More on split brains and souls

The immaterial soul, at least as most theists conceive of it, does not exist.  There is an abundance of evidence for this assertion, but I have focused recently (both here and at UD) on observations of split-brain patients in particular.

split head

My argument, in a nutshell, is that split-brain patients have two minds in one skull.  The left hemisphere can believe, know, desire, choose, and act on things separately from the right hemisphere, and vice-versa.  Since theists typically attribute these characteristics to the soul, they can only conclude that there are two souls in each split-brain patient – or more sensibly, that the unified soul was a fiction all along.

UD contributor Vincent Torley has responded to my argument here and here.  In essence, his argument is that most dualists do not believe in the kind of soul that is disproven by the split-brain observations.  He attempts to show that these observations can be reconciled with three kinds of dualism:  the well-known ‘substance dualism’, and two lesser-known kinds that he and Edward Feser espouse, respectively.

(By the way, Vincent, I think you need a better name for your version of dualism.  ‘Thought control dualism’ sounds too sinister. Smile)

I appreciate the care with which Vincent prepares his arguments, the tone in which he presents them, and his willingness to confront the key issues.  Despite our differences, I think his intellectual style and his appreciation of open debate fit in far better at TSZ than they do at UD.

On to the issues.  I think that most dualists are in bigger trouble than Vincent lets on. They believe not only that the soul has the capabilities I mentioned above, but that it can function independently of the body (after death, for example).  That commits them to substance dualism, which is very hard to reconcile with the split-brain observations.

Vincent, for you the soul seems to be inseparable from the body.  For example, you write

…mind and body (or rather, soul and body) are not two things; rather, the human person is an essential unity.

You also write:

It should be noted that memory is viewed as a bodily capacity on both versions of dualism being discussed here. Neither account envisages us as having an “invisible information bank” in an immaterial soul, where we keep our memories. Memories, on both accounts, are stored in the brain.

Those quotes seem to indicate that you, unlike most of your fellow theists, do not think that the soul can function independently of the body.  Is that true?  Don’t you think the soul lives on after death? If so, does it lose its memories?

I’ll have much more to say in the comments, but I think this is an appropriate stopping point until you have given us a better understanding of your exact position.

70 thoughts on “More on split brains and souls

  1. That’s an interesting position. But I’m inclined to see that as all about non-causal supposed functions of the mind. I don’t doubt that theists consider it causal. But it all has to do with causing events in an assumed supernatural realm. If there is no way of telling what, if anything, was caused, I’m not calling that causal.

  2. Neil,

    Actually, no, it doesn’t. It has strong evidence that the brain is involved, but I don’t think dualists deny that.

    Sure, the evidence doesn’t prove that there is no soul, just as the astronomical evidence doesn’t prove that angels aren’t pushing the planets around. But we have no (non-theological) reason to invoke the soul or the angels.

    If the force of gravity seems sufficient to explain planetary orbits, then why posit orbital angels? If the brain seems sufficient to explain the mind, then why posit an immaterial soul?

  3. Neil,

    That’s an interesting position. But I’m inclined to see that as all about non-causal supposed functions of the mind. I don’t doubt that theists consider it causal. But it all has to do with causing events in an assumed supernatural realm. If there is no way of telling what, if anything, was caused, I’m not calling that causal.

    They’re saying something much stronger than that. They claim that the soul initiates our voluntary actions and is morally responsible for them.

    If I plan and carry out a murder, they would say that my soul is fully responsible. When I die, my soul can be judged for that murder. My soul is what caused me to pull the trigger.

  4. If the brain seems sufficient to explain the mind, then why posit an immaterial soul?

    The are aspects of mind that people find unexplained. That’s why there’s an alleged “hard problem.”

  5. Neil,

    The are aspects of mind that people find unexplained.

    Sure, and there are also aspects of physics that people cannot yet explain. Invoking a ‘soul of the gaps’ to explain the former makes no more sense than invoking a ‘god of the gaps’ to explain the latter.

    That’s why there’s an alleged “hard problem.”

    David Chalmers, the inventor of that phrase, thinks the brain is sufficient to explain consciousness. He doesn’t think the immaterial soul makes any sense.

    You don’t have to explain consciousness to see that the soul is bogus, any more than you have to explain OOL to see that ID is bogus.

  6. They claim that the soul initiates our voluntary actions and is morally responsible for them.

    I don’t see moral responsibility as causal in any important sense. I see it as conceptual and cultural.

    For myself, I would ascribe moral responsibility to the person, not to the brain.

  7. Sure, and there are also aspects of physics that people cannot yet explain.

    Physics explains a helluva lot. Neuroscience doesn’t.

  8. For most dualists, ‘morally responsible’ means ‘deserving of reward or punishment’. This is very important to them, because it is the basis on which our eternal fates are decided.

    If the soul is just along for the ride and doesn’t determine what I do, then it makes little sense for God to judge my soul for my actions.

  9. Neil Rickert: I don’t see moral responsibility as causal in any important sense.I see it as conceptual and cultural.

    For myself, I would ascribe moral responsibility to the person, not to the brain.

    Exactly.

  10. For myself, I would ascribe moral responsibility to the person, not to the brain.

    For most dualists, the soul is the person. The body is just a vehicle.

    From the Catholic Encyclopedia:

    The question of the reality of the soul and its distinction from the body is among the most important problems of philosophy, for with it is bound up the doctrine of a future life. Various theories as to the nature of the soul have claimed to be reconcilable with the tenet of immortality, but it is a sure instinct that leads us to suspect every attack on the substantiality or spirituality of the soul as an assault on the belief in existence after death. The soul may be defined as the ultimate internal principle by which we think, feel, and will, and by which our bodies are animated. The term “mind” usually denotes this principle as the subject of our conscious states, while “soul” denotes the source of our vegetative activities as well. That our vital activities proceed from a principle capable of subsisting in itself, is the thesis of the substantiality of the soul: that this principle is not itself composite, extended, corporeal, or essentially and intrinsically dependent on the body, is the doctrine of spirituality. If there be a life after death, clearly the agent or subject of our vital activities must be capable of an existence separate from the body. The belief in an animating principle in some sense distinct from the body is an almost inevitable inference from the observed facts of life. Even uncivilized peoples arrive at the concept of the soul almost without reflection, certainly without any severe mental effort. The mysteries of birth and death, the lapse of conscious life during sleep and in swooning, even the commonest operations of imagination and memory, which abstract a man from his bodily presence even while awake—all such facts invincibly suggest the existence of something besides the visible organism, internal to it, but to a large extent independent of it, and leading a life of its own.

  11. For most dualists, the soul is the person.

    I don’t have a problem with that if it is being used as a metaphor, as something like the way it was used in the the book title “The soul of a new machine.” It’s the theological stuff you quoted that seems to be mostly made up nonsense.

  12. Neil,

    I don’t have a problem with that if it is being used as a metaphor…

    Or even as more than a metaphor. For example, Lizzie and I both believe in material souls.

    As I put it there:

    The brain has pretty much all of the qualities you’d want a soul to have, except perhaps for immortality.

    Neil:

    It’s the theological stuff you quoted that seems to be mostly made up nonsense.

    Indeed, but be aware that most dualists actually believe that stuff.

  13. Even a relatively sophisticated believer like vjtorley will twist himself into knots while trying to hang on to his belief in the soul:

    Hi tragic mishap,

    You raise an excellent question when you ask: “How is it that the resurrected person is the same as the one who died and whose body decayed and burned to ashes?” I agree that a substance dualist can explain this fact readily, but I would ask the substance dualist: “How is it that your soul is tied to only one body, and not several?” It seems that even a disembodied Self has to have physical properties of some sort: in particular, the property of being related to this body and not that one.

    I think a body control dualist could explain the resurrection along these lines: at the highest level of control, my separated rational soul retains a built-in disposition to control a specific human brain (my brain), and to regulate its sensory, motor and vegetative functions. What’s more, I’m inclined to think that this disposition to control must be directed at the actual physical particles that compose my brain at the instant when I die. When I’m resurrected, I have to get most of these back. (The tired old objection from cannibalism strikes me as pretty weak: it would only be a telling one if all of my brain ended up being absorbed by all of someone else’s brain.) When my body is raised to life again, my soul is therefore able to re-inform it.

    I suppose another possibility is that when we die, some “astral” part of our body still survives. That’s highly speculative, but I wouldn’t rule it out.

    A third possibility is that when I die, I get instantly resurrected in Heaven, with a celestial body that’s somehow causally imprinted with the pattern of molecules composing my terrestrial body. A few theologians (e.g. the late Karl Rahner, S.J.) have toyed with the idea of a resurrection at the moment of death, but I agree with former Pope Benedict XVI that this idea seems out of keeping with Scripture, especially 1 Corinthians 15.

    Vincent and tragic mishap are unwilling to consider the obvious: none of the problems above are really problems at all, because the soul does not exist.

    The tapdance is unnecessary. No need to rationalize or to twist oneself into logical knots. Just follow the evidence where it leads. It all makes sense if the soul does not exist.

  14. I’m a long time lurker in this blog and have enjoyed many of the commentators. Since I am fascinated by philosophy of mind, this topic especially caught my interest, in particular Vjtorley’s references to the hylomorphism With limited success, I have tried to puzzle out hylomorphic approach to philosophy of mind as presented in Jaworski’s book on the topic (a book which I found crystal clear on other points).

    I’ve only read Vjtorley’s comments as posted or linked to from this blog, but he does claim that his philosophy is a form of hylomorphism. What I find fascinating is that his version also seems oddly similar to the mind-upload theories advanced by the transhumanists who want to achieve immortality by uploading minds to machines.

    As I understand it, the holymorphic philosophy of mind relies on accepting an Aristotelian approach to causation. In particular, the human soul is a “formal” cause. For complex entities like people, I understand formal cause is meant to refer to function as being causal; for people, it would be the rational aspects of our “souls” which formally cause humans to be different from other animals.

    This idea of formal causation is similar to the functionalist approach to the mind, and in fact Aristotle has been interpreted as the first functionalist. Vjtorley seems particularly to focus on abstract thought and ethical behavior and say these are formally caused by the soul.

    An analogy for formal causes that I find helpful is software: your browser software is causing my post to be displayed on your computer; exactly the same software could (formally) cause it to be displayed on other computers.

    Now most functionalists today are physicalists (but not all, eg Chalmers); they would believe functions are realized in some physical substrate. Similarly, in order for software to cause a physical display, it must be running on some computer. But functionalism is based on the idea that the same functions can be realized on many different physical substrates, just like the same software can run on many different computers, even computers with different system architectures, like Macs and PCs.

    Similarly, Vjtorley seems to believe that your mind needs some substrate to have effect in our world. And just like mind-uploaders believe their minds can realized on immortal hardware, Vjtorley seems to believe that your mind could be preserved and re-realized on something God provides.

    Now I know Vjtorley is not a physicalist: he believes in a form of dualism. Based solely on what I have read, I would guess his rejection of physicalim is driven by his theism which causes him to accept standard arguments against physicalism for the mind such as the explanatory gap (for eg the meaning of thought). I suspect he also does not think compatibilist free will sufficea for true moral responsibility, and hence wants a non-physical basis for free will.

    Nonetheless, his position does seem similar to functionalism and his approach to immortality similar to the transhumanists.

  15. Hi BruceS,

    Welcome to the discussion.

    Since I am fascinated by philosophy of mind, this topic especially caught my interest, in particular Vjtorley’s references to the hylomorphism With limited success, I have tried to puzzle out hylomorphic approach to philosophy of mind as presented in Jaworski’s book on the topic (a book which I found crystal clear on other points).

    The blame may rest more with hylomorphism than with Jaworski. In my opinion, it’s confusing, self-contradictory, and out of step with the modern scientific view of the world.

    I’ve only read Vjtorley’s comments as posted or linked to from this blog, but he does claim that his philosophy is a form of hylomorphism. What I find fascinating is that his version also seems oddly similar to the mind-upload theories advanced by the transhumanists who want to achieve immortality by uploading minds to machines.

    There are some striking similarities, aren’t there? Particularly Vincent’s idea that the soul detaches from the body at death and reattaches to God or to a ‘celestial body’:

    A third possibility is that when I die, I get instantly resurrected in Heaven, with a celestial body that’s somehow causally imprinted with the pattern of molecules composing my terrestrial body.

    Bruce:

    As I understand it, the holymorphic philosophy of mind…

    ‘Holymorphic’ is a nice accidental coinage. And appropriate. 🙂

    …relies on accepting an Aristotelian approach to causation. In particular, the human soul is a “formal” cause. For complex entities like people, I understand formal cause is meant to refer to function as being causal; for people, it would be the rational aspects of our “souls” which formally cause humans to be different from other animals.

    That more or less jibes with my understanding of it, but see below.

    Vjtorley seems particularly to focus on abstract thought and ethical behavior and say these are formally caused by the soul.

    But he thinks that the soul is immaterial and can exist (but not function) separately from the body, which makes him sound more like a substance dualist to me.

    An analogy for formal causes that I find helpful is software: your browser software is causing my post to be displayed on your computer; exactly the same software could (formally) cause it to be displayed on other computers.

    This also seems incompatible with Vincent’s view. He seems to think that a soul is compatible only with a single brain, and even a single set of particular physical particles within that brain (!) :

    It seems that even a disembodied Self has to have physical properties of some sort: in particular, the property of being related to this body and not that one.

    I think a body control dualist could explain the resurrection along these lines: at the highest level of control, my separated rational soul retains a built-in disposition to control a specific human brain (my brain), and to regulate its sensory, motor and vegetative functions. What’s more, I’m inclined to think that this disposition to control must be directed at the actual physical particles that compose my brain at the instant when I die. When I’m resurrected, I have to get most of these back. (The tired old objection from cannibalism strikes me as pretty weak: it would only be a telling one if all of my brain ended up being absorbed by all of someone else’s brain.) When my body is raised to life again, my soul is therefore able to re-inform it.

    (It isn’t just cannibalism that is problematic for that wild view!)

    Similarly, Vjtorley seems to believe that your mind needs some substrate to have effect in our world. And just like mind-uploaders believe their minds can realized on immortal hardware, Vjtorley seems to believe that your mind could be preserved and re-realized on something God provides.

    Yes, though presumably he would insist, contra the uploaders, that you cannot capture the essence of a person even with a comprehensive brain scan. The immaterial soul is inaccessible that way.

    Now I know Vjtorley is not a physicalist: he believes in a form of dualism. Based solely on what I have read, I would guess his rejection of physicalim is driven by his theism…

    Undoubtedly. If you read his last three posts at UD (and his comments), you can see that he is much softer on dualist/theist arguments than he is on monist/physicalists arguments. He even seems a bit sheepish about the double standard.

    On the one hand, intelligent people can be good at rationalizing. On the other hand, Vincent seems to be honest. If he’s honest with himself about the (lack of) evidence for his theist/dualist views, he must be experiencing a great deal of cognitive dissonance. I feel for the guy.

    I suspect he also does not think compatibilist free will sufficea for true moral responsibility, and hence wants a non-physical basis for free will.

    That’s right. He’s a defender of libertarian free will.

  16. Thanks for your thoughts — a few brief comments.

    Jaworski’s book is a clearly-written, well-structured review of all the positions in philosophy of mind, but he is a professor at Fordham and is writing from a Catholic-Aristotelian perspective. When he reviews the pros and cons of a position, It does seem that his book gives the last counter-argument to the non-naturalists. But I still recommend the book for an introduction, with that caveat.

    Jaworski’s treatment of formal causes in hylomorphism is different from vjtorley’s and harder for a naturalist to understand. He believes formal causes are a new class of causes, that physical actions can have both physical and formal causes without the formal causes being realized or depending on some other way on the physical environment. He would agree with you that this is not in line with current scientific philosophy, although he does accept science as explaining the physical world. His glossary definition of the scientific revolution says that the rejection of Aristotelian science was correct but rejecting his philosophy of causes was a mistake leading to intractable problems like the mind-body program. It is fascinating how someone who is clearly very intelligent and very familiar with naturalists approaches to philosophy of mind can hold such a position.

    My reading of vjtorley’s thought control dualism, on the other hand, is that formal causes seem to rely on using underlying physical mechanisms to act in the world, eg the use of brain for physical memory, relating moral actions to the left brain, and his third possibility on resurrection (with God operating an Star Trek transporter, it seems). That view of formal causes seems much closer to functionalism and realization.

    Thanks for the links to his other posts at UD. He does seem to have well thought out positions, but I personally find it too tedious to sort through the less logical posts on UD to find them. I admire the perseverance of people who take the time to read all of UD postings, but I personally don’t have the stomach for it.

    Is there an easy way to do a point-by-point response like yours in WordPress, or do I have to manually insert the HTML?

  17. BruceS,

    My reading of vjtorley’s thought control dualism, on the other hand, is that formal causes seem to rely on using underlying physical mechanisms to act in the world, eg the use of brain for physical memory, relating moral actions to the left brain, and his third possibility on resurrection (with God operating an Star Trek transporter, it seems). That view of formal causes seems much closer to functionalism and realization.

    Except that Vincent is adamant that thought is an immaterial process:

    In any case, I would argue that the immateriality of thought is pretty obvious, given our ability to entertain purely abstract concepts (such as true, false, real, prime etc.) which cannot be cashed out in material terms.

    Thanks for the links to his other posts at UD. He does seem to have well thought out positions…

    He’s a smart guy, and he does put a lot of thought into his posts. The problem, in my opinion, is that most of the effort goes toward propping up his theistic beliefs, and relatively little toward trying to figure out what makes the most sense. If he ever gets to the point where he resolves to pursue the truth, come what may, I think we’ll see his faith come crashing down rather spectacularly.

    Is there an easy way to do a point-by-point response like yours in WordPress, or do I have to manually insert the HTML?

    I do it using HTML. 99% of what I need is covered by the ‘blockquote’, ‘a’, ‘i’ and ‘b’ tags.

  18. Thanks for html advice.

    I understand vjtorley thinks thought is immaterial. The same applies to functionalism before the realization substrate is specified. I believe that is how it gets multiple realizability if I understand it correctly.

    keiths:
    I do it using HTML. 99% of what I need is covered by the ‘blockquote’, ‘a’, ‘i’ and ‘b’ tags.

  19. BruceS,

    I understand vjtorley thinks thought is immaterial. The same applies to functionalism before the realization substrate is specified. I believe that is how it gets multiple realizability if I understand it correctly.

    The difference is that under functionalism, the physical substrate is sufficient to implement the entire function. For Vincent, no physical substrate ever suffices. An extra immaterial something is required in order to achieve the full function.

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