Blog powered by Typepad

« Time and consciousness | Main | Fields medals »

July 31, 2006



This is oddly reminiscent of Robert Wright's conviction that he'd caught out Dennett in a major change of stance. Of course in that case the whole exchange was on tape, and everybody could watch it and make up their own minds.... (For the record, I thought that Wright was absurdly eager to interpret a minor linguistic ambiguity in an implausible way.)

One thing that I would be interested to hear from both you and Dan is this: is your position falsifiable in principle? Could a repeatable experimental result cause either of you to concede that your position was wrong (and, for bonus points, that the other was correct)? If so, what would each experiment entail?

Tanasije Gjorgoski

Hi Dave,
Are you sure there isn't zombie Chalmers walking around and talking to Dennett ? That would explain it.

Pete Mandik

I too would be interested in the Dave/Dan answers to Geoff's questions. Also cool would be a metaphilosophical grudge-match over the questions of whether and why(/why not) in principle and experimental falsifiability matters to philosophical theorizing.

John Pourtless

Puccetti discussed falsifiability vis-a-vis philosophical investigations of of the body/mind problem a while back, starting (IIRC), in a publication co-authored with R. W. Dykes in 1978. His 1985 discussion in the Currie/Musgrave volume on Popper's philosophy and the humanities is of great value in this regard. Of course I should be of the inclination that any philosophical argument which entails empirically testable positions is consequently open to empirical refutation.

robert allen

Prof. Chalmers,

Prof. Dennett a Cartesian dualist? That's a joke, right?

While we're on the subject, I've often wondered why your 2-D argument did not not lead YOU to become one. I myself find the idea that material substances have non-physical properties more implausible than the idea that spirits exist.


Geoff: This isn't a straightforward empirical disagreement, but a foundational disagreement about the relationship between third-person data (about brain, behavior, etc) and first-person data (about conscious experience). To oversimplify, Dennett thinks that the problem of explaining first-person data is subsumed in the problem of explaining third-person data (explain all the functions/reactions/reports and you've automatically explained consciousness), while I think that there is a further problem of explaining first-person data over and above explaining third-person data. As such, it's obvious that third-person experimental data alone won't settle the issue. I think that there's a sense in which Dennett's position is falsified by the first-person data, but obviously he doesn't agree about that. So it doesn't look like the debate will be settled in the laboratory.

Pete: I don't have a strong metaphilosophical view here. Philosophy is a big tent: some bits of it are a long way removed from science, some bits are continuous with scientific debates, and some are in between. Obviously I don't think that experimental falsifiability is a sine qua non -- that would rule out huge chunks of philosophy, not to mention a number of foundational debates in science, such as the issue between distinct empirically equivalent interpretations of quantum mechanics. But that's not to say that philosophy should be held aloof from scientific work. Certainly I think that a proponent of a philosophical view should at least be able to make the case that their view is compatible with the available empirical data, and where possible, make the case that it integrates reasonably well with relevant empirical science. That's what I've tried to do, e.g. in "How Can We Construct a Science of Consciousness?".

Robert: On your first point, see the small print. On your second point, I've never argued that substance dualism is false. The anti-materialist arguments I've given make the case that there are nonphysical properties. They don't make the case that there are nonphysical substances, but neither do they rule it out. I'm not quite sure what it is to be a "substance", so I'm not sure exactly what the issue is. If the issue is whether there are nonphysical particulars as well as nonphysical properties, then I'm reasonably sympathetic with a "yes" answer, but again it's not something that I claim to have a good argument for.

Bryan Frances

Hi Dave,

Could you tell us your view on the relation between properties and particulars? You seem to hold that although you have a good argument that there are non-physical properties, you can't easily turn it into a good argument for non-physical particulars.


robert allen

David (if I may),

Thank you for replying.

Ah, the fine print. Good thing I'm not an attorney.

To follow up on Prof. Frances' question (before you've even had a chance to answer it), I take substances to be the bearers of properties (or that in which they inhere, as Aristotle puts it in the Categories). If you accept the arguments against the bundle/collectionist theory (cf. Hoffman and Rosenkrantz's magisterial Substance Among other Categories), then you are forced to posit such entities. Thus, the non-physical properties established by your argument either belong to material substances- our bodies, implausible by my lights- or spirits. In other words, in refuting reductionist accounts of consciousness, I take you to have eo ipso cinched the case for Cartesian dualism and wonder why you prefer thinking of consciousness as a non-physical feature of a human body, which is my understanding of property dualism.

p.s. You are a heckuva photographer; I really enjoy your pictures of folks at conferences.

Pete Mandik

Hi Dave,

Thanks for your responses re: falsifiability.

I wouldn't be surprised to find out that Dennett agrees with you that the debate won't be settled in the laboratory. The way you framed your response to Geoff in terms of first- and third-person data inspires some further related questions. Supposing that the Dennett/Chalmers disagreement is indeed underdetermined by third-person data, I wonder what, if anything, you guys might regard as potentially falsifying first-person data.

I suppose that there are also interesting questions concerning falsifiabilty aside from those pertaining to data. Experiments and introspection aside, what sorts of considerations could possibly convince you of the falsity of your position? You've indicated elsewhere that there are some materialist positions you find more appealing than others. What sorts of considerations might inspire a full-blown conversion?




Bryan: As I understand the conceivability and knowledge arguments, they are arguments against the (metaphysical) supervenience of phenomenal properties on microphysical properties. So if successful, they establish that there are nonphysical properties (i.e. properties not supervening on microphysical properties), but they don't establish anything about nonphysical particulars. As for the metaphysics of particulars and properties in general, my views here are complicated by a sort of Carnapian deflationism about particulars -- see "Ontological Indeterminacy" (Powerpoint) for some of this.

Robert: A terminological point: I take property dualism to be roughly the view that both physical and nonphysical properties are instantiated, and to be neutral whether there are nonphysical particulars. On this understanding, property dualism is compatible with (and probably weaker than) substance dualism. So when I argue for property dualism, I'm not arguing against substance dualism. If there are instantiated nonphysical properties, then they are instantiated either by physical particulars or by nonphysical particulars. For the reasons given above, the anti-materialist arguments that I give are neutral as to the disjuncts of this disjunction. Maybe there are some further considerations that settle the issue between them (e.g. the considerations you allude to), but speaking for myself, I don't think I have conclusive arguments for either disjunct.

Pete: I can't think of any first-person data that would falsify my view, for obvious reasons. I think the sort of considerations it would take to establish materialism in the face of these arguments would be more philosophical, showing that some premise of the argument (e.g. the conceivability premise or a conceivability-possibility premise) is false. Now I've thought a lot about a considerations of this sort, put forward by very smart people, and haven't been convinced by them, so at least as a psychological prediction, I suspect that it's unlikely that I'll be converted. But certainly I think that any philosophical position ought to be at least tested against arbitrary considerations of this sort.

As for what sort of materialism I find appealing: certainly a type-F "Russellian" materialism, grounding consciousness in the intrinsic nature of the microphysical. But embracing that sort of view wouldn't really be a change of mind. As for other sorts, I suppose the materialist views I have the most sympathy with are those that appeal to phenomenal concepts and judgments: either (i) a type-A view that makes the case that all we need to explain is our judgments about consciousness, and that these judgments can be explained physically, or (ii) a type-B view that explains the epistemic gap in terms of special features of phenomenal concepts. Again, having thought about views of this sort quite a lot, I doubt that I'll be embracing them any time soon, but I think that they're definitely worth thinking about. In any case I'm all in favor of seeing new forms of materialism developed, and see how things stand in light of them.

Ignacio Prado

I think the dispute between Dr. Chalmers and Dennett could be productively understood as going even deeper than what data (i.e., first or third-person) need to be accounted for in a successful theory of consciousness. I think the dispute is somewhat meta-philosophical; it is over what it is in virtue of which we have access to "first-person data" to begin with.

Take a typical explanandum for a theory of consciousness:

(1)I have an experience of a certain tone, which my linguistic community calls “Middle C,” which has a distinct kind of subjective character.

(1) is a phenomenon that needs to be explained by our theory of consciousness. Both Dennett and Dr. Chalmers agree on this. The fundamental question I see as dividing them is what it is in virtue of which we have access to (1). The question can be raised not only for (1) itself, but for the whole category of phenomena of which (1) is an instance. In this case, the category would be the subjective/inner/qualitative character of sensory perception.

The traditional empiricist answer was that we have access to this subjective character by virtue of something like brute, pre-theoretical “acquaintance.” Our access to this experience is not conceptually or theoretically mediated. I believe Dennett would take Dr. Chalmers to be (at least implicitly) wedded to this picture of our access to the explanandum for a theory of consciousness.

Dennett, by contrast, is part of the Sellarsian tradition that understands our access to inner episodes as mediated by the conceptual role they play in a certain theoretical understanding of ourselves. To simplify drastically, we posit the “inner” nature of sensory perception to better explain our overt behavior and utterances, which are theoretically basic. Because our access to these episodes is theoretically mediate, better scientific theory can, in a sense, change the explanandum. Learning about attentional or change blindness can, for example, change our view about how much information about the environment we are given in sensory perception (and, by extension, change our view of how full or rich with detail our subjective experience is).

Understood this way, the debate between Dennett and Dr. Chalmers might then be understood as about the epistemological status of the “intuitions” we have about consciousness. For Dennett, those intuitions are largely an artifact of our current theoretical situation. As we deveop better theory, we will have better intuitions. For example, the intuition that the subjective character of sensory perception cannot be physically explained (i.e., that there is an explanatory gap between science and phenomenology) will be part of what goes away. For Dr. Chalmers, by contrast, the intuitions we have about consciousness constitute the nature of the explanandum in a much more absolute way. They set the conditions of adequacy on successful explanation. Rather than transform our notion of the explanandum, a theory of consciousness will, if successful, show us how what we currently take to be mysterious, the place of the phenomenal properties given to us in introspection within the physical world, fits in together elegantly with with the fundamental physical properties described by natural science.

Vadim Vasilyev

Dear David,

May be the crucial point here is Dennett's idea of seemingness. He repeats everywhere that it seems to us that we have some private conscious states. In fact, he treats this seemingness as a kind of explanandum. Talking about "seeming" he simply tries to use a neutral term and so to avoid any unsupported ontological conclusions. If so, his philosophy may be interpreted as a response to the "hard problem": he is to show why our seemingness of having conscious states (or simply our conscious states - I think, Searle is right in his identifying seemingness and reality in mental area, but it doesn't mean yet we know what kind of reality they have) arises from the brain. Only after giving such explanation we'd be able to say what consciousness really is. May be the whole point of Dennett is that we shouldn't decide that before investigating the brain functions. And if we see finally that every possible statement about our conscious states can be explained by the brain functions (as you accept too talking about paradox found by Elitzur), only then can we say that our belief there was something unexplainable from the "public" point of view in our conscious states was wrong, and that in THIS sense such states were illusionary.

Lion Kimbro


I hope to one day see the complete physical account by science of how it is that we talk about being consciousness. I strongly believe we will see it. But I strongly doubt it will convince me that is no consciousness.

It will not convince me any more, than my Buddhist friend's insistence that I don't actually exist.

If the whole thing is an illusion, there's still something that's being fooled.

The comments to this entry are closed.