Abstract. The following is an email interchange that took place between Dan Dennett and myself in the period 14^th to 28^th June, 2001. The discussion tries to clarify some essential features of the "heterophenomenology" developed in his book Consciousness Explained (1996), and how this differs from a form of "critical phenomenology" implicit in my own book Understanding Consciousness (2000), and developed in my edited Investigating Phenomenal Consciousness: new methodologies and maps (2000). The departure point for the discussion is a paper posted on Dan’s website that summarises a related debate between Dan, David Chalmers and Alvin Goldman (Dennett, 2001). To make the discussion easier to follow, the multiple embeddings have been removed (restoring the sequence in which the comments were written). I have also corrected a few typos and grammatical errors. However, the text of the emails remains exactly the same.

In Round 1, I suggest that scientific investigations of consciousness are better described as a form of "critical phenomenology" that accepts conscious experiences to be real rather than as a "heterophenomenology" which remains neutral about or denies their existence. Dan replies that I have misunderstood his position - he doesn’t deny that conscious experiences exist. Conscious experiences just don’t have the first-person phenomenal properties that they are commonly thought to have and, in his view, science remains neutral about the nature of such properties.

In Round 2, I agree with Dan that science initially remains neutral about how to understand the nature of conscious experiences. Nevertheless, the phenomenology of consciousness provides the data that scientists are trying to understand. A better understanding of data does not, in general, make the data disappear. I also ask, "if you remove the phenomena from phenomenal consciousness, in what sense is whatever remains "consciousness"? And, if one removes all the phenomenal content from what one takes consciousness to be, doesn’t this amount to a denial of the existence of "consciousness" in any ordinary sense of this term? Dan’s reply likens beliefs in phenomenal properties to the belief in evil spirits causing disease. He has no doubts that diseases such as whooping cough and tuberculosis are real, but this doesn’t require him to believe in evil spirits. And, what’s left, once one removes phenomenal properties, is what a zombie and a so-called conscious person have in common: a given set of functional properties that enable them to carry out the tasks we normally think of as conscious.

In Round 3, I summarise our similarities and differences. We agree that first-person reports are not incorrigible and that third-person information may throw light on how to interpret them. We also agree that first-person reports are reports of "something", although we disagree about the nature of that something. I suggest that Dan is sceptical about first-person reports rather than heterophenomenologically "neutral" (e.g. when he likens belief in phenomenal properties to belief in evil spirits). While we agree that science is likely to deepen our understanding of consciousness, I repeat that, unlike the replacement of old theories by better theories, a deeper understanding of phenomena does not in general replace the phenomena themselves. Rather than third-person data replacing first-person reports, the former are required to make sense of the latter, making their relationship complementary and mutually irreducible. In fact, there are many cases where science takes the reality of first-person phenomenology seriously, for example in the extensive literature on pain and its alleviation. If this can’t be squeezed into an exclusively third-person view of science, then we will just have to adjust our view of science - something that a "critical phenomenology" achieves at little cost. At the time of this editing, Dan has not replied.

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Reference. Dennett, D. (2001) The fantasy of first-person science.

http://ase.tufts.edu/cogstud/pubpage.htm

On 14 June Max Velmans wrote:

Dear Dan

R1.1 Thanks for letting me have a look at your interesting paper and for your invitation to comment. There are many things that I could say about it, but rather than take too much time in an email, I will just append a few thoughts relating to your challenge to Chalmers and Goldman at the end of your paper. You write:

R1.2 Let's deal with the challenge to Alvin Goldman first. I agree with you that the heterophenomenological method describes the approach taken by cognitive science studies of consciousness pretty well. Most scientists would accept that reports of experience are not incorrigible, and that there are cases where third-person investigations cast genuine doubt on beliefs about one's own first-person experiences (as in the case of inattentional blindness that you cite). There are even cases, easily reproduced in the laboratory where subjects themselves are not sure that they have experienced anything, for example with threshold stimuli. Given this, there are good reasons for remaining neutral (at least in the first-instance) about the veridical nature of first-person reports. But all this is pretty standard, and your real aim, I think, is not to tell cognitive scientists how to do their work. Your real aim is to construe scientific studies of consciousness in a way that is consistent with your deeper philosophical claim about the nature of consciousness - that it doesn't really exist (although it seems to exist). N'est ce pas?

R1.3 Given that it wouldn't be enough (for your position) to show that cognitive scientists SOMETIMES have doubts about the accuracy of subjective reports, your claim must be that heterophenomenology describes what scientists believe about subjective experiences even in clear cases where subjects themselves have no doubts about what they experience. Obvious examples would be where the stimuli produced simple, but relatively intense experiences such as bright lights, loud sounds, intense pains and so on.

R1.4 For consistency, neutrality about the reality of subjective experience would also have to apply to the experimenters' OWN experiences, for example in situations where the experimenters present themselves with the same stimuli that they have presented to subjects, and produce similar subjective reports.

R1.5 Do cognitive scientists who are cautious about the veridical nature of reports of experience in ambiguous cases, threshold cases etc., remain dubious about the reality of experience and the accuracy of subjective reports even in such clear cases, and even when the experiences are their own? I very much doubt it - although I have no doubt that, for consistency, you would do so yourself. Still - I guess that the only way to tell for sure is to do a head count, as this is a psychological question (about what scientists happen to believe), not a philosophical question, or a question about what scientists OUGHT to believe.

R1.6 During the behaviourist years the routine denial of conscious states was certainly adopted as a "badge of science," so one might have found it difficult to get psychologists to admit to the existence of any conscious experiences, clear or not. Of course they didn't admit to the existence of mind or mental processes either - that only changed with the emergence of cog sci. I would also agree that in the early days most cognitive scientists remained wary of referring to consciousness - with some eminent exceptions, e.g George Miller in his 1962 book The Science of Mental Life and George Mandler in his 1975 book Mind and Emotion. I give a fairly detailed history of all this in ch4 of my Understanding Consciousness. However, the zeitgeist has changed. For many years psychology was defined as "the study of behaviour". Now, the scientific affairs board of the British Psychological Society defines psychology as "the study of behaviour and experience." There is also a BPS section titled "The Consciousness and Experiential Psychology Section" that is devoted to systematising the study of conscious experience, and similar bodies (such as ASSC and The Center for The Study of Consciousness in Arizona) exist, as you know, in the US. It is worth noting that this interest in consciousness re-emerged after the subfields of cognitive science were well established. That is, psychology already had well established fields for investigating mental functioning using third-person methods in perception, learning, attention, memory and so on. So my first question to you is:

Q1. Why, if they retained doubts about the existence of consciousness, did psychologists redefine their field as the "study of behaviour and experience"; and why did they form professional bodies devoted to the study of consciousness?

R1.7 I guess that your answer to this could be that heterophenomenology describes what scientists actually do, irrespective of their beliefs about whether subjects really have conscious experiences. This would save your claim about heterophenomenology being an accurate description of cog sci. method, although you would have to abandon the view that all right-minded cognitive scientists support your claims about the non-existence of consciousness. However, if you do go this route I want to ask you a second question - this time about the method:

Q2. What distinguishes heterophenomenology as a method from "critical phenomenology" as a method?

R1.8 By "critical phenomenology", I mean an investigative method that accepts the reality of first-person experience, but which also accepts the need for cautious interpretation of subjective reports of those experiences, the potential relevance of third-person data to understanding experiences and so on. I have introduced the broad outlines of such an approach in my 1991 BBS target article - arguing that first- and third-person accounts of the mind are complementary and mutually irreducible. On this view both first- and third-person perspectives provide useful, but corrigible data about the nature of mind, and one uses the usual methods of triangulation, converging sources of evidence and so on to reach conclusions, decide between theories etc. I work some of this out in more depth in Understanding Consciousness. This first-person, third-person complementarity was also very much the approach of scientist involved in an international symposium on this very subject that I organised in the US at the Fetzer Institute in 1996 (see my edited Investigating Phenomenal Consciousness: New methodologies and maps, John Benjamins, 2000). Indeed, I would claim that most psychologists adopt this approach.

R1.9 Note that I have reversed your challenge to Chalmers. Your challenge was: " to name a single experiment (in good repute) which in any way violates or transcends the heterophenomenological method."

R1.10 My challenge to you is to name a single experiment (in good repute) which in any way violates or transcends the "critical phenomenological" method.

R1.11 My confident bet is that you can't, for the simple reason that the only thing that distinguishes heterophenomenology from a "critical phenomenology" is the belief, in the latter case, that what is being investigated is real. If you agree, then my third question to you is this:

Q3. Given that there is no methodological difference between heterophenomenology and critical phenomenology, but only the latter adopts the common sense belief that at least some conscious experiences are real, and that experimenters who study consciousness are investigating what they say they are investigating, why should we prefer heterophenomenology?

Looking forward to your response.

With best wishes

Max

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On 19 June Dan Dennett wrote:

Dear Max, I'm glad you wrote your comments, since it confirms a hunch of mine: you really have misunderstood my position. I'll put some reactions below.

Reply to R1.2: NO. Not at all. That "IT" doesn't really exist? What do you mean by "it"? That Cartesian glow doesn't exist? Of course it doesn't. That the Cartesian Theater doesn't exist? Yes. That consciousness doesn't exist? NO. My view is consciousness is QUITE DIFFERENT from what people think it is, but it does exist (witness the little story about the zoo, pp 43-45 of CE, especially page 45--I don't see what more I could have done to drive home this point, but it was obviously not enough, since an astute reader like you missed it).

Reply to R1.3: NO. This is NOT my point. My point is that people have a varying ideology about the NATURE of their phenomenology that is dubious and has nothing to do with how bright or vivid an experience is. That whole ideology must be bracketed for neutrality. Thus Block thinks there is property of "phenomenality" that some of his mental states have. He MIGHT be right, but he also might be wrong; so we bracket that belief of his--it has no privilege. The bracketing has nothing to do with faint or penumbral cases. A zombie would have all the difficulties of a non-zombie in telling whether or not a faint experience [or pseudo-experience, in you insist] counted as F or G; what we bracket is the question of whether or not there is a difference between a zombie and a non-zombie.

Reply to R1.5: NOTICE: I am not dubious about the reality of experience. How many times do I have to say that? I am dubious--neutral, more aptly--about the NATURE of that reality. OF COURSE there are "animals" in the zoo. I'm just as radical about the nature of the great big unmistakable elephants as about the nature of the stick insects (or is that actually a stick or a leaf?). So you miss the point. This is not what the head count should concern itself with.

Reply to R1.6 Again, you've missed the point. I do not claim that cognitive scientists "retain doubts about the existence of consciousness"; I claim that they use methods that are scrupulously non-committal about the truth (and more important, the reference) of subjects' reports.

Reply to R1.8 Well, I don't know exactly what you mean by "accepts the reality of first person experience". It you mean "accepts the reality of experience", we're on the same team; if you mean something like "accepts that the reality of experience involves an ineliminable, irreducible, unstudiable first-person-ness [whatever it takes to distinguish a zombie from a non-zombie], then we aren't.

For instance, could a robot have first person experiences? Under what conditions? I say yes, and sketch what those conditions are. If you say NEVER or say that one could never tell by any scientific test, we disagree.

Reply to R1.11, Q3: FALSE. (M.V explanatory note - in this one word comment, Dan is taking issue with my suggestion that critical phenomenology assumes conscious experience to be real, whereas heterophenomenology denies the existence of conscious experience)

I hope this clarifies my position. I also hope you'll now see how little stands in the way of your joining me in heterophenomenology. (Or we could call it critical phenomenology, but you have to be explicit about neutrality on zombies.)

Dan

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On 21 June Max Velmans wrote:

Dear Dan

R2.1 I was very interested to get your response to my comments. If I have misunderstood your position I can only apologise - people often do that with my own work (in spite of my best efforts to be clear) and its very frustrating. But, on looking at what you say closely, I'm not sure yet that I really have misunderstood your position. Let's try to get to the bottom of it!

R2.2 As I said in my earlier email, I take your real aim to be "to construe scientific studies of consciousness in a way that is consistent with your deeper philosophical claim about the nature of consciousness - that it doesn't really exist (although it seems to exist)." What I mean by "it" of course is what people usually mean by the term "consciousness," i.e. "phenomenal consciousness," including qualia such as the bright appearance of the sun, the smell of new mown grass, the sharp pain produced by a bee sting and so on.

R2.3 I think that you are denying that such qualia really exist and I think that you make this pretty clear for example in the following extract from your 1994 chapter in the book by Revonsuo and Kampinnen (I use this quote to characterise your views in UC):

"Philosophers have adopted various names for the things in the beholder (or properties of the beholder) that have been supposed to provide a safe home for the colors and the rest of the properties that have been banished from the external world by the triumphs of physics: raw feels, phenomenal qualities, intrinsic properties of conscious experiences, the qualitative content of mental states, and, of course, qualia, the term I use. There are subtle differences in how these terms have been defined, but I am going to ride roughshod over them. I DENY THAT THERE ARE ANY SUCH PROPERTIES. BUT I AGREE WHOLEHEARTEDLY THAT THERE SEEM TO BE." (my caps - Dennett, 1994, p129) (I notice on looking again that you say much the same on p372 of CE).

R2.4 Now, I agree with you that "a Cartesian glow" misdescribes such experiences, and they certainly do not require a "Cartesian theatre" in the brain for their display (given the neuroscientific evidence does anyone believe this these days?). However, "a critical phenomenology" nevertheless ACCEPTS THAT THE EXPERIENCES THEMSELVES DO EXIST AND THAT THE TASK OF PHENOMENOLOGY IS TO EXPLORE THEIR PROPERTIES. I don't mean phenomenology with a big P by the way (following Husserl). I am talking about the usual thing that happens in say, studies of sensation and perception involving the development of a descriptive system appropriate to the phenomenological terrain, followed by a categorical system (e.g. of minimal discriminable differences). This might then be followed by investigation of a range of related questions such as "What is the relation of the phenomenology to human information processing?" "In what way is the phenomenology dependent on sensory physiology?" "How well do experiences represent the things that they are experiences of?" and so on (I develop this and much else to do with characterising phenomenology with a small p in UC).

R2.5 Your write "My view is consciousness is QUITE DIFFERENT from what people think it is, but it does exist." My question to you is:

Q4: If consciousness is quite different from what people think it is, but it does exist, then what is it that exists? Or to put it another way, if you remove the phenomena from phenomenal consciousness, in what sense is whatever remains "consciousness"?

R2.6 I know, of course, that you have devoted a lot of thought to what is left once you get rid of the qualia, and I quote some of your arguments relating to this in my book. Colour qualia for example resolve into discriminative states that dispose humans to express verbal judgements that allude to the colour of various things.

R2.7 I have some problems with your arguments however. So maybe the simplest thing to do is to attach an extract from my book (see end). You can then assess whether my interpretation of your position is fair and, if you wish, address some of the problems that I raise.

R2.8 But let's suppose for the moment that I am right about your intent: to remove the qualia or phenomenal content from consciousness (in order to make it amenable to a pure 3rd person account). If so I want to ask this question:

Q5: If you remove all the phenomenal content from what you take consciousness to be, doesn't this AMOUNT to a denial of the existence of "consciousness" in any ORDINARY sense of this term?

R2.9 If it does, then I would repeat my point (Q1 above) that many scientists (working on consciousness) would not agree with you. For many investigators of consciousness, ITS PHENOMENOLOGY PROVIDES A SOURCE OF PRIMARY PSYCHOLOGICAL DATA. And these conscious psychological phenomena don't disappear once one has explained their neural or other structural/functional causes and correlates. As I argue in various places in my work, causes and correlates are not ontological identities (see e.g. Goodbye to Reductionism, 1998 on-line, or UC ch3).

R2.10 You also write above, that my stress on what cognitive scientist believe about the existence of consciousness "misses the point" and that your real point is that cognitive scientists "are scrupulously non-committal about the truth (and more important, the reference) of subjects' reports."

R2.11 But I am not sure what point I have missed here. I have already agreed with you that many scientists are cautious about relying only on subjective reports or accepting the accuracy of subjective reports in unclear cases. However I don't think that many scientists are non-committal about the REFERENCE of subjective reports (that certainly wouldn't be true for Jerome Singer, Ben Libet, Francisco Varela, John Kihlstrom, Tony Marcel, and Jeffrey Gray - to name a few). On the contrary, in most experimental situations that require subjective reports, psychologists assume that subjects are honestly trying to report WHAT THEY EXPERIENCE as accurately as they can. In short they engage in a form of critical phenomenology.

R2.12 And that just takes us straight back to Q2 and Q3 above. Given that there is no methodological advantage to heterophenomenology, why prefer this to a more common sense, critical phenomenology?

Re the zombies - let's just hang fire on these for now (I do have quite a bit about machine consciousness etc in my book, but would like to sort out the above first).

Not quite ready to join your team yet.

Best

Max

On 24 June Dan Dennett wrote:

I will embed some comments in your ROUND 2 below. We're getting closer. Good.

Reply to R2.2: But this won't do, as I keep trying to explain to people. I myself have no qualms about the bright appearance of the sun, the smell of new mown grass, etc., but I do have qualms about calling these "qualia" since philosophers then go on to insist that qualia (as exemplified, one presumes, by these cases) have properties that THESE CASES MAY WELL NOT HAVE. For me, it is as if you said something like "you are denying the existence of disease, including possession by evil spirits such as influenza, whooping cough and tuberculosis." I don't deny tuberculosis, etc. I deny that it is a case of possession by evil spirits

Reply to R2.3 (note from MV - Here Dan accepts that the quote I take from CE represents his position fairly and expands it as follows):

Reply to R2.5, Q4: It is what a zombie and a so-called conscious person have in common: the rather strikingly marked set of functionally definable categories that I metaphorically describe in terms of fame in the brain.

Reply to R2.6: That is not all; you're ignoring here all that I have to say about, e.g., the affective role of color (e.g., CE, pp395ff). See also in the Revonsuo volume.

Reply to R2.8, Q5: No. Unless you insist on building into all ordinary senses of the term the idea of some "intrinsic" features. Cf. my remarks on the "vis" of dollars in my Cognition paper. Perhaps the ordinary American concept of a dollar insists that in addition to all its merely functional powers (its exchangeability for francs, pounds sterling, etc.) it has its intrinsic value. But if so, so much the worse for the ordinary American concept of a dollar. Right? I AM insisting on NEUTRALITY with regard to the "phenomenality" of consciousness precisely because that is a tendentious term, like the claim that dollars have vis.

Reply to R2.9: Some anthropologists studying Feenomanism may, in fact, be true believers--Feenomanists. But if they do their job right, they don't let their faith interfere with their science and they study Feenomanism straight. Many scientists studying consciousness may in fact believe in intrinsic properties of conscious states (e.g., in qualia as philosophers have defined them, or in "raw feels," or "phenomenality" or in some other feature of conscious states that distinguishes conscious folks (according to their creed) from mere zombies. But if they do their science right (and I think in fact that they do), this belief of theirs (those who have it) is NOT used in an attempt to justify ANY deflection from heterophenomenology, which is appropriately neutral on these issues. My point is that heterophenomenology allows the scientists to vary quite radically in their ideology while their science is conducted in neutral terms. It is not Chalmers (or you) who is neutral. It is the heterophenomenologist.

Reply to R2.11: It all depends on what you try to pack into "what they experience". I myself can happily accept this claim--because FOR ME, "what they experience" doesn't have the definition or connotations (e.g., "intrinsic" properties) that it does for others. And having just spent quite a few hours discussing these issues with Tony Marcel, I think you should put at least a "(?)" after his name. We're pretty much on the same page, in spite of our differences in emphasis. We can't ask Cisco any more, alas, but as I have often said about his work, it is ideologically generous but methodologically scrupulous.

Best wishes,

Dan

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On 28 June Max Velmans wrote:

Dear Dan

R3.1 Let’s try to bring this to some form of conclusion. If I read our interchange so far correctly there are some central issues on which we agree. We agree that first-person reports are not incorrigible, and we also agree that, in psychological science, third-person information may throw light on how to interpret first-person reports. We also agree that first-person reports are reports of "something". However, we disagree about the nature of that something and about how accurate and useful first-person reports can be.

R3.2 You argue in favour of a heterophenomenology that is "neutral" about the accuracy of first-person reports. On closer examination of what you have written above, however, you are not really "neutral" about the accuracy of first-person reports at all. On the contrary, you are downright sceptical! Although you maintain above that you have never denied the existence of consciousness, it is clear that you fervently deny the existence of what ordinary people (and many scientist) mean by consciousness, i.e. it is your aim to eliminate "phenomenal consciousness." Indeed, you liken people’s ordinary beliefs about and reports of their conscious experiences to primitive superstitions (similar to beliefs in evil spirits) that are destined to be replaced in some future, exalted science, by entirely "functional zombie" accounts of mind.

R3.3 You write above,

I don’t think though that this quite expresses what is at issue between us in the right way. I argue for a "critical phenomenology" in which first-person reports can sometimes be accurate accounts of experience, and would defend the common sense view that what it is like to have those experiences can, in the initial instance, only be determined from a first-person report. The experiences are primary psychological data, and the first-person reports are initial descriptions of that data (expressed in ordinary language). As an investigator, it would not be my aim to eliminate or reduce the data (e.g. to behavioural dispositions). But that does not make the reports and the experiences on which they depend unstudiable. On the contrary, the whole aim of a critical phenomenology is to subject the reports and the experiences on which they depend to systematic study. I agree with you that our understanding of consciousness is likely to deepen as studies proceed. But I see no good reason to believe that an understanding of the causes and correlates of consciousness, its function, its relation to that which is not conscious, etc., would somehow make the conscious phenomenology disappear. I accept that, in science, it is common for prescientific THEORIES to be replaced without remainder by more advanced theories. But a deeper understanding of PHENOMENA does not in general replace the phenomena themselves. In any case, the relation of first- to third-person information isn’t one of "muddled subjective" to "clear-minded objective". While first-person reports are not incorrigible, neither are third-person reports. While third-person information can influence the proper interpretation of first-person information, first-person information may also be needed to guide and interpret third-person information. For example, without asking a subject when they become aware of a stimulus, how could one ever determine the precise neural changes required to make a transition from a preconscious to a conscious state? In these and many other ways, first- and third-person accounts (of experiences and brain states/functions) are complementary and mutually irreducible. In my book, a complete understanding of mind requires both.

R3.4 I am guessing here, but I assume that your primary motivation for your full-blooded attack on first-person phenomenal consciousness is to defend the completeness of an entirely third-person, reductionist view of the world. If facts about consciousness cannot be translated without loss into "functional zombie" facts, then an entirely third-person account of the mind (such as that provided by computational functionalism) remains incomplete.

R3.5 This isn’t of course the first time in the history of science when it has proved difficult to squeeze the phenomena under investigation into an existing theory or even a prevailing worldview. I accept that sometimes it just needs a bit more effort - but at other times it just can’t be done. And if it can’t be done, I would argue that the rational, scientific response is to expand or modify existing theory, investigative methods, and even the prevailing worldview, to accommodate the phenomena.

R3.6 I think that currently there is a substantial body of scientific opinion in favour of the latter approach (that was the point of my Q1 to you above). Francisco V, for example, was one of the pioneers of an expanded consciousness science. You describe his work as "ideologically generous but methodologically scrupulous." I agree with you that it is methodologically scrupulous. However much of the work of his Paris group involved a systematic, structured form of first-person (introspective) investigation (see for example his 1999 edited collection in JCS The View from Within). In these investigations, both the subjects AND the experimenters believed that they were carrying out systematic first-person research. You might not find it completely impossible to translate all this into heterophenomenology. But if you have a look at the procedures adopted by the Paris group I think that you would find it very difficult - and you would wind up with a description of what was going on that would be less elegant, and lower in ecological validity than that given by the subjects and researchers themselves. So, coming back to your original challenge to Dave Chalmers, if you admit that these experiments are methodologically scrupulous, they would count as experiments that "transcend the heterophenomenological method" (to anyone that isn't a born again heterophenomenologist).

R3.7 I should stress of course that the work of the Paris group is a development of Phenomenology with a big P (following Husserl), and my own defence of "critical phenomenology" refers just to phenomenology with a small p. A "critical phenomenology" might include Phenomenology (in so far as its methodology is scrupulous) but the former (small p version) only requires one to accept that conscious phenomenology really exists, that first-person reports provide the first route to descriptions of it, and then remains open (neutral) about the best way to investigate it in more detail, to understand it in more depth (without eliminating it) and so on.

R3.8 Although this isn’t reductive, it seems to me to combine a perfectly good, open-minded science with common sense. And, scanning the above, I’m not sure that you have really addressed my challenge to name an experiment on consciousness (in good repute) whose methodology can’t be described in this way.

R3.9 If you can’t, then all that you have left on the table I think are the arguments that rely on analogous reductions that have taken place in the history of science, e.g. where you argue that accounts of phenomenal consciousness will be replaced without remainder in the same way that "evil spirits" have now been replaced as descriptions or causes of influenza, tuberculosis and whooping cough (the same fate that awaited jimjams, and heebie-jeebies). I have examined many of the reductionist analogies in the consciousness literature (UC chs.3 & 5) but found them to be unpersuasive (and usually false). I don’t have time to elaborate on all that here - but are you really suggesting that experienced pain for example is just a prescientific superstition? If so, it’s odd that medical science has devoted so much effort to its alleviation. I’ve checked. Over the period 1966 to 1998, the Medline database lists over 148,000 publications on pain and its alleviation (in spite of it being a paradigm case of a private, subjective, mental event within philosophy of mind). And by the way - while pain researchers have developed many ways to measure the subjective experience of pain (verbal rating scales, numerical rating scales, visual analogue scales and questionnaires such as the McGill Pain Questionnaire) at the present time no valid "objective" measure of pain experience (in terms of a physiological index) exists.

I rest my case.

With best wishes

Max

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It is generally agreed that colours, sounds and so on are not inherent properties of the physical world. Rather, such "qualia" are produced in our experience by the action of physical energies on our perceptual systems. Such experiences don’t exist without experiencers. But few would go so far as to deny the existence of conscious experiences altogether! Dennett, however, tries to do just that:

"Philosophers have adopted various names for the things in the beholder (or properties of the beholder) that have been supposed to provide a safe home for the colors and the rest of the properties that have been banished from the external world by the triumphs of physics: raw feels, phenomenal qualities, intrinsic properties of conscious experiences, the qualitative content of mental states, and, of course, qualia, the term I use. There are subtle differences in how these terms have been defined, but I am going to ride roughshod over them. I deny that there are any such properties. But I agree wholeheartedly that there seem to be." (Dennett, 1994, p129)

"What science has actually shown us is just that light-reflecting properties of objects ... cause creatures to go into various discriminative states ... These discriminative states of observer’s brains have various primary properties (their mechanistic properties due to their connections, the excitation states of their elements, and so forth), and in virtue of these primary properties, they ... have secondary, merely dispositional properties. In human creatures with language, for instance, these discriminative states often eventually dispose the creatures to express verbal judgements alluding to the color of various things. The semantics of these statements makes it clear what colors supposedly are: reflective properties of the surfaces of objects or of transparent volumes ... And that is just what colors are in fact ... Do not our internal discriminative states also have some special intrinsic properties, the subjective, private, ineffable properties that constitute the way things look to us (sound to us, smell to us, and so forth)? No. The dispositional properties of those discriminative states already suffice to explain all the effects: the effects on both peripheral behavior (saying "Red!", stepping on the brake, and so forth) and internal behavior (judging "Red!", seeing something as red, reacting with uneasiness or displeasure if red things upset one). Any additional qualitative properties or qualia would thus have no positive role to play in any explanations, nor are they somehow vouchsafed to us directly in intuition. Qualitative properties that are intrinsically conscious are a myth, an artifact of misguided theorizing, not anything given pretheoretically." (Ibid, p130).

Dennett tries to explode this "myth" we all engage in, by examining situations in which humans clearly seem to use qualia to carry out tasks, and then showing that the same task can be carried out without qualia by a robot. Suppose, for example, that one is asked to compare billiard-table-felt-green and Granny-Smith-apple-green in the "mind’s eye" in order to decide which has the paler hue. We seem, in such instances, to retrieve information from memory that enables us to compare one subjective experience directly with another, on the basis of which we make our response. But a robot fitted with a TV camera and suitable colour coding equipment (of the kind available off the shelf) could perform the same discrimination without using representations that are themselves coloured, and in actual fact, Dennett suggests, we do the same:

"Nothing red, white, or blue happens in your brain when you conjure up an American flag, but no doubt something happens that has three physical variable clusters associated with it - one for red, one for white, and one for blue, and it is by some mechanical comparison of the values of those variables with stored values of the same variables in memory that you come to be furnished with an opinion about the relative shades of the seen and remembered colors." (Ibid, p136)

While the brain no doubt performs such comparisons via different physical processes to those of the robot, according to Dennett, there is no reason to claim any less phenomenal content for the discriminative states of the robot than for discriminative states of the brain. The "qualia" of consciousness have no real existence, either in humans or in machines!

To the watchful reader, the sleight-of-hand in this argument should be clear. Note that Dennett tries to eliminate colour qualia in four steps:

1) he translates first-person accounts of what it is like to experience colour "qualia" (the experience of Granny-Smith-apple-green, etc) into third-person accounts of how systems might perform tasks (how they might achieve colour discrimination, colour naming, stop on red, and so on)

2) he shows how the task might be performed by brains or machines without the use of representations that are themselves coloured

3) he concludes that "qualia" are not needed for functional explanations

4) he concludes that "qualia" do not exist.

Step 1 is fundamental to computational functionalism (in its normal eliminative and reductionist forms). If one cannot reduce first-person accounts of what it is like to experience something into third-person accounts of how systems function without leaving something important out, these versions of functionalism cannot get off the ground. Yet it seems obvious that something important is left out! Once one strips conscious qualia away from accounts of how a system processes information or of how they are disposed to behave, one has removed all reference to how things appear from a first-person perspective. Consequently, these accounts no longer tell one anything about what it is like to experience something! For example, it might be possible to specify the precise functional correlates of sharp pains, shooting pains and burning pains in information processing terms. But unless one had actually experienced such pains one would not know how these feel. Overt behaviour or dispositions to behave are even less informative, as there are no rigid links connecting experience with behaviour. If I am in pain, I might be disposed to be stoic or to make a big fuss without altering the pain I feel. Conversely, I might respond in exactly the same way to pains that are qualitatively distinct (see the discussion of behaviourism and the reasons for its demise in psychology in chapter 4).

The absence of any rigid link between "qualia" and behaviour is even clearer in machines. As Dennett notes, qualia are actually irrelevant to accounts of how machines might discriminate between colours. His robot-with-TV-camera, for example, might actually experience Granny-Smith-apple-green as billiard-table-felt-green (and vice-versa) or as pale blue versus dark blue, or it might have no experiences whatsoever. Provided that it translates electromagnetic energies into internal physical variables that suffice for machine discrimination, its behaviour might remain indistinguishable from that of a human being whichever is the case. But the converse of this is that machine discrimination alone tells us nothing about machine experience - and certainly nothing about human experience!

Given that Dennett’s stated intention is to explain conscious experience, and not just how brains and machines perform tasks (his 1991 book is called Consciousness Explained) this is a rather large omission - to which we return below.

But first let us consider steps 2, 3 and 4. Step 2 is easily justified. There is little doubt that accounts can be given of brain or machine functioning in physical or information processing terms that make no appeal to the "qualia" of conscious experiences. Indeed, viewed from a third-person perspective, it is difficult to see how conscious qualia could affect the behaviour of neurons or silicon chips (as the physical world appears causally closed). And, if one examines the experimental literature regarding the relation of conscious qualia to human information processing with care, one comes to the same conclusion (see chapters 4 and 9, and Velmans 1991a).

Step 3 (that qualia are not needed for functional explanations) then follows from step 2. However, step 4 does not follow from step 3. The primary evidence for conscious experience in humans is first-person evidence. Computational functionalism (in its eliminative and reductionist forms) tries to show that mental terms denote nothing more than causal relations (intervening between input and output) in functioning systems, which can be specified in entirely third-person, information-processing terms. If such causal relationships can be fully specified without reference to the qualia of consciousness, one can conclude that conscious qualia are irrelevant or superfluous to such third-person accounts. But it does not follow that conscious qualia have no useful place in "first-person" accounts, nor that they do not exist.

End of extract from UC

Dennett, D. (2001) The fantasy of first-person science.

http://ase.tufts.edu/cogstud/pubpage.htm

Varela, F and Shear, J. (eds) (1999) The View From Within. Journal of Consciousness Studies, Volume 6: Feb/March.

Velmans, M. (2000) Understanding Consciousness, London: Routledge/Psychology Press.

Velmans, M (ed) (2000) Investigating Phenomenal Consciousness: New methodologies and maps, Amsterdam: John Benjamins.