us from dismissing interactionism out of hand.

      “You’re defending the view that there is mental stuff, a soul that interacts with the physical body that is accounted for in the laws of physics, but then you say it’s ‘nowhere in particular.’”

      I don’t see how you could possibly pin down which parameters of a fundamental physical theory are determined by mental substance, or the degree to which they are so determined. In any case the answers to these questions have no implications for the content of a completed fundamental physics. I don’t think the answers would have any interesting metaphysical implications either.

      Like

      • Interactionists are committed to the idea that mental substance causally interacts with material substance; they are not committed to the idea that mental substance causally affects only human bodies or body parts. Because interactionists are not committed to the idea that mental substance causally affects only human bodies or body parts, they are not committed to the idea that there is a special force that acts only on human bodies or body parts. I think your argument successfully rules out the latter idea, but it doesn’t rule out interactionism as such.

        I’ve already told you that I can take either view: mind only causes body or mind cause everything, and Core Theory rules all of them all out.

        What I’ve been arguing is that the “soul force” — that is, the force by which mental substance affects physical substance — could be partly constitutive of the natural forces. A universe where mind-body interaction did not occur would be appear to be governed by different laws — gravity might be a little (or a lot) stronger, for example, or a little (or a lot) weaker. Or, if you believe in emergent phenomena, perhaps certain physical structures (such as those found in the brain) would tend to cause a weakening or strengthening of some force or other, if the physical effects of mental substance didn’t come in to bring things back to normal.

        I’ve already shown you how such a view makes no sense and cannot be justified. If it’s accounted for in the known forces, what forces are they and how would they be any different is there was no soul force? Only electromagnetism and gravity can have any far reaching effects, and none of them can account for anything that the “soul force” is typically claimed to do. None of the known laws give us anything that can plausibly justify a “soul force.” I do believe in emergent phenomena, but nothing about weak emergentism allows for strengthening any of the forces that could plausibly make any sense of a soul force.

        The fundamental laws of physics are either brute facts, or they are true in virtue of some further facts about nature which are not discoverable by means of physics. In the form of dualism I’ve been discussing, the fundamental laws of physics are true in virtue of facts about physical substance *and* the physical effects of mental substance. So I agree that the same forces act on everything. But that doesn’t rule out interactionism.

        False dichotomy. The laws of physics can certainly be the way they are in virtue of some discoverable physical theory. That’s what the theory of everything is supposed to do. The fundamental laws of physics are incompatible with any model of a mental substance that has anything to effect on a physical substance. You’d be saying that the 4 forces are the mental substance, and it effects everything, including rocks, which of course makes no sense, and you’re completely incapable of showing how it’s even possible to distinguish this mental substance from it not existing.

        However, the claim that facts about physical substances are what make Core Theory true is not a scientific claim; it’s a metaphysical claim. And it’s not necessarily true. It is possible that facts about physical and mental substances are what makes Core Theory true, or facts about mental substances alone. These are all perfectly intelligible claims, and perhaps all of them have merit. I don’t think any of them can be dismissed altogether.

        It is absolutely a scientific claim proven with decades of scientific tests. Claiming physical and mental substances are what makes Core Theory true is a metaphysical claim. And a bad one at that. (I don’t define the metaphysical as only something that cannot in principle be scientifically verifiable, by the way.) You don’t even have a coherent possible explanation to make your case. We have plenty of evidence from outside physics, like neuroscience, showing that consciousness is a product of brains. Not rocks, not grass, not water.

        and there is some reason to think that mental phenomena cannot be explained by physical substance alone.

        No there isn’t. All the current evidence suggests that consciousness is most likely an epiphenomenon that’s an emergent property of particular complex physical processes.

        I don’t see how you could possibly pin down which parameters of a fundamental physical theory are determined by mental substance, or the degree to which they are so determined. In any case the answers to these questions have no implications for the content of a completed fundamental physics. I don’t think the answers would have any interesting metaphysical implications either.

        That makes this view you’re defending unverifiable and unfalsifiable. That’s why it’s not something to be taken seriously. We’ve ruled out a soul, as much as that might displease you. Purely physical forces and matter can completely explain you. There is no need for a mental substance.

        Like

  5. The laws of physics can certainly be the way they are in virtue of some discoverable physical theory. That’s what the theory of everything is supposed to do.

    That seems like a normative claim, not a scientific claim. Many scientists and philosophers reject the idea that a final theory can or should aspire to reveal metaphysical truths (i.e. fundamental truths about what there is), and instead believe that a theory of everything should only be expected to provide an especially accurate and comprehensive predictive model. I agree that a final theory of physics could be true in virtue of truths about the physical, though.

    The fundamental laws of physics are incompatible with any model of a mental substance that has anything to effect on a physical substance. You’d be saying that the 4 forces are the mental substance, and it effects everything, including rocks, which of course makes no sense, and you’re completely incapable of showing how it’s even possible to distinguish this mental substance from it not existing.

    Why would it make no sense for mental substance to affect rocks? Remember, from the dualist perspective, all matter is dumb matter. Rocky matter on the ground isn’t fundamentally different from goopy matter inside the skull. Certainly there seems to be a special relationship between what happens to the goopy matter in our heads and what happens in our minds. But it doesn’t follow that the relationship between goopy matter and the mind is the only relationship that holds between mind and matter.

    We have plenty of evidence from outside physics, like neuroscience, showing that consciousness is a product of brains.

    There are certainly very strong correlations between what happens in brains and what happens in minds. What those observed correlations allow us to infer about the nature of consciousness and the role of the brain is an open question.

    All the current evidence suggests that consciousness is most likely an epiphenomenon that’s an emergent property of particular complex physical processes.

    I’m not sure where you get that from. By definition, there can be no positive physical evidence of a mental epiphenomenon. Do you mean there’s negative evidence? I’m thinking the argument would be along these lines:

    1. Consciousness is either epiphenomenal or there will be physical evidence of consciousness exercising causal influence that cannot be wholly explained by the underlying neurological machinery.
    2. There is no physical evidence of consciousness exercising any causal influence that cannot be wholly explained by the underlying neurological machinery.
    3. Therefore consciousness is epiphenomenal.

    
It’s a valid argument, but the truth of the first premise is precisely what’s at issue in this whole disagreement. I deny that there would necessarily be any physical evidence of mind-body interaction if interactionist dualism (or, as I discuss in another post, strong emergentism) is true. There would be no physical evidence of mind-body interaction if the the fundamental laws of physics as we understand them are themselves determined by mind interacting with body.

    That makes this view you’re defending unverifiable and unfalsifiable. That’s why it’s not something to be taken seriously.

    That’s not a problem in this case, though. The point of my argument is that it’s possible for mind-body interaction to occur undetectably. That’s why interactionist dualism isn’t ruled out by the body of evidence produced in support of Core Theory. If you agree that the view I’m defending is a form of interactionism, and you think it can’t be falsified, you can’t hold on to your argument that interactionism must be false because Core Theory is true.

    So now you seem to be saying that interactionism can be rejected because it’s unfalsifiable, not because Core Theory has falsified it. That claim needs a very different argument. Verifiability and falsifiability are qualities that good scientific theories are supposed to have. But I’m not proposing a scientific theory, so I don’t see why the view I’m proposing can be dismissed just because it doesn’t conform to the standards of a scientific theory.

    Purely physical forces and matter can completely explain you. There is no need for a mental substance.

    That’s speculation. At this time, there is no physical explanation for consciousness. That doesn’t mean there won’t ever be a purely physical explanation for consciousness (although I think it’s highly unlikely, barring a radical rethinking of what counts as “physical” ), but it does mean we can’t know whether mental substance is needed to explain consciousness. Because mental substance would explain consciousness, and it might be needed to explain consciousness, we have some reason to think that mental substance exists. Whether we should actually believe that mental substance exists is a further question. But it’s not true that there’s nothing for mental substance to do.

    Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s