Mind and Cosmos

WStandard.v18-27.Mar25.Cover_ Back in the Dark Ages, a person with heretical theological beliefs would occasionally be burned at the stake. Nowadays, when a more scientific worldview has triumphed and everyone knows that God doesn’t exist, the tables have turned, and any slight deviation from scientific/naturalist/atheist/Darwinian doctrine will have you literally tied to a pole and set on fire. Fair is fair.

Or, at least, people will write book reviews and blog posts that disagree with you. But I think we all agree that’s just as bad, right?

The ominous image shown here was the cover of an issue of The Weekly Standard back in March, illustrating a piece by Andrew Ferguson. The poor heretic being burned is Thomas Nagel, philosopher at NYU and the author of Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False. The crowd of sinister hooded pyrophiliacs includes–well, me, actually, as well as the other participants in our Moving Naturalism Forward workshop. As Ferguson points out, there is irrefutable video evidence that we accused people like poor Tom Nagel of being “neither cute nor clever.” Many might perceive an important distinction between saying someone is not clever and roasting them alive, but potayto, potahto, I guess.

It’s true that Nagel’s book has occasioned quite a bit of discussion, much of it negative. For a sampling from various viewpoints, see Elliott Sober, Brian Leiter and Michael Weisberg, Michael Chorost, H. Allen Orr, Malcolm Nicholson, and Jerry Coyne. The reason for all the fuss is, of course, that the materialist Neo-Darwinist conception of nature is almost certainly true, so it’s worth pushing back against a respected philosopher who says otherwise.

(By the end of this overly long post I will suggest that Nagel, despite being generally way off track, nevertheless has a bit of a point that many people seem to be passing over. Much like the Insane Clown Posse in a different context.)

This week Nagel took to the NYT to publish a brief summary of his major arguments, for those who haven’t read the book. There are basically two points. The first is that the phenomenon of consciousness cannot be explained by the workings of inanimate matter alone; you need more than the laws of physics.

The physical sciences can describe organisms like ourselves as parts of the objective spatio-temporal order – our structure and behavior in space and time – but they cannot describe the subjective experiences of such organisms or how the world appears to their different particular points of view. There can be a purely physical description of the neurophysiological processes that give rise to an experience, and also of the physical behavior that is typically associated with it, but such a description, however complete, will leave out the subjective essence of the experience – how it is from the point of view of its subject — without which it would not be a conscious experience at all.

This is an old idea, and Nagel’s sympathy for it can be traced back to his influential paper “What Is It Like To Be a Bat?”. The claim is that there is something inherently subjective about the experience of consciousness, something that cannot be shared with other conscious beings nor described by physics. (Even if you know every physical fact about bats, you still don’t know what it’s like to be a bat.) This position has been developed in subtle ways by philosophers like David Chalmers. Nagel actually doesn’t spend too much time providing support for this stance, as he wants to take it as understood and move on.

The second and more important point is that, because of the first point, a purely physical view of the world is incomplete, and we have to add something to it, and that addition is going to end up being pretty dramatic. Nagel believes that an adequate explanatory framework must not merely be compatible with life and consciousness, but actually entail that these dramatic and central features of reality are “to be expected” — that there is a “propensity” in nature for them to arise. Since he doesn’t see such a propensity anywhere in physics, he thinks the conventional view by itself fails as an explanation.

[S]ince the long process of biological evolution is responsible for the existence of conscious organisms, and since a purely physical process cannot explain their existence, it follows that biological evolution must be more than just a physical process, and the theory of evolution, if it is to explain the existence of conscious life, must become more than just a physical theory.

In particular, he claims that the standard scientific picture must be augmented by a non-physical notion of teleology — directedness toward a purpose. And not just an emergent notion of purpose that might be compatible with physicalism. Nagel is thinking of something fundamental: “teleology requires that successor states . . . have a significantly higher probability than is entailed by the laws of physics alone.”

So Nagel rejects “scientific naturalism” or “reductionism” or “materialism” or “physicalism,” but also rejects theism. He wants to find a middle ground, which he labels “antireductionism”; this need not necessarily entail a rejection of naturalism, and indeed he at one point uses the phrase “teleological naturalism” in a sympathetic way. He doesn’t seem to think we need to look beyond the natural world, but we do need to look beyond the laws of physics.

In the responses to his book, much has been made of the fact that a lot of Nagel’s reasoning is not very good. He repeatedly invokes “common sense,” and puts forward the Argument From Personal Incredulity in an especially unapologetic manner:

[F]or a long time I have found the materialist account of how we and our fellow organisms came to exist hard to believe, including the standard version of how the evolutionary process works… This is just the opinion of a layman who reads widely in the literature that explains contemporary science to the nonspecialist.

Given that he is admittedly not an expert in the scientific fields he is willing to label as “almost certainly false,” there must be a deep-seated reason underlying Nagel’s conviction. That reason seems to be the enormous importance he places on the “intelligibility” of nature. This is something like the Principle of Sufficient Reason (which he mentions). Nagel believes that the specific laws of nature, or even the fact that there are such laws at all, and that we can understand them, are all things that require an explanation. They cannot simply be (as others among us are happy to accept). And the only way he can see that happening is if “mind” and its appearance in the universe are taken as fundamental features of reality, not simply byproducts of physical evolution.

Try as I might, I cannot quite appreciate the appeal of this program. I could imagine that, after much effort were expended experimentally and theoretically, we might ultimately come to believe that the best explanatory framework for the appearance of consciousness in the universe involves positing mind as a separate category. What I don’t understand is the a priori-sounding argument that this would necessarily be a better explanation. If Nagel can demand an explanation for why the world is intelligible, why can’t I demand an explanation for why mind is a separate category, or why the universe has teleological tendencies? I don’t see the distinction; in either case, one must take certain facts about reality as simply given. My preference would be to minimize the weight given to our intuitive ideas about what form a proper explanation should take, and keep looking for the simplest and most powerful model that fits the data.

(This issue is related to a point that gets raised when I mention that we understand the laws of physics underlying everyday life. Inevitably someone says that we don’t really understand gravity, man. They’re not claiming that general relativity fails to provide a model that successfully fits all the known data; they’re claiming that the existence of such a model doesn’t count as “understanding.” People who deny that physics can ever account for consciousness have a similar idea; even if we had a complete theory that accounted for every possible observable action of purportedly conscious creatures, they would not be satisfied that this qualified as “understanding” or “explanation.” For me, that’s just a misunderstanding of what kinds of explanations we can legitimately hope for.)

However! Let me stake out a brave contrarian position among my anti-Nagelian friends by pointing out something important that I think he gets right. Namely, point number two above (scientific materialism is incomplete and needs to be augmented by something apart from the physical) actually does follow, under plausible assumptions, from point number one (consciousness cannot be explained in purely physical terms). Nagel is correct to have appreciated that once you say “consciousness isn’t merely physical” (or indeed once you’ve accepted the kind of strong antireductionism that is relatively popular in contemporary philosophy), the ramifications for fundamental science are profound indeed.

Except, of course, I want to use this to reach the opposite conclusion: the idea that we need something like a non-material teleological principle, a “propensity” in nature for things to develop a certain way, is so dramatically at odds with what we’ve learned about the world in the time since Galileo that it gives us good reason to deny that consciousness can’t be explained in physical terms.

Imagine what it would entail to truly believe that consciousness is not accounted for by physics. It would entail, among other things, that the behavior of ordinary matter would occasionally deviate from that expected on the basis of physics alone, even in circumstances where consciousness was not involved in any obvious way. Several billion years ago there weren’t conscious creatures here on Earth. It was just atoms and particles, bumping into each other in accordance with the rules of physics and chemistry. Except, if mind is not physical, at some point they swerved away from those laws, since remaining in accordance with them would never have created consciousness. In effect, the particles understood that sticking to their physically prescribed behaviors would never accomplish the universe’s grand plan of producing conscious life. Teleology is as good a word for that as any.

So, at what point does this deviation from purely physical behavior kick in, exactly? It’s the immortal soul vs. the Dirac equation problem–if you want to claim that what happens in our brain isn’t simply following the laws of physics, you have the duty to explain in exactly what way the electrons in our atoms fail to obey their equations of motion. Is energy conserved in your universe? Is momentum? Is quantum evolution unitary, information-preserving, reversible? Can the teleological effects on quantum field observables be encapsulated in an effective Hamiltonian?

This is not a proof that consciousness must be physical (as some folks will insist on misconstruing it), just an observation of the absolutely enormous magnitude of what the alternative implies. Physics makes unambiguous (although sometimes probabilistic) statements about what will happen in the future based on what conditions are now. You can’t simply say that physics is “incomplete,” because on their own terms physical theories are not incomplete (within their domain of applicability). Either matter obeys the laws of physics, or physics is wrong. And if you want us to take seriously the possibility that it’s wrong, you better have at least some tentative ideas about what would be a better theory.

Of course, Nagel has no such theory, which he cheerfully admits. That’s for the scientists to come up with! He’s just a philosopher, he says.

Which is why, at the end, his position isn’t very interesting. (Because he doesn’t have anything like a compelling alternative theory, not because he’s a philosopher.) He advocates overthrowing things that are precisely defined, extremely robust, and impressively well-tested (the known laws of physics, natural selection) on the basis of ideas that are rather vague and much less well-supported (a conviction that consciousness can’t be explained physically, a demand for intelligibility, moral realism). If someone puts forward even a rough sketch of how a new teleological view of reality might actually work, including how it affects the known laws of physics, that might be very interesting. I don’t think the prospects are very bright.

This entry was posted in Philosophy. Bookmark the permalink.

95 Responses to Mind and Cosmos

  1. Tom Stolze says:

    What can I say? Shades of Richard Dawkins, Lawrence Krauss, Chris Hitchens et al, Sean Carroll is relatively new to me; or should I say I am new to Sean Carroll. Though a lot of his stuff is way over my head, at the age of 82, still autodidactic, I continue to learn more and more. I’m happy to be here with this sort of thing to read, unfortunately in the state of NC where public education continues to be stifled, encouraging un-patrolled “homeschooling” or no education at all, discouraging open mindedness. Teachers like Sean Carroll are refreshing. I call your attention to andrewtobias.com, 8/14, Quote of the Day: “The purpose of education is to replace an empty mind with an open one.” [Malcolm Forbes] Andy is a close friend of mine. Try is column, as well : andrewtobias.com

  2. max says:

    Imagine what it would entail to truly believe that consciousness is not accounted for by physics. It would entail, among other things, that the behavior of ordinary matter would occasionally deviate from that expected on the basis of physics alone…

    This doesn’t really seem to follow. Subjective experience could require some non-physical explanation (or, at least, some extension to the laws of physics or to physical ontology) without requiring any change in our description of the objective physical world. Then consciousness and subjective experience would (or could) be exactly correlated with physical states, but just not in any way describable by our current low-level understanding of physics. What’s wrong with this view?

  3. Sean Carroll says:

    max– How do you have “some extension to the laws of physics” but not “any change in our description of the objective physical world”? Do particles obey the laws of physics without exception, or not?

  4. Higguns says:

    I absolutely hate the consciousness arguments made by people like Nagel. He doesn’t want there to be an explanation. He wants the world to remain mystical. Is the reason because it makes life easier to understand because there is something that can’t be understood (equals nothing to understand)? I think so. I think this is a person justifying their ignorance of a subject. Or like so many religious followers, the idea that there is nothing special about nature brings about a stunning and suddenly tangible realization that we really are weak and powerless compared to nature; an idea that they overcome by believing in an all powerful entity that controls the universe and has our back against anything nature can throw at us. It seems like an egotistical defense mechanism to reject that we are not special in any way at all, that we are only more complex.

    Proof of the physical description of consciousness being accurate is in the fact that we (an overwhelming majority anyway) can all identify a specific color or a specific sound or a specific smell, without any corrupted influence from other people.

    It’s the same load of crap that you hear from an idiot boss who doesn’t really know what he’s doing: I’m an ideas man, I’m a big picture guy. You just make it work, never mind if it’s impossible. Who needs physics to build a bridge when you’ve got a big IDEA? I don’t mean to disrespect, but Mr. Nagel sounds an awful lot like a typical troll; pick something apart without any facts supporting why it should be picked apart and then get upset when people don’t believe what you believe.

  5. Guy says:

    Clear and reasonable as usual. Thanks professor! I can’t wait for your discussion with Bill Craig in February.

  6. Doc C says:

    Consciousness may be explainable by adequate physics, but current physics only points to a full understanding. Subjectibve experience, while emerging from physical interactions, may have a teleological character not deterministically reducible. I think One of the participants in the Moving Naturalism Forward conference, Terence Deacon, has done a good job of outlining this line of thinking in “Incomplete Nature”.

    Additionally, I think Robert Mangabeira Unger, in unpublished manuscripts available on his website (http://www.law.harvard.edu/faculty/unger/index.php) “The Religion of the Future”, and “The Self Awakened”, does a fantastic job of outlining a practical moral and philosophical application that a complete understanding of human nature beyond the obvious physical aspects of our existence could use to improve human civilization.

  7. max says:

    The argument would be that the laws of physics are currently incomplete: they perfectly describe (low-energy) objective phenomena, but they fail to describe subjective experience. Particles would still obey the laws of physics without exception, but something else would be needed to explain consciousness. Whether you call that something else an extension to the laws of physics or a non-physical law would just be a matter of semantics and categorization.

    Of course, there are many ways to argue against such a theory. My point is only that having consciousness be indescribable by basic physics as we currently understand it does not necessarily imply that the basic physics is wrong in its description of objective physical systems.

  8. Will says:

    Wow what a great post, so many little bits I’ll be using again. I never really thought about how many people tacitly believe that non-physical consciousness and a sensible physical world can coexist, but its probably a reasonably large number, and I think that notion needs to be attacked head on.

    Then consciousness and subjective experience would (or could) be exactly correlated with physical states, but just not in any way describable by our current low-level understanding of physics. What’s wrong with this view?

    I’ve heard this before, and I don’t think its a totally trivial argument but it does kind of fall apart if you think hard about it. Like Sean said, what would this really mean if it were true? Is there some way in which you could tell a universe with this kind of epiphenomenal consciousness apart from one where the mind is purely physical? If not, then there really is nothing wrong with that belief, because it doesn’t really contain any information; its not even wrong. I really liked some of Eliezer Yudkowsky’s writing on this topic – there’s some in-depth articles, but I’m a fan of the movie version

  9. Ron Murphy says:

    I’ve only just realised I don’t know what it feels like to be a computer, or the internet of computers. OMG! What might be the implications? Oh, no change? Okay. Carry on.

  10. Sean Carroll says:

    As Will says, anything you want to “add” to the laws of physics either changes the behavior of particles, or it doesn’t. If it doesn’t, it has absolutely no perceivable affect on anything, including the atoms in your brain and the sounds that you speak and the words that you type, and can safely be ignored. If it does, show me how it changes the Dirac equation.

  11. Higguns says:

    Max,

    The problem for me is the inability for anyone to describe what consciousness is in clear and definitive terms. Any definition that I’ve been given has itself been a matter of interpretation. It seems like a concept without a meaning which is backed up by definitions which do not give a meaning.

    Saying something like:

    “Whether you call that something else an extension to the laws of physics or a non-physical law would just be a matter of semantics and categorization.”

    is a BIG problem in understanding the central argument here. It is definitely not a matter of semantics and categorization. It is further fluff without a meaning which can’t be proven or discredited. Like Will says above, it’s not even wrong because it has no meaning. If it has no meaning or effect on the physics of our universe, then it doesn’t exist and it has no effect on us since we are a result of the physics of our universe.

    I would suggest naming a conscious experience that illustrates how consciousness can’t be described by physics. I don’t think it’s possible for you (or anyone, not picking on you) to accomplish that suggestion.

  12. edw says:

    Dr. Carroll,

    Thanks for another thoughtful post.

    You at least suggest we ought not to proceed from “intuitive ideas about what form a proper explanation should take” but rather proceed by “looking for the simplest and most powerful model that fits the data.” It seems to me that in doing the latter, one is implicitly doing the former. That is, one has made up one’s mind about what form a proper explanation should take: it should be a simple and powerful model that fits the data.

    Of course, there’s good reason to have this idea of what a proper explanation should look like. But at the same time, figuring out what counts as simple, powerful, and fitting – indeed figuring out what counts as something’s meeting any criterion or standard – seems as intuitively or conventionally or creatively determined as anything.

    So I’m wondering if you would expand a little on why you think “looking for the simplest and most powerful model that fits the data” is not just our acting on “intuitive ideas about what form a proper explanation should take.”

    Thanks.

  13. Sean Carroll says:

    edw– I would distinguish between “the type of theory we look for” and “types of theories we insist must exist.” We look for simple and powerful theories because they are most useful to us. (If there are multiple theories that fit the data equally well, why wouldn’t we provisionally accept the simplest and most powerful one?) That is very different from saying that we have any reason to expect that simple/powerful theories actually will fit the data. The fact that they do is nice, but not necessary. If we didn’t find any simple way to describe the world, we would take what we could get.

  14. Jim Cross says:

    I did a write up on Nagel about 6 months ago.

    http://broadspeculations.com/2013/02/24/nagels-mind-and-cosmos/

    An excerpt:

    We can illustrate the Nagel’s argument with a simple example. I am looking out my window now seeing sunlight hitting a pine tree in my back yard. The pine tree has grayish-brown rough bark with gnarls and cracks. As sunlight brightens one side there is a shadow on the other side of tree. Behind the tree are more trees and blue sky. All of what I am seeing is a product of light waves reaching my eyes and being assembled in my brain into colors and images. My perception is totally dependent on my eyes and the neurons of my brain. Yet my perception is not the same as the actions of my eyes and brain. Clearly there is something left over beyond the sensual and neural mechanism that underlie my perception, something beyond chemicals, neurons, and electrical activity. That something is my experience of the gray bark, the sunlit side of the tree, and the blue sky. Even if reductionism could explain in detail everything at the physical level that makes perception happen, it cannot explain the why of my subjective experience. Why is that subjective experience necessary in our universe?

    Perception is perhaps the smallest unit of our mental life. The argument could be extended to every aspect of our mental life: ideas, beliefs, abstract thought, values, planning, reasoning, and even fantasy and dreaming. Even our understanding of order, the basis of science, would be included. Order and design imply mind. Order is in the mind of the beholder and there would be no order without a mind to behold it. No matter how deeply the we associate mental activity with neurons and chemistry we still have our subjective mental experience left over.

    We can attempt to write this leftover part off as epiphenomena or unimportant, perhaps an illusion, but that still fails to explain why it exists at all. Furthermore, this would reduce everything in science itself to epiphenomena. Einstein’s equation for mass and energy, Newton’s Laws of Motion, and Darwin’s Theory of Evolution themselves would be nothing more than illusions, epiphenomena of neurons firing. Some may willingly go down this route but we might ask them why they would prefer Darwin over Lamark or, for that matter, over intelligent design since all of them would be nothing more than neurons firing anyway. If they wish to claim neurons firing a particular way are better than neurons firing a different way, presumably the difference, then immediately a concept of value has been brought into the picture But the value itself of better proven science over conjecture or non-science is but more neurons firing. So we would have an infinite regress with no reason for preferring any idea or belief over any other since they all ultimately reduce to the same thing and, furthermore, are actually unimportant.

  15. Tom Clark says:

    “Imagine what it would entail to truly believe that consciousness is not accounted for by physics.”

    We needn’t suppose that there’s something fundamental to nature which is categorically non-physical (although some naturalists like Chalmers hypothesize there might be) or that nature is teleological to suppose that consciousness – the having of conscious experience – might not be accounted for by physics. The fact that certain physical systems like ourselves are conscious might be a function of higher level system properties, e.g., representational recursivity and limitations as suggested for instance by philosopher Thomas Metzinger (http://www.naturalism.org/appearance.htm ), not a direct entailment of physical laws. Which is to say the physics could be different and we might still have the same sorts of higher level properties responsible for consciousness. But of course the existence of consciousness has to be *consistent* with the physical laws, whatever they are.

    Nagel makes clear in his NY Times piece that he considers himself a naturalist (if not a materialist) and he writes: “It makes sense to seek an expanded form of understanding that includes the mental but that is still scientific — i.e. still a theory of the immanent order of nature.”

    I don’t think there’s any evidence that consciousness is immanent in nature or exists as a fundamental property (e.g., Chalmers’ panprotopsychism*) or, as Nagel says in the Times, that “biological evolution must be more than just a physical process.” But it isn’t unreasonable to suggest that science and philosophy may not have all the answers in hand just yet when it comes to explaining consciousness.

    * “the view that fundamental entities are proto-conscious, that is, that they have certain special properties that are precursors to consciousness” – Chalmers at http://consc.net/papers/panpsychism.pdf

  16. Bruce says:

    ” that the behavior of ordinary matter would occasionally deviate from that expected on the basis of physics alone, even in circumstances where consciousness was not involved in any obvious way….”

    Uncertainty and Godel’s Proof, each in their ways, point to limits of formal systems, where behavior exceeds predictability. The meaning of the equality of energy and matter is deeply unprobed in these discussions of the emergence of consciousness and its impact on reality.

  17. George says:

    “Imagine what it would entail to truly believe that consciousness is not accounted for by physics. It would entail, among other things, that the behavior of ordinary matter would occasionally deviate from that expected on the basis of physics alone…”

    Seems like you’re assuming (in addition to consciousness as some fundamental aspect of reality) the existence of free will among the particles. I don’t think that’s in Nagel’s argument.

  18. George says:

    Here is another comment.

    It’s seems like Nagel’s argument of a natural teleology could help explain the unique (albeit highly unlikely) characteristics of our universe to support life. As far as I understand, the only explanation on the table for this is an inflationary process after the big bang that resulted in many many universes, and we ended up in the one that can support life. I’m not exactly comfortable with this explanation, do it seem’s to me that maybe we shouldn’t be too quick to throw out Nagel’s argument. Maybe there’s something there.

    Nice post, btw.

  19. edw says:

    Ah, I see, Dr. Carroll. I was conflating the deontic “must” with the alethic “must,” to put it roughly. We have an idea of what a theory or explanation should look like (simple, powerful, etc.) and, other things being equal, we should accept those theories that look like this. But this is different from saying, say, that it is impossible for a non-simple or non-powerful explanation to fit the data.

    Thanks for your response. And inasmuch as I understand it, it helps me see more clearly where I stand: At the highest pitches of abstraction, I think, the humanly meaningful difference between what form a natural-scientific theory should take and what form a natural-scientific theory must take disappears. For instance, I would say that the two “musts” converge in the claim, “The theory – simple or not, powerful or not – must fit the data.” (Clearly, though, I have lots of explaining to do!)

  20. John Kubie says:

    Very interesting. Two comments.
    1. If we imagine dualism is true: two domains, physical and psychic (that contains consciousness). Either they interact, or they don’t. If the interaction is one-way, physical -> psychic, then the laws of physics could be complete and consistent with two domains. If they they interact in any way that the psychic -> physics, then physics is incomplete. In other words, a complete physics will involve what we are calling the psychic domain, so there is no psychic domain; just a part to the physical (material) domain that we don’t yet understand.
    2. If the psychic domain cannot influence the physical domain, I’m at a loss. Does it exist? How could it evolve?

  21. Foster Boondoggle says:

    @max and Sean: if all you care about is doing physics, you don’t need the mental. Observing that the universe contains qualia (more or less the answers to the question “what is it like to be an X”?) doesn’t entail that they cause deviations from the laws of physics. The dirac equation describes the behavior of electrons. But it doesn’t say what it’s like to be one of those electrons.

    We each know consciousness exists in the universe because we each have a single observation as evidence. We infer that it’s more widespread because we observe other things like ourselves and, with an assist from Occam, make the simple leap to assuming that the other things (people) are also conscious. Then we get into irresolvable debates about whether dolphins, apes, cats, mice, lizards, wasps, amoebas and e. coli are conscious — or, more accurately whether there’s something it’s like to be them. The debates are irresolvable because there is absolutely no physical observation one could make to decide the issue. It’s the “from the inside” vs. “from the outside” problem.

    So, yes, physics leaves something out of the description of the universe. But what it leaves out is by nature a part that has no relevance for physics. Because it’s not concerned with anything externally observable. You can assert, if you want, the non-existence of that externally unobservable thing, and I can’t disprove you, because disproof is based on public evidence. But I can still know based on my private evidence (and I think you have very similar private evidence) that you are mistaken, because there’s something it’s like to be me. The dirac equation doesn’t leap off the page and have experiences.

    None of this means Nagel is right about teleology. Though to give him a little more credit, this sounds not so very far different from Wheeler’s self-observing U. (And they were at Princeton at the same time…)

  22. John Kubie says:

    Very spooky. How did this website know about me? teleology? Duality? Oh, yeah. I’ve logged in before using this browser.

  23. vmarko says:

    @ Sean:

    “As Will says, anything you want to “add” to the laws of physics either changes the behavior of particles, or it doesn’t. If it doesn’t, it has absolutely no perceivable affect on anything, including the atoms in your brain and the sounds that you speak and the words that you type, and can safely be ignored. If it does, show me how it changes the Dirac equation.”

    Let me try to show you how… :-) As you are certainly aware, the Dirac equation does not dictate what will happen, but only dictates what is the *probability* for something to happen. The actual result of a measurement (i.e. the event that actually “happens” in nature) is random. Statistically it obeys the distribution of results predicted by the Dirac equation, but each individual event is still completely random.

    It is inside of this randomness that a “teleological agent” can influence the physical world — any particular event is random, but any sequence of these random events might still be “driven to some purpose” by an external agent.

    In other words, the teleological influence on the material world can certainly be hidden inside the measurement problem of quantum mechanics, which is by far the biggest glaring hole in our understanding of the laws of physics. :-)

    So I would say that until you give a purely materialistic resolution of the measurement problem, you cannot exclude the influence of “nonphysical” agents on the physical world, at least not by appealing to the Dirac equation. The Dirac equation doesn’t tell you what will happen, it just tells you what is the likelihood for something to happen. And that is a much weaker statement.

    HTH, :-)
    Marko

  24. Stephen says:

    “It would entail, among other things, that the behavior of ordinary matter would occasionally deviate from that expected on the basis of physics alone” – Sean Carroll
     
    “If the psychic domain cannot influence the physical domain, I’m at a loss. Does it exist? How could it evolve?” – John Kubie
     
    Okay. There are many experiments which report that conscious intent can affect the output of random number generators in small but statistically significant amounts. But other replications have failed. I believe the only fair skeptical position is to be agnostic and try to come up with some better tests. So there does exist experimental results which may be evidence of a necessary connection.
     
    I have a quantum RNG and will try it myself when I get a chance but the morass of conflicting claims makes me pessimistic of a resolution. However, empirical evidence always trumps philosophical hypothesizing.

    If you wanted some sort of teleological theory, this is where I’d start. But it would be necessary to find a way to get a robust empirical effect which can be replicated every time in order to convince the naysayers.

  25. Maxwell Marler says:

    I think you’re right about his position being uninteresting. Not going to look at this book. This is a really common critique of physicalism. Frege does a better job at showing how ‘insert Nagel’s book title here’. Mathematical objects seem more intangible than subjective experience does.

  26. Charlie says:

    Consciousness is very mysterious to me, in the same way that a particle is. Trying to ask what is consciousness is much like asking what is a particle. Which is to say that it isn’t a totally futile exercise. Is a particle a particle, wave or string? This sort of thing is how our ape brains model the natural world, and is part of everyday life as well as the scientific process. But will we ever really “know what a particle is”?

    Speaking from a purely “how-I-think-the-world-should-work” point of view, I’ve always had some sympathy for the conundrum that the world could work (and things look much like they do) without “subjective experience”, so why have it? That bothered me when I was 12 and still does today. However, I’m also not happy with the idea that this stuff (consciousness) is not material. If it can affect particles, then it is physics (whether known or not). If it can’t, then the “subjective experience” is just an ineffectual passenger. The latter is both pointless as a scientific proposition and very unsatisfying to my subjective experience.

  27. Brett says:

    I remember that ICP song; mainly that we couldn’t stop laughing at how bad it was.

    I think the reference of that song with that specific line, “fu**in’ magnets, how do they work”, has a good place in this topic.

    Other than that, this seems like, what I’ll call, a Brawndo point that Thomas Nagel is making. “Brawndo’s got what plants crave. But Brawndo’s got electrolytes.” Where is the evidence for these claims?? what logical ideas lead to this? There are 3 types of philosophers in this world, those who employ logic and those who don’t..get it? no?

  28. DennisN says:

    Amazingly well-written blog post.

    “[…] if you want to claim that what happens in our brain isn’t simply following the laws of physics, you have the duty to explain in exactly what way the electrons in our atoms fail to obey their equations of motion.”

    Yes, I fully agree.

    “Either matter obeys the laws of physics, or physics is wrong. And if you want us to take seriously the possibility that it’s wrong, you better have at least some tentative ideas about what would be a better theory.”

    Yes, definitely.

    I’ve got nothing to add – you’ve said it.

  29. If I was a bat and you cut me into a billion pieces, would you as a physicist find what holds me together?

  30. NR says:

    Sean, perhaps Max is referring to Epiphenomenalism? Is that a coherent idea in your opinion?

  31. Stephen says:

    @deeponics
    “If I was a bat and you cut me into a billion pieces, would you as a physicist find what holds me together?”
     
    Electromagnetic and strong nuclear forces.

    Edit: At only a billion pieces, you wouldn’t reach the nuclear level. So electromagnetism alone is sufficient.

    @DennisN
    As I said in my previous comment, there is some experimental evidence that consciousness can influence random number generators which, if confirmed, would probably disprove Sean’s thesis.
     

  32. kashyap vasavada says:

    There is no denial that physics has been able to explain, to an extra ordinary accuracy, a large part of nonliving natural phenomena (though not all) in the universe as perceived by our senses. But so far this excludes understanding of mind and consciousness. Even things we understand came with a very heavy price. We do not know what it means and why it works. For example, quantum mechanics (remember “most embarrassing graph in modern physics”!). Our everyday logic had to be thrown out of window. I do not agree with the argument,” will it change Dirac equation?” There could be changes like in the case of theory of relativity and quantum mechanics which did not destroy Newtonian physics. Physicists and engineers still use it routinely, not just for earth based systems but space flights also. As a related matter, I wish you guys would stop attacks against concept of God and religion. With full knowledge of quantum mechanics and relativity, why would anyone apply our everyday logic to such matters? There could be some unseen world outside our sense perceptions. Although I do not necessarily agree with Nagel, until these things are clear, it is time for cease fire between the two camps!! So cool it!

  33. yoda says:

    “For me, that’s just a misunderstanding of what kinds of explanations we can legitimately hope for.”

    And that, is why you fail.

  34. Dave Greene says:

    At first I was mystified how the once widely acclaimed Thomas Nagel could come up with such an incredible piece of quackery. Then I read Andrew Ferguson’s article in The Weekly Standard and I understood. Nagel’s writing of Mind and Cosmos was “determined by a preexisting cause, which was itself determined by another cause, and so on back to the Big Bang.” So let’s lighten up, he could not help himself :)

  35. steven johnson says:

    Jim Cross: “Why is that subjective mental experience necessary in our universe?”

    Let’s narrow that to why a human being might find subjective mental experience necessary. There is a phenomenon called “blindsight” in which a brain dysfunction leaves a person incapable of subjectively experiencing vision, even though they are not blind. These people are handicapped. Subjective experience is concretely adaptive to function.

    In general, the reports from the sense are combined into a general subjective experience called the sensorium, the last time I looked. This consciousness is a point of view. (In fact, I find it is often illuminating to reframe questions about consciousness as questions about point of view.) It is the equivalent of a cockpit display, a reporting convenience indistinguishable from a practical necessity. Consciousness, subjective experience, is a simplification, an unconscious modeling.

    There is more to consciousness than the sensorium of course. Imagination is the ability to predict the trajectory of a projectile, for one thing. The practical necessity for such a skill seems entirely natural to me, not a bit inexplicable. The notion that subjective experience is even a something, seems to me to be more inexplicable than is commonly allowed.

    Phantom limb syndrome seems to me to show very strongly that brain function is absolutely vital in generating the subjective experience of the presence of a limb that has been amputated. Yet it is clearly not an inborn, much less nonphysical phenomenon. No one born without a limb has ever reported its eerie seeming presence!

    Even for so-called higher level functions, the voices commonly heard by schizophrenics are I believe thoughts of the brain. But the schizophrenic’s brain cannot integrate these various thoughts into a single subjective experience, a single point of view, a single, simple consciousness. The resulting dysfunctionality displays the need for a subjective experience I think.

  36. Ramesam says:

    You ma have seen the essay by Meinard Kuhlmann in the recent Sci Amer. He says:
    “Physicists speak of the world as being made of particles and force fields, but it is not at all clear what particles and force fields actually are in the quantum realm. The world may instead consist of bundles of properties, such as color and shape.” This argument is being supported by at least some physicists.

    Neuroscince has clearly established the disconnect between reality and what we take it to be the reality based on our perception. What we infer to be present and the meaning we attribute to it is nothing more than our “imagination.”

    The above two facts (i. The world consists of intangible properties; and ii. the reality of “what is” is never perceived by us) do mellow us down unlike the stand taken by Sean, I believe.

    Further, “Consciousness” has to exist prior to the possibility of any perception. If you are already not there in a room, you will not be able to say if anyone has entered the room or not. So primary thing is the ability to “Know” which is Consciousness.

  37. CB says:

    po-tay-to, po-tah-AH-AH-AH-AH-ITBURNS-AHH-to.

  38. Nonphysical consciousness would not necessarily mean that “the electrons in our atoms fail to obey their equations of motion”. It could be that the electrons do what the electrons do, and the universe hallucinates a story to explain why.

  39. I think the idea of a deeper purpose to the universe (something real, not just a useful concept) is worth pursuing, and we need not ground our hopes for such a purpose in deviation from the laws of physics. Why should strict obedience to those laws imply the absence of purpose? While there may not appear to be any inherent purpose or guidedness to the laws of physics, we can’t confidently say that there isn’t one. As for consciousness, if indeed it is an emergent property of matter when arranged in the right way, that shows that there is something very profound about matter. Somehow the potential for consciousness is an inherent feature of the laws of physics – and that is breathtaking. (When we learn about emergent phenomena like consciousness we are in some sense learning about the fundamental laws – because those laws are such that they give rise to the discovered emergent phenomena.)

  40. vmarko says:

    @ Elliot Nelson:

    “As for consciousness, if indeed it is an emergent property of matter when arranged in the right way, that shows that there is something very profound about matter. Somehow the potential for consciousness is an inherent feature of the laws of physics – and that is breathtaking.”

    Be careful — if the laws of physics predict consciousness as emergent, the very same laws might predict a “god” — an all-encompassing all-knowing consciousness in the universe, by the same mechanism of emergence.

    So the materialists/naturalists/atheists are somewhat afraid to go down the route of “real consciousness emergent from physical laws”. They would rather prefer to treat consciousness as an unreal, delusional effect of our neural activity, rather than something “real”. In a sense, people are just delusionally imagining that they have something called “consciousness”, whereas in reality such a thing doesn’t actually exist. It is called an “epiphenomenon” — like an illusion that the needle of a compass is “driving” the boat that is randomly moving around on the sea.

    If you are a proper atheist, you must never accept that any consciousness (even your own) can really exist. And indeed atheists do exactly that — they claim that the existence of consciousness cannot be objectively measured in an experiment, nor can such a concept even be defined in terms of physics.

    So if you thought that you are self-conscious, it’s just a self-delusion of your consciousless brain. 😉

    Otherwise, the laws of physics, by allowing consciousness to exist as an emergent phenomenon, might open the door for god to exist as well, by the same mechanism applied on a larger scale. Everyone who is a faithful believer in atheism will firmly reject such an obscene idea with ultimate disgust… Consciousness emerging from physics? Phew, no way… 😉

    HTH, :-)
    Marko

  41. JustOneKalpa says:

    Actually we do know that consciousness effects physical entities. When a subject concentrates on a thing (say something seen) other parts of the brain are less active (like hearing). This is demonstratable using purely physical methods (fMRI for instance) and can be well described using purely physical concepts. So this “metaphysical” consciousness is part of physics and not outside it.

  42. mks says:

    lots of stuff here :3

    1. it is the role of ‘the media’ to create controversy — more controversy, more status & sales

    2. neo-darwinism is just one scientific theory out of at least 8

    3. science goes where science goes — notes like ‘physicalist’, ‘naturalist’, ‘immaterialist’ are mainly, i find, to be tribal designations

    4. ‘what causes something’ always involves a choice by us in deciding where to start by examining the process

    5. ‘material’/’immaterial’: try not to take these terms too literally. things like energy, the wave function, and ideas can be thought of as immaterial (whatever that means) and can, thus, affect the ‘material’…

  43. Tienzen (Jeh-Tween) Gong says:

    This is a very old issue. The content of this post could be reduced into one question.

    Can physics explain consciousness?

    Obviously, this is a question without a settled answer in the mainstream academia thus far. In my view, the major problem of this simple question is neither about physics nor about philosophy but is about the linguistics.

    First, *explanation* is a term of sociology, totally subjective. And, Sean Carroll has said very nicely, “People who deny that physics can ever account for consciousness have a similar idea; even if we had a complete theory that accounted for every possible observable action of purportedly conscious creatures, they would not be satisfied that this qualified as “understanding” or “explanation.” For me, that’s just a misunderstanding of what kinds of explanations we can legitimately hope for.”

    Thus, we should define the two with a *fundamental /emergent* relationship instead of explanation. Carroll said again, “Except, if mind is not physical, at some point they swerved away from those laws, since remaining in accordance with them would never have created consciousness. So, at what point does this deviation from purely physical behavior kick in, exactly? It’s the immortal soul vs. the Dirac equation problem–if you want to claim that what happens in our brain isn’t simply following the laws of physics, you have the duty to explain in exactly what way the electrons in our atoms fail to obey their equations of motion.”

    Is the *football-game* a part of Nature? If we human are part of Nature, all our activities cannot go beyond the Nature. Of course, there is no *physical-action* in the game can swerve away from the laws of physics. Yet, the *rules* of the game can be completely unrelated to the laws of physics, whatever that physics laws are or will be. That is, something *in* Nature can be completely not related to the laws of physics. One example is enough for existential introduction. Again, this is another linguistics issue. The rules of football game is not *spontaneous* emergent from the laws of physics.

    Second, is consciousness a spontaneous emergent of the laws of physics? Thus far, consciousness is defined as the **quality or state** of being aware of an external object or something within oneself. With this definition, we today obviously have not found any fundamental/emergent relation between it and the physics laws. If we can change this definition very slightly to “consciousness is the *ability* of distinguish a *self* from the others” (that is, by a system of individuality), then there is a *four-color theorem* available for our use. This four-color theorem guarantees that unlimited (perhaps infinite) number of mutually distinguishable balls can be produced. Thus, every four-color system can guarantee the manifestation of a system of *individuality*. As far as we know, *life* is a four-color system, with (A, G, T, C) as genetic-colors. If a four-color system is also embedded in physics laws, then a spontaneous emergent relation between consciousness and physics laws could be established.

  44. Aleksandar Mikovic says:

    There is a simple plausibility argument which shows why materialism is a bad metaphysics for science: Let us assume that there is only space, time, matter and a finite set of natural laws governing the motion of matter. The standard materialist belief is that this can explain in principle any phenomena in the universe (including consciousness and intelligent beings). Also, let us assume that these natural laws can be expressed with a finite set of symbols. Then by Goedel’s theorems, we know that such a formal system is incomplete, i.e. there will be statements (phenomena) which can not be derived (explained) from the basic postulates (natural laws). Such phenomena can be added to our finite list of natural laws, and there are infinitely many of these. A materialist can than say, OK, I cannot have a Theory of Everything, but still the universe is materialistic. However, having an infinitely many elements (natural laws) which are not matter, means that one is introducing new objects in his metaphysics, and since these objects are mathematical in nature, one arrives at a Platonic world of ideas. A die hard materialist can that say, OK, throw away the laws, i.e. consider them as some random regularities in the chaotic motion of particles, but then one has to accept that such a regularity is lasting 15 billion years, and that tomorrow, everything can fall apart. Although a logical possibility, it is a very implausible one. This would also mean that a fundamental explanation for any phenomena is that it simply occurs by chance. From the philosophical point of view, such a belief is the same as solipsism.

  45. Pingback: Nagel’s bat doesn’t demonstrate incompleteness in materialist science | coelsblog

  46. steven johnson says:

    ^^^I should think that truths that cannot be derived a priori from a sufficiently rich mathematical system are the ones that are subsequently discovered empirically. The math’s inability to prove all possible consequences of its axioms seems to me a proof that any form of mathematical Platonism fails. (And by extension, any version of ontological structural reality.)

    Doesn’t this argument rely on an extreme predictivist view of science? Popperism ashamed to confess itself?

  47. bstr says:

    Sean, i think Jim Cross makes a useful observation here: “Clearly there is something left over beyond the sensual and neural mechanism that underlie my perception, something beyond chemicals, neurons, and electrical activity. That something is my experience of the gray bark, the sunlit side of the tree, and the blue sky. Even if reductionism could explain in detail everything at the physical level that makes perception happen, it cannot explain the why of my subjective experience” and i’m wondering if you are familiar with Jesse Bering’s The Belief Instinct, and his considerations of Theory of Mind as an adaptive trait which has come to such extensive sophistication that it is responsible for our inner conversations? And Cross seems to be about such inner conversations.

  48. Aleksandar Mikovic says:

    Although Goedel’s theorems in the context of a platonic metaphysics imply that mathematics (science) cannot explain everything, one also has to take into account that there are ideas (truths, phenomena) that are non-mathematical, i.e. cannot be completely described by a finite set of symbols and rules. Still, the human mind is able to see such ideas.

  49. Matthew says:

    I feel like the fundamental stance of people like Nagel is that “understanding” is something that can only happen through experiential evidence. At that point, no matter what your theory is, we’ll never have something complete.
    Suppose we create a way for people to experience what it’s like to be someone or something else. For the purposes of this argument it doesn’t matter whether this process is developed purely using physics or not. There are far too many things to experience to possibly be able to say that we understand them all in the way that Nagel and others are hoping for.
    I find that it’s best not to develop your theories because some implication of current theories makes you uncomfortable. That’s a sure-fire way to incorporate poor reasoning somewhere in your argument.

    Great article Sean

  50. Higguns says:

    Aleksander,

    I present the same challenge to you: give me an example of something that science can’t completely describe but the human mind is still able to see.

    Jim Cross’s example is: “it cannot explain the why of my subjective experience”. This is a clever statement in that it has no meaning and therefore can’t be answered. What do you mean by “the why of my subjective experience”? The only thing you could mean is why do we exist? Just as there are eternal numbers, this is an eternal question that seemingly never has an answer. Every time you gain an answer, then you also gain another question: “why is that the answer?”. You’re entire argument can be boiled down to an indeterminate question that has no real meaning. “Why?”. Why what? Why who? There is no answer because it doesn’t actually ask a question.