The Soul’s Burden of Proof

Recently, I have taken to listening to podcasts of college courses during my downtime–commuting, perambulating, staring into space–and I have had great fun making my way through Open Yale Courses and similar. I am now about halfway through Shelly Kagan’s Philosophy[2] course on “Death” (the course actually focuses on the existence of souls, the nature of persistence of identity and meaning of immortality, and the ethics of suicide). Kagan spends the first about 10 sessions presenting an apologia (sort of) for the physicalist[5] view that the soul is “[something the body can do]”[1] rather than an immaterial entity intimately associated with the body (what is called the dualist view). I say sort of, because Kagan argues strongly that he has no more responsibility to disprove souls than he does to disprove fire-breathing[3] dragons. And in that lack of responsibility stands a matter of huge logical, philosophical, religious, and social significance. (PS, a simple summary of what follows is available just before the footnotes)

By his assertion that the soul bears the burden of proof (it is a figment of imagination unless proved to be real), Kagan bluntly but powerfully sidesteps the vexing problem of consciousness and manages to perpetuate his worldview in an ultimately rather non-reflective way. Kagan chooses as analogies fire-breathing dragons and unicorns. He argues that he can be confident that they do not exist as long as he is able to refute or reject any evidence that they do exist. In the event of an evidential vacuum (ie nothing can be proved one way or the other), there are no dragons or unicorns. By placing the soul beside ancient traditions now almost universally rejected as fanciful, Kagan looks forward to a day when the intellectual tenor of society will reject the soul on similar terms (it does not yet, a point that the tenor of his undergraduate proselytism underscores[4]). To him this prophecy and aspiration is sufficient to reject (for himself) and to disprove (to others, whom he rather forcefully calls into allegiance to the advancing worldview that supports this limited view of the soul) the existence of the soul.

The problem is that the burden of proof here is all in how you pose the question. If we assume the physicalist view as reasonable, then a view that deviates will bear the burden of proof, while if we assume some sort of dualism is reasonable, then physicalism bears the burden of proof. The stakes seem reasonably high to me, since in my experience most philosophical arguments are able to provide rather limited durable, conclusive evidence of fundamentals like the existence of the soul. Since a tie is almost guaranteed, it seems to me that it matters a great deal how we interpret a tie.

Speaking in what I understand to be philosophical terms, though, if we conceive the physicalist mind (an epiphenomenon of the brain’s neural circuitry that dualists call the soul) as a construct attempting to explain the phenomenon of consciousness, then I think we have an argument with a burden of proof. When even Kagan admits that there is no currently compelling physicalist account of consciousness, I am hard-pressed to see how an account that rejects the crux of self-awareness (the mind’s sense that it is in fact distinct from the body, a point clearly made in Descartes’ classic thought problem[6]) can be taken as true without evidence. The closest anyone is coming to a physicalist accounting of consciousness is with complex systems analysis, and it’s not even clear what it means to be able to model an emergent phenomenon similar to consciousness as an account of consciousness. As religious theorist Jonathan Z. Smith famously reminds us “Map Is Not Territory,” and as Einstein (and any other scientist worth her rigorous salt) would have us know models are not the reality they seek to model, but are extracts from it. So accounting for a complex mental entity that a) is the one doing the accounting, and b) conceives of itself as non-physical, by saying that “[someone will figure it out eventually, I just know it]” seems to me to bear the burden of proof. Quod Errant Demonstrandum.[7]

SIMPLIFIED SUMMARY: Kagan says the soul is guilty (of being a religious fable) until proven innocent, so if there’s no evidence for or against it, then there isn’t a soul. I say that you can as easily say that the “mind” (the belief that the soul is just something the body does while it’s alive) is guilty (of being a scientistic fable) until proven innocent. So that’s what (my soul and) I say.

[1]I’m paraphrasing.
[2] I know little if any actual philosophy, and my comments should be interpreted as only those of an outsider who likes to read and interact with ideas.
[3] He actually argues that there are no dragons but clearly by that does not intend Komodo Dragons but rather the fire-breathers that have bated the breath of more than one nervous man-child obsessed with Tolkein’s hairy-footed worlds.
[4] Kagan very openly and repeatedly confesses his aim to persuade his audience that there is in fact no soul. It quickly starts to wear thin, but I haven’t been an undergraduate for some time, and may therefore not represent his target audience.
[5] Physicalist pretty much means what outsiders mean when they say “materialist” or “secular” or “atheist.” Basically, the physicalist viewpoint is that there is nothing beyond physical existence.
[6] Descartes argued that because we can easily imagine our mind as a disembodied entity that proves mind and body are separable. I agree with Kagan that this is not an adequate philosophical proof of the soul’s existence, but I do think it’s a powerful reminder and demonstration that the mind conceives of itself as separate from the body, a point he does not engage in these lectures.
[7] Again, I am not a philosopher or a mathematician, hence the pun. Sue me.


  1. I’m with you Sam. It is an rather obvious debate trick that Kagan is trying to use by setting up the playing field entirely in his favor (though I like to use that same trick whenever possible as well). Your reversal is of course the appropriate response to that old trick.

    Thanks for the tip about those online courses. I will have to try those out.

  2. Why, when we tamper with parts of the brain, do people’s very essences change drastically. What could be called the essence of a person, the mind, the soul, whatever, seems to have a distinct relationship with the brain, regardless of our thinking of it as distinct (or something that could be possibly distinct).

  3. #2 that’s a great question. To be honest, the physicalists and the dualists won’t necessarily give you very different answers here–the relationships between mind and brain (or soul and brain) are complex but obviously present.
    Were I a better philosopher, I might wonder rather explicitly about how the soul:brain interface affects and informs our doctrine of mortal probation and the complex paradoxes of embodiment.

  4. Great post Sam! Actually, I don’t completely disagree with Kagen (and thanks for the tip on these lectures. I listen to the Teaching Company a lot, but hadn’t t heard of these.). The reason is, is that I think any explanation of consciousness requires that the burden of proof is picked up by the claimant. This is the default position of science, i.e., that since the only thing we have access to is the physical world, scientifically we have to assume an explanation lies in that realm, that or give up. However, consciousness has some problems in that we only have access to one, our own. This presents a problem in that there is no, and will not be any, objective test of its presence. We can only take people’s claim that they are having such experiences and note neural correlations with that claim (or other evidences that we suppose reflect consciousness in others when we see it in ourselves). In some ways subjectivity is outside of science. This is the hard problem. But there are lots of explanations people have put forth, epiphenomenalism (as you mentioned), functionalism, ensoulment, panpsychism, Higher Order Thought theories, or that it is an illusion, as claimed by Dennett (although I wonder whose illusion seems to bet the question). In all these though, I do think the burden of proof lies with the claimant. It seems like Kagen as not risen to the challenge, however, and claims of what it is not also carries with it making necessary proofs especially when it is a widely accepted belief. To argue that it is like claims of their being fire-breathing dragons may be right, but the argument often will seem silly to people who have seen the dragons and felt the heat of their fire.

  5. I don’t think the physicalist notion of the mind/soul is a strong argument at all, actually. It suffers from several serious difficulties, and at least one seemingly insurmountable difficulty. The serious, but not deadly, difficulties include the distinctiveness of mental and and physical properties, the implications for morality, responsibility, and punishment, and several others.

    But, the real problem, which been admitted to even by many atheist philosophers, is that it is self-refuting. If the physicalist view of The Mind is correct, then all beliefs and notions are literally just physical states, and therefore determined by previous physical states coupled with the laws of physics. It is basic to the laws of physical motions and properties that they are all the result of sufficient physical causes. If it is the case that Mind is only physical, then it is by definition the only way that it can possibly be! In other words, Kagen only believes in physicalism because there’s no other belief that he can possibly have, given previous physical states and the laws of physics. Therefore, his opinions and conclusions are essentially meaningless.

    It’s possible that physicalism is actually true, of course — but it’s self-refuting to say that you “know” or “believe” that it’s true.

    Just discovered this blog – great post.

  6. BWR, I think they argue that the physicalist mind may be able to encounter physical laws and make useful inferences from observations related to physical laws as fancy machines. But you’re right that there is a necessary tentativeness to the rigorously physicalist view. (I reject the physicalist view; I like to do so with careful attention to its merits as well as its failings.)

  7. smb: I understand where you’re coming from, but I think the problem is simpler than that. If the contents of your Mind (your beliefs, convictions, conclusions based on evidence, etc) are actually causally settled by the laws of chemistry and physics, then they aren’t to be taken seriously as rational or compelling. Rationality requires an “agent” view of mind. In other words, if a person’s beliefs and other mental outputs are wholly caused by physical factors, then it’s impossible to say that one “ought” to accept them.

    So, in that case, it has been determined by the previous states of the physical world that Kagen will believe whatever he believes. He can’t help it anymore than a rock can help falling off a cliff.

    Because physicalism denies the possibility of rationality (by affirming determinism), it is self-refuting to “believe” in it.

    That’s my point, and I’ll be quite now because I’m still getting the hang of the culture of this blog and I don’t want to talk too much.


  8. I don’t think physicality affirms determinism at all. Physical science tell us the world is not deterministic. So that particular argument against physicality fails, in my opinion.

    I’m rather of the “refined matter” school, with Joseph Smith. What is happening with consciousness is definitely beyond our current understanding, but I’m sure it’s beyond all understanding forever.

    What’s clear to me, though, is that people tend to do a lot of arm waving, describing lower biochemical based processes, and then saying, (poof), that leads to consciousness. They don’t seem to hear the “poof” in their own arguments.

  9. I’m NOT sure it’s beyond all understanding forever, sheesh!

  10. apropos determinism in 7, Many physicalists start to sound like Fritjof Capra as they spout silly nonsense about the implications of quantum probability. I think they argue that the metaphysical “agent” you describe isn’t strictly required and that something like quantum probability liberates them from determinism. for what it’s worth Schroedinger’s cat is an extrapolating thought experiment rather than an actual requirement of quantum theory.

  11. If we assume the physicalist view as reasonable, then a view that deviates will bear the burden of proof, while if we assume some sort of dualism is reasonable, then physicalism bears the burden of proof.

    The existence of the physical is a priori knowledge. We have no such knowledge of the metaphysical. It is therefore more reasonable to take a “physicalist” approach to the question.

  12. Tatiana,
    What’s clear to me, though, is that people tend to do a lot of arm waving, describing lower biochemical based processes, and then saying, (poof), that leads to consciousness. They don’t seem to hear the “poof” in their own arguments.

    I don’t hear the “poof” either. What’s so special about consciousness that it requires a “poof” to exist as a physical phenomenon of the brain?

  13. Sam, as a non-philosopher, I advance my ideas with humble trepidation.

    As I understand your description of physicalism vs. dualism, I stake my tent in the physicalism camp. While I agree that the mind is a fable until proven innocent, we have already corraled the physicalist’s unicorn. We have the brain and are quickly unraveling the nature of its functions. We already know that it controls behavior, emotion, belief, sensory experiences, memory, etc. We can map these on to territory of the brain and show through PET scans how different experiences affect the brain and how the brains of different populations react differently to similar experiences.

    Yes, there is still a “black box” aspect to the brain, but we are getting closer. We don’t know how all the circuitry works, but we know where it is found.

    In my opinion, the circuitry creates the mind and the sense of self. In some ways this is deterministic because our genes and pre-natal hormone exposure create our neural structures, but it is also clear that lived experience serves to rewire the strucutres.

    As for the soul, the best philosophical advice I received was in freshman physical science at BYU. Okham’s Razor has been an excellent guiding principle for cutting away extraneous constructs and simplifying explanations. Yes, it is possible that the soul also inhabits the structures of the mind and body, but while we lack proof that it is there we are better served by building our beliefs on empirical footing.

    Adding a soul to the mix adds some benefit to the conversation, but also adds myriad conflicts and inconsistencies (i.e. religion, other existences, miracles) that aren’t easily resolved through philosophy or science.

  14. Randall said it better than I could, but I agree. Sure, physicality still has something to prove, but what if suddenly it doesn’t? Religionists have a long history of backtracking when ideas that weren’t really doctrine anyway suddenly become pure fantasy.

  15. As someone who actually works in biomedical research, I have a healthy appreciation for the cultural role of what some Christian apologists call scientism in our inferences about the probability of successful decoding of the meaning of mind vis-a-vis body. At some point it just starts to sound like boosterism to me, which is primarily my point. Being adamant that we are going “to figure it out” strikes me as a matter of pseudo-religious faith. I am very open to being flexible in sorting out tricky problems like this, but my point is that putting all our eggs in the physicalist basket at this point is scientistic rather than scientific.

  16. I don’t really get it.

    There’s this idea “We’re going to figure it out.”

    and then there’s the opposite idea, “We don’t need to figure it out. It’s a soul.”

    The latter sounds like it takes much more for granted than the former.

  17. Sam, what advances in neuro-science do you believe are yet required to prove that brain=mind?

  18. No one is doubting the close interactions between brain and mind or brain and soul. The biggest problem as I see it is that these sorts of complex systems tend to only be reasonably modeled with relatively black-box approaches, and the traditional scientific approach of hammering away reductionistically at “centers” of the brain, many of them prettified versions of the voyeuristic Ripley’s Believe it or Not neurosurgical stimulation anecdotes (“look, I just gave her an out-of-body experience, there couldn’t possibly be a soul”), have poor face validity as meaningful explanations. Current techniques are of merely heuristic application or are so distant from an adequate model of the brain as mind as to be little more than journalistic projectiles in the war over physicalism.

    My main protest is really against the massive scientistic overextrapolation from frankly very limited studies. We don’t even know what the brain models of even 20yrs from now will look like, so why the boosterish certainty that they will demonstrate the necessity of the physicalist view?

    As for 16, I understand the fundamental question as one of accounting for human consciousness/self-awareness which appears in its nature to represent an intersection between a brain and something else by saying either: nah, there can’t be anything else because even though we don’t have a compelling account for it being unitary, someday we certainly will because otherwise this sense that it is dual that religious people like to exploit will win, vs., “fair enough, it does seem dual, so why don’t we work on characterizing as much as we can how everything works but without seeing behind ever pebble new evidence for physicalism”

    Sorry that these run-on–am running a pretty high sleep deficit right now.

  19. Sam,

    So, if I understand you, what you’re saying is that since we still lack a solid understanding of how brains generate minds, we might just as well abandon everything we’ve learned from science over the past 1,000 years or so and instead look to metaphysics for an explanation?

  20. Re 18

    It’s not so much saying, “Nah, there can’t be anything else.”

    but more of a matter of, “Things have seemed to work out in a unitary way every time before. Our research and evidence suggests it is unitary now; we just don’t know how. It’s certainly possible that there could be some lurking variable that we don’t know about, but why assume more when things work out just fine assuming less?”

    Kinda going off what kuri says in 19, why are we abandoning this large body of evidence for a rather exceptionalist idea that has little going for it?

    I mean, it just seems to me that when we have the case that whatever the very essence of a person can be drastically changed, wrecked, repaired, rearranged, made or remade merely by changing neurology or brain chemistry, then the question is not if brains generate minds, but how. So, it seems like it is not 50/50 physicalism vs. dualism (and I’m not even sure if these terms are precise enough, but then again, I’m not a philosopher). It seems that dualism still has quite a bit of distance to make up.

  21. Randall (#17), unless we begin by assuming what we aim to prove, why would we believe it possible to prove that brain = mind? To deny that equation is not to deny that there is no mind with brain. It is to deny that mind-talk can be reduced to brain-talk.

    Much of the discussion of mind and brain assumes that the equation “brain = mind” makes sense. But why should we assume that when what we are talking about when we talk about brains is very different than what we are talking about when we are talking about when we talk about minds. “I intend to have grapefruit for breakfast” may be–probably is–correlated directly with some set of neural firings and responses that we could in principle describe accurately. Nevertheless, the happening of that set of neural events is not the experience of having the intention to eat grapefruit for breakfast.

    Saying that I am going to eat a combination of flour, water, sugar, and leaven and including the relative portions of each, is not the same as saying that I am going to eat cake. Flour, water, sugar, leaven, etc. does not = cake. Similarly, to say “desk” is not to speak of particular kinds of atoms arranged in molecular patterns and vibrating within a vast open space even though we would not deny that there is no desk without the atomic-molecular properties of the desk.

    Science is an incredibly useful way of parsing the world, but it is not the ultimate way. (I don’t believe there is an ultimate parsing, but that’s another story.) Not every way of parsing the world can be reduced to science’s way of doing so. And one need not deny the scientific parsing in order to assert some other one, nor vice-versa.

  22. I can agree with what you say, Jim F (21), but I wouldn’t necessarily suggest that science is all about saying, “Oh, cake must only be flour, water, sugar, leaven, etc.,” The experience of “mmmmm good stuff” need not necessarily be unscientific.

    There is a distinction between pointing out that experience of “mmmm good stuff” is different than “flour, water, sugar, leaven, etc.,” and suggesting that this experience exists independently of the brain.

  23. Sam (#18) “I understand the fundamental question as one of accounting for human consciousness/self-awareness which appears in its nature to represent an intersection between a brain and something else.”

    Isn’t the “something else” the environment in which we live, and the other organisms that inhabit the environment?

  24. Andrew, I don’t understand what you are saying. Can you fill it out a bit? If you are saying that there is often an aesthetic element to science, then I agree. But, of course, I have not suggested that the experience of “good stuff” exists independent of the brain.

    My point is that the question is not an ontological question, though it seems to be. It is a question about what language does and how it works, combined with the claim that the world is irreducibly complex so no one language about it will suffice as the ultimate, all-encompassing language for speaking about things. The assumption that mind = brain–and in most cases the assumption that it does not–is an assumption that there is some ultimate language about the world and a disagreement over what that language is. That is what I am arguing against.

  25. Jim, it just seems that sometimes, people accuse science of being something that reduces the amazing qualities of life simply by discovering how they work (or seeking to discover how they work in a certain framework). I was more making a statement to everyone and bouncing an idea off of your post.

    I guess I can see what you mean about the way language is used though.

  26. For the record, Kagan is not one who believes we will ever understand the mind, nor will he accept the idea we will ever figure it all out. He argues we need the concept of mind kept separate from brain. I guess for me that’s what makes his assertion about soul so perplexing.

  27. argh, should read ….ever figure it all out through study of the brain….

  28. Doh– I just realized I am thinking of Jerome Kagan, you are speaking of Shelly Kagan. What I would love to see would be a Kagan vs Kagan debate.

  29. First, an apology for being more brusque and strident than I would like. Don’t have enough time to flesh this out in a mellower way.

    #19–that comment is reasonably representative of the school of thought called scientism, which I reject.
    #23–that’s trivially true and not to the point I was making–the mode of interaction with the environment appears to represent an interaction between brain and “mind” or “soul”.
    #20–ditto on scientism. you’re relying on a strawman soul theory that seems to posit no interaction between brain and mind. no one is arguing that the mind/soul isn’t affected by brain (though to be honest when you actually read the science, it’s far from clear that our culturally potent image of brains malfunctioning by token of “chemical imbalances” means very much at all–it certainly means much less than our adoption of it into common language and worldview would seem to imply).

    as for the disparaging (mis)use of the term metaphysics, it misses the point–we are attempting to describe something that in every current interpretive mode remains metaphysical (there is not yet a credible exclusively physical account of mind). The question is whether the burden of proof should be with an explanation that involves a metaphysical component or one with absolutely no metaphysical components at all. This is far from settled philosophically, intellectually, or scientifically (it has only been solved scientistically to date); I am arguing for the burden on the explanation that lacks any metaphysics whatsoever in attempting to explain a manifestly metaphysical entity.

  30. as for the disparaging (mis)use of the term metaphysics,

    Hey, I can use “metaphysics” if you can use “scientism.” ;)

    it misses the point–we are attempting to describe something that in every current interpretive mode remains metaphysical (there is not yet a credible exclusively physical account of mind).

    Is there a credible metaphysical account of anything? That’s a serious question, BTW. We constantly confirm the utility of science on a daily basis. (The medium in which we’re discussing this should be proof enough of that.) But what objective knowledge have we obtained through metaphysics? What evidence is there of its utility? Why should any reasonable person accept the idea that it is a useful tool for obtaining knowledge?

  31. Stupid HTML tags. Only anything should be italicized in that last paragraph.

  32. kuri,
    The point is that Gould’s distinction between science and religion (or philosophy) is accurate. Science is excellent at asking and answering “how.” However, it is horrible at answering “why.” Science can easily demonstrate what areas of the brain light up when we think about different things or experience different emotions, but it doesn’t do a great job of explaining the whys of the thoughts or the whys of the emotions. This isn’t to say that we shouldn’t look into the hows or use science in attempting to understand the whys. But rather we should accept sciences limited ability to provide generally satisfactory answers to the why. In other words, even if we could currently identify the bio-chemical processes that occur in the brain to give us the impression that we have a self and a soul, that wouldn’t demonstrate that the soul is an illusion or that it isn’t God-given. Even if you could create an artificial circumstance that causes one to lose this sense of soul, it wouldn’t demonstrate that the soul is an illusion or that it isn’t God-given. To the honest believer, they would alter their belief to accommodate this and move on.

    For that matter, since metaphysics tend to come down to subjective explanations, there are loads of metaphysical explanations that are credible; just not for everyone.

  33. John,
    Somewhat contrary to what I may have implied in this thread, I don’t entirely discount “metaphysics” as a valid source of subjective information. But it seems to me that Sam is addressing a “how” question (or technically a “what” question, i.e., “What is mind?”) not a “why” question (i.e., “Why is mind?”). And he also seems to be claiming that a “why” method (“metaphysics”) is just as valid as a “how” method (science) for answering this “how” question. That’s where I disagree.

  34. Re 32:

    I have to agree with Kuri (33)…it seems that while people would like to pay credence to the “different magisteria” idea, separating a how from a why…in practice, everyone wants to talk about *how* and *what* instead of why.

    I am also not a fan of scientistic thinking…and I have fought it many times when people have suggested that we have some kind of “purpose” to fulfill biological needs in just passing our genes or some other mechanical purpose and that’s that. But you see, that example is a place where people are taking the ‘what’ and ‘how’ of science and improperly putting it as why.

    This discussion doesn’t seem much like that.

    For example, the way you phrase things seems more fit to “what” or “how” terms. What is the mind? It is “a soul” or it is “God-given.” It is “more than a mere product of the brain.” These are distinct “whats” and “hows” that try to go on scientific (not scientistic) turf. This is problematic because this distinct answer to “what” leads to different consequences. I think that the religious cannot rest easy with the scientific “what” because it doesn’t patch up well with an afterlife or many other concepts…I mean, let’s say we asked, “Why do humans have such a mind? Why do we have such feelings?” And then we said the answer of this why question is God. Well, without a change to the what answer…if we still use a scientific (not scientistic) answer, “What is the mind? It is a product of the brain” then no matter why we have this mind that is the product of this brain, we don’t have much other than faith to go on to suggest that after the brain dies, our minds will persist.

  35. But, fundamentally, calling the mind a “soul” is roughly the same as calling it “what happens when this area of the brain lights up.” The how or what doesn’t differ a bit; those terms indicate whys. Sam’s argument, it seems to me, is that Kagan is being scientistic by insisting that those who believe in a soul have a burden of proof at all. Kagan isn’t playing fair and Kagan likely knows it. As I understand it, Sam is saying that one could just as easily do the same from the other direction. So arguing over burden of proof proves nothing; it only ingratiates you with the choir.

  36. mgarelick says:

    I’m into about the 12th session of Kagan’s class, and I’m going to focus on one particular point in one of the lectures on physicalism/dualism. The large subject was whether there is good reason to believe in an immaterial soul (dualism, roughly speaking), and the framework was “inference to the best explanation” — basically, that we would have reason to believe in a soul if it provided an explanation for something that could not be explained on physicalism. The specific topic was consciousness. Kagan described the “big problem” (although I don’t think he called it by that name), and I think he not only did a good job of showing why it is a big problem but also stated frankly that there was no good answer on physicalism. But he rejected consciousness as a sufficient reason to accept dualism. Why? Because dualism also has no satisfactory explanation for consciousness.

    A student asked whether he was merely implementing a bias for physicalism; i.e., couldn’t he just as reasonably reject physicalism because it provided no satisfactory explanation for consciousness. Good question, he said. The answer is that dualism requires that we add something to the picture. There is no argument on the table about the existence of bodies, so the physical side of dualism is given. How are we to decide whether to add something to the picture? Back to the beginning of the discussion: inference to the best explanation. Is there anything that can be explained by an immaterial soul, and otherwise could not be explained?

    I think Kagan is on solid ground. He set out the framework of the inquiry and applied it reasonably. A tie is a loss for the challenger.

    If you think you have good reason to believe in a soul, that’s fine. If you want to convince me to believe in a soul, you need to convince me that there is a good reason — not just to question my existing beliefs, but to accept yours.

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