Daniel Dennett

The time has come to talk about Daniel Dennett. He is the self-proclaimed captain of the "A" team, the king of the reductive materialists (he declared David Chalmers the captain of the "B" team). His manifesto, 1991's "Consciousness Explained", is an absolute must-read for anyone interested in this field. It is extremely clearly written, persuasive, and loaded with style, a dry wit, and fascinating facts and findings relating to the study of the human mind. One simply can not discuss philosophy of mind in any useful way without having some response to Daniel Dennett and his arguments. At the same time, one must occasionally rise above his characterization of his opponents as fearful, reactionary, silly people desperately clinging to their vanities about the human soul. It should come as no surprise at this point that I think Dennett is wrong, at least in some of his conclusions. It may come as something of a surprise, however, in this sharply divided field of inquiry, that I think that nearly all of what Dennett says in his book is right.

Dennett has no use for so-called qualophiles like myself. This is part I disagree with. But the vast bulk of the book is concerned not with arguments against qualia themselves, but against the idea that there is some central executive in the mind, some special module (either anatomically or functionally defined) that constitutes "my consciousness", such that sensory inputs are distinctly pre-conscious on one side of the module, and memories or motor outputs are distinctly post-conscious on the other side of it. Instead, Dennett proposes what he calls the Multiple Drafts Model, according to which there are lots of modules (or agents, or, more colorfully, demons), lots of versions or portions of versions of sensory inputs, and it never exactly comes together in any one place or at any one time in the brain to constitute "my field of consciousness right now". Dennett often describes the mind as more of a pandemonium (literally, "demons all over") than a bureaucracy. He makes many persuasive arguments against the idea of a single central executive in the mind, and powerfully challenges our intuitions about our selfhood. But then he makes an abrupt right turn, concluding that therefore, qualia do not exist in any sense whatsoever.

According to Dennett's hypothesis, among the specialized modules in the brain there is a verbalizer, a narrative spinner (some people call this module or something like it the monkey mind; I think of it as the chatterbox). The chatterbox produces words, and words are very potent or sticky tags in memory. They are not merely easy to grab hold of, they are downright magnetic. They are velcro. The output of this particular module seduces us into thinking that what it does, its narrative, is "what I was thinking" or "what I was experiencing" because when we wonder what we were experiencing or thinking, its report leaps to answer. The products of this chatterbox constitute what we think of as the "self". Dennett says we spin a self as automatically as spiders spin webs or beavers build dams. This very property makes this chatterbox powerful, and gives its narrative strong influence in guiding future action, thought and experience, but it is a mistake to therefore declare it to be the Central Executive.

Dennett likes to say that what we call the "self" is really just a "center of narrative gravity", and as such, merely a useful fiction. In the same way, an automobile engine may have a center of gravity, and that center of gravity may move around within the engine as it runs. The center of gravity of the engine is perfectly real in some sense - one could locate it as precisely as one wanted to - but in another sense it does not really exist. It performs no work. It is what I might call a may-be-seen-as kind of thing, not a really-there kind of thing. Dennett thinks that the self is the center of narrative gravity in exactly this sense.

Dennett makes a great deal of the difficulty of distinguishing clearly between experiencing something as such-and-such, and judging it to be such-and-such. In response to an imaginary qualophile, Dennett says, "You seem to think there's a difference between thinking (judging, deciding, being of the heartfelt opinion that) something seems pink to you and something really seeming pink to you [emphasis his]. But there is no difference. There is no such phenomenon as really seeming - over and above the phenomenon of judging in one way or another that something is the case." (p. 364) In a way he is right - it is a fascinating and fruitful problem. In his book, Dennett gives many examples that serve to undermine our faith that we really do experience what we think we experience, and there are many others that are not in his book.

Dennett says to imagine that you enter a room with pop art wallpaper; specifically, a repeating pattern of portraits of Marilyn Monroe. Now, we only have even reasonably high-resolution vision in our fovea, the portion of our field of vision directly in front. The fovea is surprisingly narrow. We compensate with saccades - unnoticably quick eye movements. Nevertheless, as Dennett says, we could not possibly actually see all the details of all the Marilyns in the room in the time it takes us to form the certain impression of being in a room with hundreds of perfectly crisp, distinct portraits of Marilyn. I'll let Dennett himself take it from here:

Now, is it possible that the brain takes one of its high-resolution foveal views of Marilyn and reproduces it, as if by photocopying, across an internal mapping of the expanse of wall? That is the only way the high-resolution details you used to identify Marilyn could "get into the background" at all, since parafoveal vision is not sharp enough to provide it by itself. I suppose it is possible in principle, but the brain almost certainly does not go to the trouble of doing that filling in! Having identified a single Marilyn, and having received no information to the effect that the other blobs are not Marilyns, it jumps to the conclusion that the rest are Marilyns, and labels the whole region "more Marilyns" without any further rendering of Marilyn at all.

Of course it does not seem that way to you. It seems to you as if you are actually seeing hundreds of identical Marilyns. And in one sense you are: there are, indeed, hundreds of identical Marilyns out there on the wall, and you're seeing them. What is not the case, however, is that there are hundreds of identical Marilyns represented in your brain. Your brain just somehow represents that there are hundreds of identical Marilyns, and no matter how vivid your impression is that you see all that detail, the detail is in the world, not in your head. And no figment [Dennett's term for the metaphorical "paint" used to depict scenes in the Cartesian Theater - figmentary pigment] gets used up in rendering the seeming, for the seeming isn't rendered at all, not even as a bit-map.

The point here is that while we may think we see the Marilyns on the wall, and we may think that we have a qualitative experience to that effect (just like our qualitative experience of seeing red), this is almost certainly not the case. Instead, what is happening is that we have inferred, or judged that there are Marilyns all over the wall, and we have a very definite, certain feeling that we actually see these Marilyns. Sometimes we think we directly experience things that are right in front of our faces, but really we just conclude that we have experienced them. Our inability to tell the difference is intended to make qualophiles like myself uneasy. I think I am being fair to Dennett to characterize his claim as follows: we think that our direct experience is mysterious, but often it can be shown pretty straightforwardly that when you think you are directly experiencing something, really you are just holding onto one end of a string the other end of which you presume to be tied to this mysterious experiencing. Given this common and easily demonstrated confusion, it is most likely that all purported "direct experience" is like this, that all we have is a handful of strings. We never directly experience anything; we just judge ourselves to have done so.

Dennett also discusses the blind spot in our visual field. There are simple experiments that demonstrate that a surprisingly large chunk of what we normally think of as our field of vision is not actually part of our field of vision at all. We simply can not see with the part of our retina that is missing because of where the optic nerve leaves the eyeball. The natural, naive question is, why don't I notice the blind spot? The equally natural, and equally naive explanation is that the brain compensates by "filling in" the blind spot, guessing or remembering what should be seen in that region of the visual field, and painting (applying more figment) that pattern or color on the stage set in the Cartesian Theater.

Dennett is quite emphatic that nothing of the sort happens. There is no Cartesian Theater, so no filling in is necessary. There is no such thing as seeing directly, there is only concluding, so once you conclude (or guess, or remember) what should be in the blind spot, you are done. There is no inner visual field, so there is no need for inner paint (figment), or inner bit maps. We do not notice the blindness because "since the brain has no precedent of getting information from that gap of the retina, it has not developed any epistemically hungry agencies demanding to be fed from that region".

There are also easily performed experiments that demonstrate change blindness: the phenomenon whereby you can be shown a photograph, and then shown an altered version of the same photograph and be unable to spot the differences. Often the differences can be pretty dramatic, far more drastic than you might think could possibly go unnoticed. Once again, you think you really see the first photo in a lot more detail than you actually do, but it turns out that instead you merely judged that you had seen it. You nailed down a few major details, decided that you had seen it, and that was good enough. Your confidence that you really see something is misplaced - you only think you see.

Dennett describes experiments in which people were fitted with goggles that turned their entire field of vision upside down. While "comically helpless" at first, soon the subjects were able to ski and bicycle through city traffic while wearing the goggles. Dennett says, ". . . the natural (but misguided) question to ask is this: Have they adapted by turning their experiential world back right side up, or by getting used to their experiential world being upside down?" Dennett holds that this is simply a wrong question, and in fact, the more completely adapted the subjects of the experiment were, the more they reported that the question had no good answer. The experience of the visual field is inseparable from your use of it, your cognitive interpretation of it.

Imagine a room. Do not do it by reference to a real room with which you are familiar, make up a room you have never actually seen. Do so in as much detail as you can. Take as long as you like. Got it? Now - is there crown molding around the ceiling? If so, what kind? What is the millwork of the baseboards like, if it has any? What kind of latches are there on the windows? If you are like most people, you thought you visualized the room in pretty specific detail, but when asked pointed questions about it, you are distinctly aware of making up your answers on the fly. You didn't really see the room in your mind's eye in as much detail as you thought you did.

These are very interesting examples and point to an important problem in our conception of the distinction between experiencing and judging. Often when we think we perceive a whole lot of detail directly, what is really going on is that we have cognitive access to a whole bunch of detail on demand, if we (or any of the agents, or as Dennett calls them, demons, that comprise us) ask for it, accompanied by a fuzzy sense of directly perceiving the detail "directly". But Dennett is wrong to jump from that to the conclusion that we never really experience anything, that its all just judging. The circle of experience may be smaller than we usually think, or it may have less distinct boundaries, but we can not plausibly shrink it to a point, or out of existence altogether.

I agree that it is impossible to draw a clear distinction between experience and judgment, but this is because judgment is itself a sort of structured experience. There is no naive experience: our interpretations are part and parcel of our perceptions. It is interesting that Dennett never clearly and simply defines "judgment". Computers do not know, judge, believe, or think anything, any more than the display over the elevator doors knows that the elevator is on the 15th floor. All they do is push electrons around. Even calling some electrons 0 and others 1 is projection on our part, a sort of anthropomorphism. It seems as though I see all the Marilyns; Dennett says no, I merely judge that I see them. He is right to force us to ask ourselves how much we really know about the difference. He is wrong to think that the answer makes either one of them less mysterious, or more amenable to a reductive, materialist explanation.

Some of this echos my previous discussion about the impossibility of distinguishing between data and algorithm. It is kind of like the difference between having a map showing a place you need to drive to, and having a list of directions to that place. You can follow the directions, turning where they say to turn, without ever forming any overall conception of where you are or where you are going. If the directions are sufficiently elaborate, they can even tell you how to get back on track if you make a wrong turn. You can simply follow them, and never "put it all together" into any bird's eye, directional sense of where you are. Could it not be the case that even when we do have a sense of where we are, say, in the middle of our home town, that sense is an illusion, and all we really have is a really good set of directions for how to get any place we might need to go? When it comes right down to it, is there any real difference between "directly" perceiving something in all its detail on one hand, and having on-demand answers to any questions you might pose about that thing on the other? Could it be the case that we think that we have an immediate, all-at-once conception or perception of something, but all we really have is an algorithmic process that is capable of answering questions about that something really quickly, a just-in-time reality generator?

If I think I have a conception of something, say, a soldering iron, could it turn out that really there is nothing but an algorithm, a cognitive module in my head with specific answers to any question I could have about the soldering iron? At any point, in any situation, the algorithmic module would produce the correct response to any question about the soldering iron in that situation. How to use it, what it feels like, its dangers, its potential misuse, its utility for scratching my name with its tip into the enamel paint on my refrigerator. Such a module would serve as a just-in-time reality generator with regard to any experience I might have involving the soldering iron. It would consist of a bundle of expectations of sensory inputs and appropriate motor outputs regarding the soldering iron. To use the computer terminology, as long as the soldering iron module presented the correct API to the rest of the mind, wouldn't the mind be "fooled" into thinking that it had a qualitative idea of the soldering iron, when all it really had was a long list of instructions mapping input to output? How do I know I have a concept of the soldering iron beyond the ability to form a whole bunch of judgments about the soldering iron, given the difficulty of distinguishing between being conscious of something and merely making judgments about it? Is it possible that after all, I simply do not have any holistic, all-at-once conception or perception of the soldering iron? And is there really any difference between the two ways of characterizing our cognitions regarding soldering irons?

No, It is not possible, and yes, there is a difference. When I see the soldering iron, I really do see it. If I look at a white wall with three black circles painted on it, I see them all before me. Chalmers once asked, what is it like to see a square? What is it like to look at the well-known Necker cube? For that matter, what is it like to see the word "cat"? There is judgment, inference, interpretation, and cognition here. There are associations, memories, connotations, and all the rest of the cognitive baggage. There is also experience. The mystery here is how they all relate; to what extent they are really the same thing; and to the extent that they are the same thing, what gives rise to the intuition that they are different in the first place; how some things that take place in the mind are more experience than judgment or cognition, and other things are more judgment or cognition than pure experience. What is the sense that I see all the Marilyns if not itself a quale?

The difficulty with cleanly distinguishing between "directly" perceiving something and merely judging it to be a certain way, (while having specialized modules for answering questions about it) is not limited to visual perception or perception at all, in the usual narrow sense. Nor is it limited to perception of the outside world. The same kinds of ambiguity exist with regard to our understanding of our own minds. I believe the sun will rise tomorrow. Do I really hold this single belief, or is it just a huge bundle of expectations and algorithms, each pertaining to specific situations or types of situations that I might find myself in? Any of the unitary things we naturally posit in our minds (models, images, memories, beliefs) could have some component at least of such a bundle of algorithms, or agents. For any such thing, what is its API to the rest of the system, really? How much can we really say about how it implements that API? Maybe I just infer somehow that I have a belief that the sun will rise tomorrow, but that "belief" is not nearly the short little statement written down somewhere that it seems to be. The articulation of the belief could, as Dennett suggests of all of our articulations, be the result of some kind of consensus hammered out by lots of demons or agents. Nevertheless, the sense that I have such a belief is real, and unitary, even if the belief itself is not. Frankly, I don't know right now what a belief is, or what a judgment is. Until someone convincingly gives an account of these things, it rings a little hollow to dismiss qualia as "merely" complexes of judgments or beliefs.

When I walk into a room I may not consciously notice each of the fire sprinkler heads mounted on the ceiling. Do I see them? Even after a good look around, I would likely flunk if quizzed about their exact number or arrangement, even though I feel as though I have seen the whole room, in all its detail. Dennett says that this feeling is illusory. I choose to say that the sprinkler heads do not intrude, as it were, on my consciousness because insofar as I care, there is nothing about them that should surprise, interest, or concern me. I've noticed them - if I had never seen or heard of a sprinkler head before, within a very few seconds upon entering the room they would command my full attention - but I've written them off at a relatively low level of perception. At some point in my life, I've noticed them, thought about them, stared at them during dull staff meetings, convinced myself that I more or less understand them - in effect, built a sprinkler head recognition agent. When I enter and scan a room, this agent is awake, active, but quiescent. Nevertheless, it contributes in some admittedly poorly understood way (by me at least) to where I'm at, consciously.

I have an overall sense that I see and comprehend the room. If I had the mind of a dog, I might still have a sense that I see and comprehend the room, even though the sprinkler heads never registered at all on any level whatsoever. My dog mind has no sprinkler head recognition agents. Nor does it have any particular curiosity about details it does not recognize. (no epistemically hungry agencies, to use Dennett's term). My human sense that I see the room and my satisfaction that I understand it are quite different than the dog-mind's sense, even though in the end we are both satisfied that we see and understand it. I see and understand insofar as I care, have ever cared, or could imagine caring about whatever it is I am looking at.

My own speculation is that the epistemically hungry agencies are conscious. Some are relatively permanent, some are constituted by constantly shifting, waxing and waning coalitions of other agents. The sprinkler head recognition agent feels quite clever, that it has made a really creative leap here - it has never seen these particular sprinkler heads, in this light, from this angle, in this context, yet it declared them to be sprinkler heads. It is always thinking about sprinkler heads, and always looking for them. It is always trying to see sprinkler heads.

So how do these "agents" stack? How do "lower" ones get incorporated into "higher" ones until they all get subsumed by the one at the top, the tip of the pyramid, the consciousness that is me? On this last question, Dennett is right. There probably is no tip of the pyramid.

When I look at my living room, I seem to have a certain sense that I see it before me in all its colorful, varied entirety. What is the connection between this "certain sense" and actually seeing it? My sense of seeing it is not an opaque ability to answer questions - I don't feed demands for information into a black box and get information back. It may well be, as Dennett says, that a pandemonium of demons (couch demon, rug demon, lots of other, more abstract demons concerned with context and associations) in some way contribute to my overall comprehension. Moreover, it may well be the case that this "overall comprehension" just is the pandemonium itself, not some master demon, or some Central Meaner. Maybe later, if asked what was going through my mind, the "I was comprehending my living room" demon may be overruled by the "I was worrying about my property taxes" demon. Maybe I was comprehending the living room, but come to think if it, I was paying special attention to the drapes. Or was I? Maybe any of the demons could make a good case that they were the whole point, the where-it-all-comes-together. From each demon's point of view, it is right. We have lots of seats of consciousness in our minds.

If all of the demons are conscious to some degree or another, if that term is to have any meaning at all, then there are some consciousnesses that never manifest themselves distinctly in any kind of a master narrative of "what was going through my mind". Perhaps some of them are evolutionary dead ends in the pandemonic Darwinian jungle that is my mind. Maybe some of them don't even nudge any of the others above the level of random noise or jitter, even though, for their possibly quite brief existence, they were conscious. There was something it was like to be them.

At one point (pp. 132-133) Dennett speaks of the impossibility of nailing down what you are conscious of and when you are conscious of it. He rightly points out that in many situations there is no good answer to the questions of exactly what you are conscious of and when:

We might classify the Multiple Drafts model, then, as first-person operationalism, for it brusquely denies the possibility in principle of consciousness of a stimulus in the absence of the subject's belief in that consciousness.

Opposition to this operationalism appeals, as usual, to possible facts beyond the ken of the operationalist's test, but now the operationalist is the subject himself, so the objection backfires: "Just because you can't tell, by your preferred ways, whether or not you were conscious of x, that doesn't mean you weren't. Maybe you were conscious of x but just can't find any evidence for it!" Does anyone, on reflection, really want to say that? Putative facts about consciousness that swim out of reach of both "outside" and "inside" observers are strange facts indeed.

Yes, yes they are, but there it is. There are, in fact, consciousnesses within my skull that swim out of reach of any demon or collection of demons that might generate utterances or typings about what "I" am or were conscious of at any particular time. This should not seem odd, frankly, even to a reductive materialist. However you define consciousness, assuming you find any use for the term whatsoever, why is it impossible, or even unlikely, that the submodules and sub-submodules that comprise my mind might themselves individually qualify as conscious? And if they do qualify as conscious, they might not all necessarily be patched into any larger consciousness, or feed into any higher level of consciousness. Of course the ones that do are probably more interesting to us, and how exactly they feed in is a subject for further speculation. And perhaps some of them spin off on their own until asked a certain way, or until the right kind of slot opens up for them to contribute their bit. Recall Dennett's compelling image of constantly shifting coalitions of demons. So it should not seem silly or bizarre that, in some sense, I was conscious of a stimulus but didn't know it. Or perhaps the "I" that reports on such things did not know it, or know it in the right way.

Dennett is right - the single continuous self is illusory, a virtual machine implemented on a parallel architecture. He is wrong, however, in thinking that this explains consciousness or dissolves its mystery. Far from it.

Go back up to the main page