:: Article

Thinking fish & zombie caterpillars

Michael Tye interviewed by Richard Marshall.

Michael Tye is the jumpin’ jack flashman of philosophy of mind, always updating his zap mind with rigorous brooding on the nature of phenomenal consciousness. To do this he has to consider a whole bunch of things – including inverted earths, whether swamp things have eyes, how chinese sounds to the chinese, the beliefs of fish, one eyed zombie caterpillars, camouflaged moths, orgasms, the planet Vulcan and the difference between Keith Richards hallucinating a tomatoe and him hallucinating a unicorn. He writes his books to catch his thoughts as they shoot on by. All in all, he’s a funky swell.

3:AM: What made you become a philosopher? Was it really because you just wanted to avoid the lab work of physics? Were there seeds planted way before?

Michael Tye: I went up to Oxford as an undergraduate to study physics. I chose Oxford over Cambridge at the urging of my school physics teacher who was an Oxford man. When I arrived, I found out that, as a physics student, I was expected to spend one day a week in the laboratory. This seemed to me extremely unappealing not only because it would interfere with my social life but also because the practical side of physics was, to my mind, deadly dull. Happily, I discovered that there was a new undergraduate degree — physics and philosophy — that combined theoretical physics with philosophical issues in the foundations of physics as well as pure philosophy. For this degree no practical work was required.

I asked to transfer into physics and philosophy and, in response to my request, I was told to go away and write an essay on truth with particular reference to the Austin/Strawson debate on the topic. I had never heard of Austin or Strawson at the time, but this I duly did with the help of the college library and, presumably after having not embarrassed myself too badly, I was admitted into the physics and philosophy degree program.

I did not find myself especially interested in the philosophical half of the degree until late in my final undergraduate year. This was due largely to the fact that my college philosophy tutor, who shall remain nameless here, chose not to speak during our tutorials except in the most perfunctory way, preferring instead to stare into the fireplace while puffing on a cigar. (To my knowledge, during his entire career he published just a single essay – on the location of sounds.) I recall his intense dislike of things American. “’Functionalism’,” he would later say to me in an exaggerated, slow and disdainful manner, wrinkling his nose as he did so, “I suppose that is an American word.”

What lured me into philosophy was the sense-datum theory. I did not believe the theory but I found myself very intrigued by it and largely as a result of the writings of Ayer and Austin, I decided to rethink my original plan, which was to do a theoretical physics doctorate. So, that is how I became a philosopher.

3:AM: You are a naturalist philosopher and take science to be very important. So why shouldn’t we just leave it to the scientists to find out about the mind and consciousness? What can philosophers add?

MT: I take philosophers to ask very general questions about the world and ourselves, and also about our relationship to the world and one another through our senses and our social interactions. Philosophers, in my view, should develop their theories in such a way as to respect as much as possible both the latest and best scientific theorising about the world as well as the vast store of wisdom contained in what might be called our “commonsense, everyday theory of things” (dubbed by Sellars the “manifest image”).

One way to capture what philosophers of mind, as opposed to scientists interested in the mind, are (or at least should be) trying to do is as follows. Scientists focused on the mind ask: How does this mental faculty work? How does memory work, for example? How are mental images generated? How does shape recognition take place? These questions are ‘how’ questions. They pertain to actual creatures of one sort or another (for example, human beings). They do not pertain to non-actual, possible creatures. And they can be understood, in different instances, to ask for the neurophysiological underpinnings of the appropriate mental faculty or for the computational underpinnings or simply for the more basic psychological components that generate the faculty in the relevant range of creatures.

Philosophers of mind ask: What is such-and such a mental faculty or state? What is it to remember something, for example? What is it to recognise a shape? What is pain? These ‘what’ questions should be understood to ask what is common to all actual and possible creatures that have the relevant mental property or state (remembering something, recognising a shape, etc) in virtue of which they have the property or state. In this way, they are asking about the general nature of the faculty or state.

So, neurophysiology, scientific psychology and artificial intelligence do not directly offer answers to the questions philosophy of mind asks. The philosopher of mind should respect the answers given by scientists to the appropriate ‘how’ questions while insisting that ‘what’ questions remain about which there can be reasonable disagreement – questions whose answers require theorising at a more general level than is found in the individual sciences. Of course with the appropriate theorising, it may be concluded that one of the sciences in particular — for example, neurophysiology — not only provides an account of how the given mental faculties or states are generated in actual creatures (of their realisation in those creatures) but also can supply an account of the general nature of the faculties or states. However, this conclusion is not one that the neurophysiologist, qua neurophysiologist, is in any position to reach. It is not shown to be true directly by neurophysiology and it may reasonably be denied while accepting all that the neurophysiogical account has to say.

3:AM: So what does your theory say the mind and consciousness is?

MT: I am best known for my theory of the nature of phenomenal consciousness. Let me focus on that. I’ll begin by saying a few uncontroversial things about phenomenal consciousness. Of our conscious mental states, some are inherently conscious. That is to say, some of our mental states cannot fail to be conscious. For each such mental state, there is a subjective perspective that goes along with it. This perspective is conferred upon the subject simply by his or her undergoing the mental state. It is captured in everyday language by talk of ‘what it is like’. There is something it is like subjectively to feel pain, to smell vomit, to taste chocolate, to feel elated. Furthermore, what it is like to undergo one inherently conscious mental state can be compared with what it is like to undergo another. For example, what it is like to experience bright red is subjectively more similar to what it is like to experience bright orange than to what it is like to experience dark green.

Mental states that are inherently conscious are standardly said to be phenomenally conscious by philosophers. ‘Phenomenal consciousness’, then, is a feature of mental states. As to which mental states are phenomenally conscious, one not very informative answer is that they are experiences. More helpfully, we can classify the relevant states into at least the following categories: (1) Perceptual experiences, for example, experiences of the sort involved in seeing green, hearing loud trumpets, tasting liquorice, smelling the sea air, running one’s fingers over sandpaper.
 (2) Bodily sensations, for example, feeling a twinge of pain, feeling an itch, feeling hungry, having a stomach ache, feeling hot, feeling dizzy. Think here also of experiences such as those present during orgasm or while running flat-out. (3) Felt reactions or passions or emotions, for example, feeling delight, lust, fear, love, feeling grief, jealousy, regret.
(4) Felt moods, for example, feeling happy, depressed, calm, bored, tense, miserable.

As a way of getting at the basic features of my view of phenomenal consciousness, take the case of visual experience. Right now, as you are reading this, you are subject to a visual experience. You are aware of the computer screen before you as well as various other things and a whole host of properties of these items. Suppose I ask you whether you can also be aware of your visual experience. I think that the natural answer to this question is ‘No’. Those who, like me, think that this is the right answer say that experience is transparent to us. When we try to become aware of our visual experiences by introspecting, we seem to ‘see’ right through them so that all we are really aware of is what is outside. Of course, you are aware via introspection that you are having a visual experience. You are aware that you aren’t blind. But you aren’t aware of the experience.

Not only are you not aware of your visual experience, you can’t attend to it. You can switch your attention from the computer screen to the flowerpot on its right, say, but you can’t switch your attention from the screen to your experience. The experience isn’t something on which you can focus your attention at all. All you are really aware of, all you can really attend to, is stuff outside you or at least stuff that is presented to you as being outside you. (The stuff might not really be outside, for it might be that you are undergoing an extended, extremely vivid hallucination.)

What’s the relationship between the stuff outside – the stuff you experience – and your experience? I say that it is stuff represented by the experience. What I mean by this is that it is stuff the experience ‘tells’ you is out there. This has an important consequence. If all you really have access to is stuff outside, then the subjective character of your experience – how it ‘feels’ to you – has got to be understood in terms of the outside stuff, however strange that may initially seem. On this view, what makes two experiences subjectively the same is that they represent the same stuff (roughly) and what makes two experiences subjectively different is that they represent different stuff.

Of course, not everything mental that represents anything is an experience. Think, for example, of the visual system. Vision is highly complex but it begins with representations of what is going on at the retina, representations of light intensity and wavelength. These early representations aren’t conscious at all. What representations have to do to get to be experiences, on my view, is that they have to arise at the right level in the information processing. They have to be available to cognitive processes in the right sort of way. They have to be appropriately ‘poised’. Your visual experience of the computer screen before you and its properties is the evidential basis for your belief that there is a computer screen ahead and a whole host of related beliefs. This evidential basis does not itself involve the application of concepts. Experiences are non-conceptual states given to us by nature, not requiring learning. They are (largely) fixed by our phylogenetic nature. Given how human beings are built, they automatically undergo a certain range of experiences. Given how bats are built, they automatically undergo another.

The idea, then, is (roughly) that experiences are suitably cognitively poised mental states that nonconceptually represent the world. Their phenomenal character – what it is like to undergo them – is given by what they represent (or more carefully, on my current view, by the cluster of properties they represent as being possessed by things out in the world (or in the body, as in the case of bodily sensations)).

This view of experience has come to be called ‘representationalism’. I first advocated a (slightly different) version of it in my book Ten Problems of Consciousness in 1995.

3:AM: A couple of really fun ideas that help get a grip on some of your key ideas are the idea of an Inverted Earth and the idea of the Swampman. I think many readers will have had the thought that maybe on another planet what I take to be blue they take as yellow and vice versa. And that if a creature was born without a history but with my implanted mental states we’d wonder what their mental states were really. What are the key things these stories are supposed to help reveal? Is it that without a teleological account of mind – i.e. one that tracks the purpose of minds – we don’t get anywhere?

MT: Inverted Earth is an imaginary planet, on which things have complementary colours to the colours of their counterparts on Earth. The sky is yellow, grass is red, ripe tomatoes are green, and so on. The inhabitants of Inverted Earth undergo psychological attitudes and experiences with inverted representational contents relative to those of people on Earth. They think that the sky is yellow, see that grass is red, etc. However, they call the sky ‘blue’, grass ‘green’, ripe tomatoes ‘red’, etc just as we do. Indeed, in all respects consistent with the alterations just described, Inverted Earth is as much like Earth as possible.

In Ned Block’s original version of the tale, one night while you are asleep, a team of alien scientists insert colour-inverting lenses in your eyes and take you to Inverted Earth, where you are substituted for your Inverted Earth twin or doppelganger. Upon awakening, you are aware of no difference, since the inverting lenses neutralise the inverted colours. You think that you are still where you were before. What it is like for you when you see the sky or anything else is just what it was like on earth.

But after enough time has passed, after you have become sufficiently embedded in the language and physical environment of Inverted Earth, your experiences and beliefs will come to represent just what the locals’ experiences and beliefs do. You will come to believe that the sky is yellow, for example, just as they do. Similarly, according to Block, you will come to have a visual experience that represents the sky as yellow. For the experiential state you now undergo, as you view the sky, is the one that, in you, now is normally caused by and tracks yellow things. So, the later you will come to be subject to inner states that are representationally inverted relative to the inner states of the earlier you, while the phenomenal aspects of your experiences will remain unchanged. It follows supposedly that my view of phenomenal consciousness is mistaken.

One simple reply that the representationalist can make with respect to this objection is to deny that there really is any change in normal tracking with respect to colour, at least as far as your experiences go. “Normal”, after all, has both teleological and nonteleological senses. If what an experience normally tracks is what nature designed it to track, what it has as its biological purpose to track, then shifting environments from Earth to Inverted Earth will make no difference to normal tracking and hence no difference to what your experiences represent. The sensory state that nature designed in your species to track blue in the setting in which your species evolved will continue to do just that even if through time, on Inverted Earth, in that alien environment, it is usually caused in you by looking at yellow things. So, the sky on Inverted Earth will look blue to you even though you call it ‘yellow’ no matter how long you spend there.

On this view, our senses are akin to instruments and our sensory experiences are akin to states of those instruments. Think, for example, of the pointer positions on a speedometer. When the pointer points to ‘60mph’ on the speedometer, it represents that the car is going at 60 mph. This is a consequence of its original design and this is what it will continue to represent even if the speedometer is used for some other purpose. Likewise for our visual experiences.

The suggestion that tracking is telological in character, at least for the case of basic experiences, goes naturally with the plausible view, mentioned earlier, that states like feeling pain or having a visual sensation of red are phylogenetically fixed. On this view, through learning we can change our beliefs, our thoughts, our judgements, but not our basic experiences. Having acquired the concept microscope, say, we can come to see something as a microscope, but we do not need concepts simply to see. Once the receptor cells are matured, it suffices to open the eyes. No learning or training is involved. Basic visual experiences are nonconceptual. Small children see pretty much what the rest of us see. They differ from us in how they see things, in what they see things as. They do not see that the kettle is boiling, the house as being dilapidated, the computer as malfunctioning.

This reply to the Inverted Earth objection, tempting though it is, faces a problem. It entails that accidental replicas of actual sentient creatures lack all experiences. Consider, for example, the case of the swamp creature formed by the chemical reaction that takes place in a swamp after a lightning bolt hits a log there. Swampman, as he is usually known, is an accidental molecule-by-molecule duplicate of some actual human-being, but he has no evolutionary history. On a cladistic conception of species, Swampman is not human. Indeed, lacking any evolutionary history, he belongs to no species at all. His inner states play no teleological role. Nature did not design any of them to do anything. So, if phenomenal character is understood in a teleo-representational way, then Swampman has no experiences. This according to some philosophers, is unacceptable.

The first representationalist about experience to embrace the supposedly unpalateable conclusion was Fred Dretske (in 1995). I now think that Dretske was right. The question of what to say about the case of Swampman is not restricted to the case of experiences. Ruth Millikan has said that Swampman does not have eyes, since an eye is an organ whose presence is to be explained in terms of descent from creatures whose fitness was increased in certain specific ways by the operation of that organ. Swampman’s eye-like structures are present merely by chance, and so do not count as eyes. The implications are far-reaching: Swampman doesn’t see anything, assuming seeing constitutively involves using eyes, doesn’t walk, assuming that walking involves use of legs, and legs, like eyes, are individuated historically; and so on.

The surprising character of this view can be diminished by noting that something just like an eye, but which is not an eye, can be as useful as an eye; and likewise for all the other features. Something just like a human, though not human, may be as loveable as a human, and as worthy of a place in our moral scheme. Likewise, something functionally just like an experience may get Swampman around as well even if it is not an experience. So, I am inclined simply to bite the bullet on the Swampman example.

3:AM: It seems that in the disputes between alternative accounts of how to handle alternative earth and Swampman, philosophers draw on intuitions about what would be natural for someone to say and think in these circumstances. But there’s evidence in x phi that suggests that a lot of self-reporting about introspected thoughts is false. So do you worry that cool arguments against Ned Block and Shoemaker et al might be sullied by errors (and theirs too)? Perhaps intuitions are just untrustworthy?

MT: No, I don’t worry. Intuitions are a bit like perceptual ‘seemings’. My belief that I am sitting at a table, drinking coffee is based on how things appear or seem to me. The appearances can, and do, sometimes lead me astray. But they form the basis for my perceptual beliefs about the world. Intuitions play a similar role in connection with philosophical reflection. Certain things seem to me obvious or undeniable and I then try to tailor my philosophical theories to fit or preserve those intuitions. Can they lead me astray?Yes, but so what?

In some cases, intuitions are, I think, influenced by prior philosophical commitments. For example, the intuition in the Swampman case that intrinsic duplicates must feel the same thing, so that my Swamp duplicate must feel just what I do, seems to me to come from a Cartesian, internalist picture of the mind. But then perceptual seemings are sometimes causally influenced by prior beliefs too. For example, how a Chinese speaker sounds to native Chinese speaker is very different from how it sounds to me. Knowledge of the meanings of Chinese words causally influences how the sound stream is segmented and this impacts how it appears or seems to the hearer.

As for xphi and self-reporting of introspected thoughts, my own view is that there is less here than meets the eye. Philosophers have often held a privileged access thesis with respect to conscious, occurrent thoughts to the effect that when introspection is working normally (as it should), thinkers can know what they are (presently) thinking just on the basis of introspection. This is not a thesis about past or remembered thoughts. It is not a thesis about knowledge of the species of a mental state (whether it is a desire or a belief, say). It is not a thesis to the effect that the final authority on what is going on in the mind is the person whose mind it is. To my knowledge, no xphi result shows that there is anything wrong with the privileged access thesis, understood as above.

3:AM: You think that qualia are the heart of the mind body problem. Some, like Dennett in his paper ‘Quining Qualia’ just deny qualia exist. Dennett calls them illusions – but the obvious question is what is it that they are supposed to be illusions of? Others like Richard Brown find that just an outrageous position. He thinks it’s obvious that qualia exist. So why is this so important to you and what’s your take on the matter? I think you agree with Alex Byrne that they ‘aint in the head’, but it seems hard for me to understand how they could be anywhere else if they are supposed to be understood as ontological and not epistemic? I guess that makes me kind of some sort of dualist, which isn’t very cool is it?

MT: The term ‘qualia’ is philosophically loaded. In one sense, it is obvious that qualia exist; for it is obvious that people have experiences and feelings and that there is something it is like for them to undergo such states. Often, however, when philosophers talk of qualia they have in mind more than this. According to one view, the subjective character of an experience – what it is like to undergo it – is a matter of the intrinsic, non-representational, introspectible features it possesses. I am opposed to this view. I deny that there are any such features. If I now introspect my experience of red, say, I don’t come across any features of the experience at all. I just come across the color red. And my experience of red is not itself red. Red is what my experience represents. Since I am aware of the subjective character of my experience – how it feels – when I introspect, it follows that the subjective character of an experience is to be understood in terms of the qualities the experience represents rather than the qualities it possesses.

As for Dennett, the most charitable way to read him is as holding that experiences themselves are dispositions to believe various things. So, there are no experiences or qualia, conceived of as non-epistemic, non-belief-laden entities. This view seems obviously mistaken but the alternative is to read Dennett as just denying that there are any such things as experiences and subjective character at all. And that is worse than obviously mistaken – it’s crazy. Hence, Block’s quip that that Dennett’s book, Consciousness Explained, should have been titled Consciousness Ignored.

Pages: 1 2

First published in 3:AM Magazine: Thursday, October 4th, 2012.