Tag Archives: subjective experience

What’s Wrong with Dualism?

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I had an email exchange with Philip Calcott recently about dualism; here’s an edited version. (Favouring my bits of the dialogue, of course!)

Philip: The main issue that puzzles me regarding consciousness is why most people in the field are so wedded to physicalism, and why substance dualism is so out of favour. It seems to me that there is indeed a huge explanatory gap – how can any physical process explain this extraordinary (and completely unexpected on physicalism) “thing” that is conscious experience?

It seems to me that there are three sorts of gaps in our knowledge:

1. I don’t know the answer to that, but others do. Just let me just google it (the exact height of Everest might be an example)
2. No one yet knows the answer to that, but we have a path towards finding the answer, and we are confident that we will discover the answer, and that this answer lies within the realm of physics (the mechanism behind high temperature superconductivity might be an example here)
3. No one can even lay out a path towards discovering the answer to this problem (consciousness)

Chalmers seems to classify consciousness as a “class 3 ignorance” problem (along the lines above). He then adopts a panpsychism approach to solve this. We have a fundamental property of nature that exhibits itself only through consciousness, and it is impossible to detect its interaction with the rest of physics in any way. How is this different from Descartes’ Soul? Basically Chalmers has produced something he claims to be still physical – but which is effectively identical to a non-physical entity.

So, why is dualism so unpopular?

I think there are two reasons. The first is not an explicit philosophical point, but more a matter of the intellectual background. In theory there are many possible versions of dualism, but what people usually want to reject when they reject it is traditional religion and traditional ideas about spirits and ghosts. A lot of people have strong feelings about this for personal or historical reasons that give an edge to their views. I suspect, for example, that this might be why Dan Dennett gives Descartes more of a beating over dualism than, in my opinion at least, he really deserves.

Second, though, dualism just doesn’t work very well. Nobody has much to offer by way of explaining how the second world or the second substance might work (certainly nothing remotely comparable to the well-developed and comprehensive account given by physics). If we could make predictions and do some maths about spirits or the second world, things would look better; as it is, it looks as if dualism just consigns the difficult issues to another world where it’s sort of presumed no explanations are required. Then again, if we could do the maths, why would we call it dualism rather than an extension of the physical, monist story?

That leads us on to the other bad problem, of how the two substances or worlds interact, one that has been a conspicuous difficulty since Descartes. We can take the view that they don’t really interact causally but perhaps run alongside each other in harmony, as Leibniz suggested; but then there seems to be little point in talking about the second world, as it explains nothing that happens and none of what we do or say. This is quite implausible to me, too, if we’re thinking particularly of subjective experience or qualia. When I am looking at a red apple, it seems to me that every bit of my subjective experience of the colour might influence my decision about whether to pick up the apple or not. Nothing in my mental world seems to be sealed off from my behaviour.

If we think there is causal interaction, then again we seem to be looking for an extension of monist physics rather than a dualism.

Yet it won’t quite do, will it, to say that the physics is all there is to it?

My view is that in fact what’s going on is that we are addressing a question which physics cannot explain, not because physics is faulty or inadequate, but because the question is outside its scope. In terms of physics, we’ve got a type 3 problem; in terms of metaphysics, I hope it’s type 2, though there are some rather discouraging arguments that suggest things are worse than that.

I think the element of mystery in conscious experience is in fact its particularity, its actual reality. All the general features can be explained at a theoretical level by physics, but not why this specific experience is real and being had by me. This is part of a more general mystery of reality, including the questions of why the world is like this in particular and not like something else, or like nothing. We try to naturalise these questions, typically by suggesting that reality is essentially historical, that things are like this because they were previously like that, so that the ultimate explanations lie in the origin of the cosmos, but I don’t think that strategy works very well.

There only seem to be two styles of explanation available here. One is the purely rational kind of reasoning you get in maths. The other is empirical observation. Neither is any good in this context; empirical explanations simply defer the issue backwards by explaining things as they are in terms of things as they once were. There’s no end to that deferral. A priori logical reasoning, on the other hand, delivers only eternal truths, whereas the whole point about reality and my experience is that it isn’t fixed and eternal; it could have been otherwise. People like Stephen Hawking try to deploy both methods, using empirical science to defer the ultimate answer back in time to a misty primordial period, a hypothetical land created by heroic backward extrapolation, where it is somehow meant to turn into a mathematical issue, but even if you could make that work I think it would be unsatisfying as an explanation of the nature of my experience here and now.

I conclude that to deal with this properly we really need a different way of thinking. I fear it might be that all we can do is contemplate the matter and hope pre- or post-theoretical enlightenment dawns, in a sort of Taoist way; but I continue to hope that eventually that one weird trick of metaphysical argument that cracks the issue will occur to someone, because like anyone brought up in the western tradition I really want to get it all back to territory where we can write out the rules and even do some maths!

As I’ve said, this all raises another question, namely why we bother about monism versus dualism at all. Most people realise that there is no single account of the world that covers everything. Besides concrete physical objects we have to consider the abstract entities; those dealt with in maths, for example, and many other fields. Any system of metaphysics which isn’t intolerably flat and limited is going to have some features that would entitle us to call it at least loosely dualist. On the other hand, everything is part of the cosmos, broadly understood, and everything is in some way related to the other contents of those cosmos. So we can equally say that any sufficiently comprehensive system can, at least loosely, be described as monist too; in the end there is only one world. Any reasonable theory will be a bit dualist and a bit monist in some respects.

That being so, the pure metaphysical question of monism versus dualism begins to look rather academic, more about nomenclature than substance. The real interest is in whether your dualism or your monism is any good as an elegant and effective explanation. In that competition materialism, which we tend to call monist, just looks to be an awfully long way ahead.

Hippocampal holodeck

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Matt Faw says subjective experience is caused by a simulation in the hippocampus – a bit like a holodeck. There’s a brief description on the Brains Blog, with the full version here.

In a very brief sketch, Faw says that data from various systems is pulled together in the hippocampal system and compiled into a sort of unified report of what’s going on. This is sort of a global workspace system, whose function is to co-ordinate. The ongoing reportage here is like a rolling film or holodeck simulation, and because it’s the only unified picture available, it is mistaken for the brain’s actual interaction with the world. The actual work of cognition is done elsewhere, but this simulation is what gives rise to ‘neurotypical subjective experience’.

I’m uneasy about that; it doesn’t much resemble what I would call subjective experience. We can have a model of the self in the world without any experiencing going on (Roger Penrose suggested the example of a video camera pointed at a mirror), while the actual subjectivity of phenomenal experience seems to be nothing to do with the ‘structural’ properties of whether there’s a simulation of the world going on.

I believe the simulation or model is supposed to help us think about the world and make plans; but the actual process of thinking about things rarely involves a continuous simulation of reality. If I’m thinking of going out to buy a newspaper, I don’t have to run through imagining what the experience is going to be like; indeed, to do so would require some effort. Even if I do that, I’m the puppeteer throughout; it’s not like running a computer game and being surprised by what happens. I don’t learn much from the process.

And what would the point be? I can just think about the world. Laboriously constructing a model of the world and then thinking about that instead looks like a lot of redundant work and a terrible source of error if I get it wrong.

There’s a further problem for Faw in that there are people who manage without functioning hippocampi. Although they undoubtedly have serious memory problems, they can talk to us fairly normally and answer questions about their experiences. It seems weird to suggest that they don’t have any subjective experience; are they philosophical zombies?

Faw doesn’t want to say so. Instead he likens their thought processes to the ones that go on when we’re driving without thinking. Often we find we’ve driven somewhere but cannot remember any details of the journey. Faw suggests that what happens here is just that we don’t remember the driving. All the functions that really do the cognitive work are operating normally, but whereas in other circumstances their activity would get covered (to some extent) in the ‘news bulletin’ simulation, in this case our mind is dealing with something more interesting (a daydream, other plans, whatever), and just fails to record what we’ve done with the brake and the steering wheel. But if we were asked at the very moment of turning left what we were doing, we’d have no problem answering. People with no hippocampi are like this; constantly aware of the detail of current cognition, stuff that is normally hidden from neurotypically normal people, but lacking the broader context which for us is the source of normal conscious experience.

I broadly like this account, and it points to the probability that the apparent problems for Faw are to a degree just a matter of labelling. He’s calling it subjective experience, but if he called it reportable subjective experience it would make a lot of sense. We only ever report what we remember to have been our conscious experience: some time, even if only an instant, has to have passed. It’s entirely plausible that that we rely on the hippocampus to put together these immediate, reportable memories for us.

So really what I call subjective experience is going on all the time out there; it doesn’t require a unified account or model; but it does need the hippocampal newsletter in order to become reportable. Faw and I might disagree on the fine philosophical issue of whether it is meaningful to talk about experiences that cannot, in principle, be reported; but in other ways we don’t really differ as much as it seemed.