Are Qualia Epiphenomenalia?

A lively discussion has been going on over at Bill Vallicella’s website. I seem to be spending so much time over there, in such engaging company, that I am getting very little done in here!

One of the topics we’ve been grappling with is the physicalist view of the mind. As you might have guessed from previous posts, I hold the view that our minds are entirely grounded in the physical world: that all of our thoughts, memories, fears, imaginings, etc. – in short, our inner lives – are the result of the activity of our physical bodies, in particular our nervous systems. We are a long way from completing the scientific program that will exhaustively map subjective experience onto objectively measurable physical states and transactions, but I do believe, along with most scientists studying the problem, that the idea is sound, and the goal attainable, in principle at least. But this view, all but hegemonic among research scientists, has met considerable resistance in the philosophical community. A recent posting at Dr. Vallicella’s site sums it up:

Marvelously complex as it is, the brain is just another chunk of the physical world. Study it till doomsday with the most sophisticated instruments, map every cubic millimeter of it, establish detailed correlations between brain regions and types of conscious phenomena — and what do you accomplish? You learn more and more about a highly complex piece of meat.

In other words, one might exhaustively map the entire state of the human body, all the way down to the patterns of neural activity in the brain, and still have some ineffable thing left over. For example, given the technology for a full neural-state scan, we might study a subject, and be able to declare with certainty that now she is thinking, say, of a piece by Brahms, and now she is remembering that she left the light on at home, and furthermore, if we excite this glial bundle right here she will suddenly feel a sense of humorous irony, and will laugh a wistful laugh, while if we stimulate this neuron over here she will hear a distant bell ringing – but even if we can do all of that with perfect reliablity, still something will be left out. That something is usually declared to be the subject’s inner experience, what it is like to be that person: the way the colors look, the way the music sounds, and so on. These subjective experiences are referred to as qualia (KWAH-lee-ah), and are considered by some to be inaccessible to any third party, and to be utterly irreducible to any physical description. In other words, there is the physical stuff of the world – our bodies – and then there is this other Thing: as real as can be – what could be realer than our own experiences? – but having no objective existence. Meat and Mind. This is called “dualism”, and it is an idea that goes a long way back.

Dualism is very tempting – it does seem that our mental states are of a very different quality than anything else in the world. They lack the permanance of physical objects, and unlike anything else we know of, they can be directly perceived only by one person. It is easy to imagine that they are separate, somehow, from the coarse matter of the world. But there are difficulties with this idea, foremost of which is that of understanding how a nonmaterial entity can get a grip on ordinary matter. If the actions of my body are driven in an uncontroversial way by my nervous system, then how does the immaterial Mind, in turn, drive the nervous system? What is the point of contact? How can non-material mental states drive the body into correlated physical states? How can a presumably undetectable non-physical entity do this without, for example, violating physical conservation principles? Likewise, how can a “quale” (that’s KWAH-lay, singular of “qualia”) have a purely non-physical existence? This seems less problematic until one realizes that qualia are easily connected to macroscopic causal chains in the physical world, as, for example, when I stop my car upon experiencing the “redness” of a traffic signal. There aren’t many exits here. One is simply to insist, on intuitive grounds, that our minds simply can’t be grounded in material processes, because it should be obvious that material processes just can’t produce minds. This is the bias represented in the quote above; implicit in the statement is the conviction that learning “more and more about a highly complex piece of meat” will never get you any closer to Mind, even though the particular piece of meat in question is no ordinary skirt-steak, but rather the most complex object, as far as we know, in the entire Universe.

Another way out is “epiphenomenalism”. This is a word that is used in two different ways, and sometimes the confusion is exploited by using it both ways in the same argument. Here are the two meanings of “epiphenomenon”, one used by scientists generally (in particular evolutionary theorists), and one used in a very strict sense by philosophers :

In the looser sense, an epiphenomenon is a nonfunctional trait that rides along with some useful or adaptive behavior. Daniel Dennett [Consciousness Explained, pp 401-402] gives the examples of the hum created by a computer, or the shadow you cast on the counter as you make a cup of coffee. Neither hum nor shadow serves any function related to the purpose at hand. To an evolutionary biologist, these epiphenomena are adaptively neutral traits that either ride along simply because there is no selection pressure against them, or because they are an inevitable but non-functional adjunct to some selected feature (Gould famously called such things “spandrels”). Epiphenomena like these, while having no bearing on the feature or function to which they are related, still have an obvious physicality – one can make physical recordings of the computer’s hum, measure the cooling effect of the shadow, etc. There is no room for a non-physical Mind here.

The stricter meaning of the word is that something is an epiphenomenon if it is caused by some phenmomenon in the physical world, but itself has no effect on the world. Such an entity is utterly undetectable by any physical means, and can have no influence whatsoever on the course of the world’s events. Yes, qualia could be of this nature, but then you would never be able to tell anyone about them, act on their content, or, as Dennett points out, act differently in any way than you would if you didn’t have them. This is obviously rather unsatisfactory as well, but it is taken up as a last resort by those who need to carve out a special place for the subjectivity of our experience: our qualia are quite real, and quite non-physical, but do not interact causally with our physical selves at all – such states are instead simply correlated with the physical activity of the brain. This seems like a particularly bleak view – our minds as feckless epiphenomenal ghosts, trapped in our bodily vehicles with no access to the controls. The world would be no different if we didn’t have them at all. And it is hard to argue convincingly that something like that even exists.

One way out is to see the brain as a purely physical system, driven into “reactive states” by the interaction of incoming sensory data with the brain’s previous state. Our awareness of “qualia” would then be detectable, in principle, by a complete analysis and understanding of the current reactive state of the brain. This leaves no room for the mysterious something “extra”, something transcendantly non-physical, that dualists are fighting for, but it seems to me to be the only model that plausibly accounts for the mounting neurological evidence of extremely tight coupling between the physical and the mental.

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18 Comments

  1. Good post, Malcolm. I’ll respond at length over on my blog.

    “but then you would never be able to tell anyone about them, ”
    Why do you say this?

    You can’t help yourself to the term qualia once you have reduced them to brain states: for then there are no qualia.

    Posted September 21, 2005 at 6:33 pm | Permalink
  2. Malcolm says

    Hi Bill,

    Thanks for visiting.

    I say this because if qualia are “strictly” epiphenomenal – that is to say that the “experiencing” is completely independent of, and disconnected from, the physical state of the brain, then the qualia cannot affect the physical world in any way, including causing physical speech acts.

    Just to be clear, though, I don’t deny that I have a subjective experience of color, for example. All I am denying is the idea that qualia are irreducibly non-physical.

    There aren’t any unicorns, either, but I can still help myself to the term!

    Malcolm

    Posted September 21, 2005 at 6:48 pm | Permalink
  3. Kevin Kim says

    “You can’t help yourself to the term qualia once you have reduced them to brain states: for then there are no qualia. ”

    Sure you can. Define qualia as synonymous with those brain states. It’s not a move that’ll satisfy the non-materialist, but there’s nothing about qualia that makes the term off-limits to non-non-materialists.

    Kevin

    Posted September 23, 2005 at 2:12 am | Permalink
  4. Spur says

    Hi Malcolm,
    Unfortunately, the version of dualism I sketched over on Bill’s site is quite different from both of your versions of epiphenomenalism. It construes the mind as something non-physical (thus distinguishing itself from the looser, scientific kind of epiphenomenalsim), and it denies that mental states have a physical cause (thus distinguishing itself from the stricter, philosophical kind of epiphenomenalism).

    Actually, the view I am proposing sounds closer to the one expressed in this sentence: “our qualia are quite real, and quite non-physical, but do not interact causally with our physical selves at all – such states are instead simply correlated with the physical activity of the brain.” But this isn’t epiphenomenalism of any sort, since, as you correctly point out, (strict) epiphenomenalism is the view that the physical causally influences the mental, but not vice versa.

    You go on to characterize the no-interaction view as “particularly bleak,” but your criticism misses the mark. You say that on this view we would be “trapped in our bodily vehicles with no access to the controls.” But that isn’t so. Suppose I will to raise my right arm. That is a mental event, something over which I have control (by hypothesis). But if I thus will, then my arm will rise, since physical events are correlated with mental ones. Of course, it isn’t the case that my arm rises because it is directly moved by my will, but the explanation for why my arm rose will still be this: I willed it to be so, and my arm had to go up in order for the correlation between mind and body to be maintained. So there is a kind of ideal influence–but no real, causal influence–of my mind on my body. So we still have access to the controls, even though causal interaction between mind and body is denied.

    Posted September 25, 2005 at 1:29 am | Permalink
  5. Bob Doyle says

    Not intending to be offensive here, and I hate to admit my “spoof” meter doesn’t give me a clear reading on this, so I really want to know. Is Spur doing an “Onion” piece here or is s/he actually serious?

    Posted September 25, 2005 at 8:48 pm | Permalink
  6. Malcolm says

    Well, I’m not sure what to make of this. If the mind just mirrors the activity of the brain/body in some ghostly way, but has no influence on anything, I don’t really see how that is an “ideal” influence, or any sort of influence at all.

    I am more and more drawn to a view in which consciousness ebbs and flows as the need for higher-level integration of different mental modules rises and falls (this is pretty much what Dennett suggests in his Multiple Drafts model). It might be that consciousness provides somehow a useful feedback mechanism for this process. This would tie in nicely with the idea of creating a more integrated Self that is the goal of meditative disciplines. Meditation would be a sort of biofeedback for the brain – by the effort of attention that is at the heart of these practices we would foster the ability of the brain to “bootstrap” these integrative processes.

    I need to think about this some more.

    Posted September 27, 2005 at 12:41 am | Permalink
  7. Spur says

    Bob: I am serious. The view I am proposing was first proposed by G.W. Leibniz, the great German mathematician, physicist, and philosopher. He was serious too.

    One aspect of the view that I didn’t make explicit is that God is the one who sets things up so that the mental and physical are perfectly correlated with one another. Malcolm, what I mean by ideal influence is just this: in setting up the world with this mind-body harmony, God sometimes “adjusts” the body to the mind, and other times “adjusts” the mind to the body. In the former case, the body has a kind of ideal influence on the mind, since it contains the reason why the mind is the way it is. In the latter case, the mind has a kind of ideal influence on the body.

    Posted September 27, 2005 at 3:31 am | Permalink
  8. Malcolm says

    Hi Spur,

    Thanks for the clarification – I wasn’t sure which view, exactly, you were championing. This version of things, for those readers who might not be familiar with it, is called “occasionalism“, and, relying as it does on an extremely interventionist God, has few proponents these days. A Deity who merely tallied the fall of every sparrow would be a downright slacker by comparison.

    One objection to this view is that if God is going to be such a meddler in everything it becomes hard to see why there are any natural laws or regularities in the world at all. It begins to remind one of the Flying Spaghetti Monster’s Noodly Appendage.

    Malcolm

    Posted September 27, 2005 at 10:24 am | Permalink
  9. Spur says

    Sorry, Malcolm, but the view I’m proposing is decidedly not occasionalism. I am suggesting that God is not an interventionist, but that he sets the laws (both those governing physical things and those governing mental things) up in the beginning so that mental and physical will be in harmony. This is a much more elegant and attractive picture than the occasionalist one, as Leibniz recognized.

    Posted September 28, 2005 at 10:44 am | Permalink
  10. Malcolm says

    Hi Spur,

    Sorry if I misunderstood you; you can see why the phrase “God sometimes adjusts” would make one think you were talking about occasionalism (you might as well have said “God occasionally adjusts…”).

    So God built this correlation in from the beginning? Into what, exactly? There weren’t any human minds around early on in need of this sort of synchronization (if we accept evolutionary history, that is, which of course we do here at waka waka waka).

    If there were preexisting laws governing, separately, mental “things” as distinct from physical things, it is an interesting question what conditions needed to be met for the two to hook up.

    Malcolm

    Posted September 28, 2005 at 11:02 am | Permalink
  11. Spur says

    Yes, Malcolm, you are right: my choice of words was misleading. Sorry about that. God built the correlation into the laws in the beginning. One could deny, as Leibniz and many others have, that minds arrived on the scene only when humans evolved. It could be that human minds have always been around, though not as minds. (They only achieved that elevated status as they evolved along with humanity.) Over time, brains evolved to be more complex, capable of higher functions, such as those that occur when we are conscious or engaged in abstract thought. During this time, the mind-like things that are now our minds were evolving to become more complex, capable of higher functions, such as consciousness and abstract thought themselves.

    Posted September 28, 2005 at 3:05 pm | Permalink
  12. Malcolm says

    Hi Spur,

    Sorry, but I don’t really follow what you mean by “mind-like things”, or by saying that “human minds have always been around, though not as minds”. I get the feeling that you are saying that some sort of proto-minds were evolving in parallel with “body-based” lifeforms. But, some questions: First, is it fair to assume that we now have one mind per human, in a one-to-one mapping? Back when life consisted solely of blue-green algae and such like, where were these “mind-like things”, how many of them were there, and how did they map onto the organisms of the day? One “MLT” per single-celled organism? The whole thing seems barely coherent to me, if at all.

    Posted September 28, 2005 at 3:43 pm | Permalink
  13. Spur says

    “I get the feeling that you are saying that some sort of proto-minds were evolving in parallel with ‘body-based’ lifeforms.”

    That seems fairly accurate.

    “First, is it fair to assume that we now have one mind per human, in a one-to-one mapping?”

    That’s roughly correct, though the minds of humans now dead and yet to be alive currently exist; they’re just in a state of dormancy. Functionally, they aren’t currently minds, but I suppose there’s a sense in which they could be said to be minds.

    “Back when life consisted solely of blue-green algae and such like, where were these ‘mind-like things’?”

    They’re not located in space, so they weren’t anywere.

    “How many of them were there, and how did they map onto the organisms of the day?”

    There were as many of them as there were organisms in that day. The proto-minds mapped on to the organisms one-to-one.

    “One “MLT” per single-celled organism?”

    Yes.

    This may seem bizarre, I admit, but where’s the incoherence? We should be slow to accuse a thinker as great as Leibniz of outright incoherence.

    Posted September 28, 2005 at 10:15 pm | Permalink
  14. Malcolm says

    Hi Spur,

    So, let’s see where this goes. Unicellular organisms reproduce by mitososis – mulitplying by dividing, as it were. These putative proto-minds track right along, I assume. But when unicellular organisms entered into communities, leading to multicellular life, the protominds dutifully merged too, and when sexual reproduction of such colonies entered the picture, the “mind-like-things” were able to keep up with that, as well. And when things happen like a single blastocyst splitting into what will become identical twins, the correlated immaterial minds divide right along. And when two twins are conjoined at the hip, we have two MLTs, but if they are joined at the brain, we have one, or one and a half, or something. And if I suffer a stroke that reduces my mental functioning to near-vegetative levels, my associated MLT suffers equivalent damage as well.

    Doesn’t this all sound just impossibly contrived? A galaxy of invisible, undetectable, immaterial mind-ghosts, utterly bound and enslaved to their coarse material “buddies”, having no effect on the physical world whatsoever, but carefully prepared and maintained all the same from the dawn of time, just for God’s unfathomable purpose?

    I hope you will forgive me if I am slow to embrace this hypothesis.

    As for Liebniz, he can be forgiven, since his consideration of these matters was limited, I am sure, to human beings, as Darwin and his explication of the evolutionary story were still far in the future. I very much doubt, though, that Liebniz would sign on for what we have just described.

    Malcolm

    Posted September 29, 2005 at 11:07 am | Permalink
  15. Spur says

    “Unicellular organisms reproduce by mitososis – mulitplying by dividing, as it were. These putative proto-minds track right along, I assume.”

    “And when things happen like a single blastocyst splitting into what will become identical twins, the correlated immaterial minds divide right along.”

    We needn’t say such things. Unicellular organisms and blastocysts might be composed of multiple smaller organisms, so that when they divide or split, each part corresponds to some MLT.

    “And when two twins are conjoined at the hip, we have two MLTs…”

    That seems right.

    “… but if they are joined at the brain, we have one, or one and a half, or something.”

    This case presents no special problem for Leibniz’s view. We have to ask ourselves whether in this joined-at-the-brain case we think there is one mind or two. If we think there is only one mind, then Leibniz can say that there is only one MLT associated with this brain. If we think there are two minds, then he can say that there are two associated MLTs.

    “And if I suffer a stroke that reduces my mental functioning to near-vegetative levels, my associated MLT suffers equivalent damage as well.”

    That’s essentially right.

    “Doesn’t this all sound just impossibly contrived? A galaxy of invisible, undetectable, immaterial mind-ghosts, utterly bound and enslaved to their coarse material “buddies”, having no effect on the physical world whatsoever, but carefully prepared and maintained all the same from the dawn of time, just for God’s unfathomable purpose?”

    Several comments. (1) These MLTs aren’t exactly undetectable, since according to the theory you are one yourself. (2) These MLTs are partially enslaved to their bodies, but the bodies are also partially enslaved to the MLTs. It goes both ways. (3) They aren’t prepared and maintained in this way “just for God’s unfathomable purposes.” Rather, they are prepared and maintained in this way, at least in part, in order to allow for such things as consciousness and reason in this world. Of course, if a plausible case could be made out for a materialist account of consciousness and related phenomena, then this theory would have to be abandoned. But Leibniz thought, and Bill has been arguing, that no such case can be made. I am inclined to agree, which is why I consider this theory worth thinking about. It is the best alternative we have to materialism, and the best version of dualism we have. But if materialism can be vindicated one day, I’ll be the first to give it up.

    Posted September 29, 2005 at 4:18 pm | Permalink
  16. Malcolm says

    Hi Spur,

    Well, I will stop pointing out practical weaknesses in this model, because it is easy enough for you simply to postulate fancy new features as fast as they are needed. There is nothing whatsoever that anyone could possibly grab hold of to refute this hypothesis, as it makes no testable claims whatsoever. It is like the example given by Dennett of there being fourteen epiphenomenal gremlins in every cylinder of an internal combustion engine:

    “They have no mass, no energy, no physical properties; they do not make the engine run smoother or rougher, faster or slower. There is and could be no empirical evidence of their presence, and no empirical way in principle of distinguishing this hypothesis from its rivals: that there are thirteen or fifteen gremlins.”

    Why on earth should anyone believe such things?

    Malcolm

    Posted October 6, 2005 at 4:19 pm | Permalink
  17. David C says

    Has it ever occured to any of you that body and mind are both made out of something that is neither body or mind?

    By this I mean that body and mind are different forms of the same substance — said substance being neither bodily nor mental.

    Has this thought ever occured to any commenter here?

    Posted October 9, 2005 at 4:29 am | Permalink
  18. Malcolm says

    Hi David,

    I’m sorry not to have responded sooner – somehow I missed the email that should have alerted me to the arrival of your comment.

    We see all around us the physical substance of the world; the physicalist view is that the mental is not “substance” at all, and that there is no need for multiplying entities in this way. The mental is an emergent property of the physical.

    A physicalist might say that mental and physical are different aspects of the the same substance – the ordinary matter of the world, while the dualist proposes another type of substance. Can you elaborate on the distinction you are trying to make?

    Posted October 30, 2005 at 7:52 pm | Permalink