What is consciousness for?

In 2015 I was invited to write a short piece on consciousness for the magazine Aeon. The text now appears to be unavailable on Aeon, so I am reposting it here.

From the moment we wake we are bombarded with stimuli. Electromagnetic radiation floods our eyes, pressure waves hit our ears, surfaces press against our skins, molecules adhere to the membranes of our noses and tongues. Our sense organs react, sending nerve impulses to our brains, where they trigger waves of neural activity, which may culminate in motor commands to our muscles (shielding our eyes from the light, for example). But something else happens, too. We have conscious experiences. We see a bright light, hear a scream, feel the roughness of a surface. There is something it is like to detect the stimuli; each experience has a distinctive qualitative aspect — a quale in philosopher’s jargon (plural qualia). Such experiences constitute what we call consciousness. But what is consciousness for? What do qualia do?

This may seem an odd question. The answer, surely, is that qualia carry information about the world. A red visual sensation tells us there is something red present; an acrid smell tells us something is burning; a pain tells us our body is damaged. There’s a problem, however. For we could get this information without qualia. Engineers build robots with computer vision systems that can detect and classify colours, shapes, and movements with considerable accuracy. They don’t need to give the robots qualia. Indeed, sometimes we behave in a robotic way ourselves. Most drivers have had the experience of driving absentmindedly, without paying attention to the road. Yet during these spells we must still be taking in visual information or we would crash. Or consider blindsight, a condition discovered in the 1970s by the psychologist Nicholas Humphrey. Humphrey studied a macaque monkey, Helen, whose primary visual cortex had been surgically removed. By the usual tests Helen was blind, but Humphrey discovered that, with encouragement, she could detect a range of visual stimuli, and in time she was able to interact with her surroundings almost as if fully sighted. (See a video of Helen and read Humphrey’s report.) Blindsight has been discovered in humans too, and the patients confirm that, though they can accurately ‘guess’ shapes and colours, they have no conscious visual sensations.

It appears, then, that the brain can do the work of perception without qualia. So, again, what is consciousness for? In his 2011 book Soul Dust, Humphrey proposes a novel idea. He argues that consciousness enriches life. It doesn’t add information; it adds interests and goals. Qualia are wonderful, magical things, and conscious creatures enjoy having them. They relish their sensations, and this relish gives them a deeper interest in their own existence. They also project qualia onto their surroundings and take a deeper interest in them too; and they come to think of themselves as having a self, which is of great importance to them. These developments, Humphrey argues, have great survival value and explain why evolution equipped with us consciousness. (Watch Humphrey talking about these ideas.)

This may be just the change of perspective we need to understand consciousness. There’s a catch, however. For qualia are very strange things; they are utterly unlike any properties known to the physical sciences, and many philosophers argue that they are nonphysical. But there is good reason to think that everything that happens in the physical world has a physical cause. Since we are part of the physical world, this means that if qualia are nonphysical, they cannot affect us. Humphrey’s proposal threatens to be self-defeating. Qualia enrich life because they are magical; yet because they are magical they can’t affect us and enrich life!

There’s a possible way out of this, which Humphrey himself adopts. It involves another radical idea. Maybe qualia are a sort of illusion. Evolution couldn’t set it up so that brain states really have qualia, so it did the next best thing. It set things up so that they seem to have qualia when we attend to them (when we introspect). Consciousness is, as Humphrey puts it, a sort of inner magic show, in which brain states are the actors and introspection the audience.

This is a big pill to swallow, and even if you’ve gone along with the argument so far you will probably want to get off here. An obvious objection is that, when it comes to qualia, seeming is reality. If I seem to be having a sensation of red, then I’m having one. This looks like a knock-down objection, but maybe we can edge round it. Here’s the idea.

Cognitive science sees the mind as a representational system, a system that records information about the world in a sort of internal code and uses this information to guide behaviour. On this view, for us to be aware of anything, our brains must represent it. This goes not only for external properties accessed through the senses (which can be represented in a robotic, blindsighted way), but also for internal properties accessed through introspection. Even if our brain states did have qualia, our brains would have to represent these qualia in order for us to be aware of them. Unrepresented qualia would be no more to us than unheard sounds. But representations are not always accurate — sometimes our brains misrepresent things. Indeed our surroundings might be set up precisely to induce such misrepresentation. A prankster might use scenery and video projections to trick a person into thinking they were seeing things they weren’t. And maybe evolution has pulled a similar trick on us — setting up our internal landscape so that introspection represents it as illuminated with magical, nonphysical qualia. Of course, it doesn’t seem that qualia are an illusion, but it wouldn’t if evolution has done its work well.

This is counterintuitive, but is it more so than the view that consciousness does nothing? It is very plausible to think that consciousness transforms the lives of the creatures who possess it, but maybe it is a transformation that can be wrought only by trickery.

Originally published in Aeon online magazine, 25 June 2015.

Nothing but

Many people find physicalism an inhumane, philistine view. I wish I could dispel that idea. What underlies it, I suspect, is the ‘nothing but’ thought: If we are nothing but matter, then where is our specialness, our value, our subjectivity?

But why does it matter what we are made of? Suppose we were immaterial souls instead of physical beings. Would that make us special? Why? Couldn’t we still worry that we were nothing but soul stuff?

So where does our specialness come from? Perhaps our physical bodies are infused with a nonphysical essence that confers subjectivity and value? But that suggestion explains nothing at all. It’s just saying that are special because we possess an intrinsic specialness.

I think there’s a better way of looking at it. It’s not the stuff we’re made of that matters, nor some essence within it. It’s the way the stuff is organized. Is Michelangelo’s David ‘nothing but marble’? Yes; there’s no extra ingredient or special essence. But it’s marble shaped in a meaningful way by the hands of a great creative artist. And we are matter shaped in a meaningful way by billions of years of natural experimentation and selection.

It’s this billion-year heritage of natural design that has endowed us with the sensitivities and reactive dispositions that underpin our sense of value and subjectivity. We’re matter that nature has made special — and we’re beginning to understand how nature did it.

How to annihilate everything

Does reality get on your nerves? Do you sometimes wish there was nothing at all? Then this is the post for you! Read on, and I’ll show you how to prune your ontology down to nothing. It’s easy and won’t harm anyone or anything. Ready?

Let’s start by clearing out the attic. We’ll throw out abstract objects and universals, together with mathematical objects and structures. We’ll get rid of possible worlds too — the actual one is more than enough! And we can manage without God, can’t we? In fact, let’s get rid of everything supernatural while we’re at it.

It’s already feeling less stuffy. But we need to live more in the moment. Let’s let go of the past — and the future with it. Only the present moment exists.

We’ve made good progress. But scientists keep cluttering the place up with things we can’t even see. We’ll put a stop to that! We’ll be scientific anti-realists, at least as regards things we can’t see for ourselves.

That feels better. But there’s still a lot left. There’s the Earth and the solar system and all the visible universe. It’s too much. Let’s be idealists and put it all in our minds. But what sort of idealists? We could be transcendental idealists — sweep it all under the noumenal carpet and focus on our representations of it. But it would all still be there, taunting us with its unknowable reality. No, let’s do it properly and be empirical idealists, like Berkeley. There’s no material world at all; only ideas of it in our minds.

Now we’re getting somewhere! Let’s see — what have we got left? Just our minds and their contents and the present moment. But it still feels crowded. There are billions of minds here, each with its own set of perceptions and thoughts. What we need is solipsism — the powerful metaphysical kind. There aren’t any other minds; just this one here and its one set of ideas.

That’s better. No abstractions, no past, no future, no space, no matter, no other minds, only the momentary existence of this one self and its ideas. In fact, let’s get rid of the self as well. All that exists is this momentary bundle of thoughts and perceptions.

Right. We’re nearly there. Nothing exists beyond this mental moment right here and now. Do you want to take the last step? Are you ready to annihilate the whole of reality?

You are? OK. Get somewhere quiet. Close your eyes. Block your ears. Now, breathe gently, and just … let … your … mind … go … blank.

For the record

A little note on something that happened on Twitter. Yesterday I created a gender-swap image of myself with FaceApp. I liked it — it give me a different perspective on myself — and I posted it on Twitter. Some people liked it and no one complained. Later, one person (not themselves trans, I believe) wrote to say that they felt such images were disrespectful to trans women. They were polite and didn’t ask me to remove the image. However, I became concerned that some trans women might think I was mocking them, and I decided to delete the image, just in case. I didn’t do it because I felt bullied or because I was worried the image would harm me professionally, and I wouldn’t delete a post I felt strongly about. (If you scroll back through my Twitter feed, you’ll see that I have posted and robustly defended plenty of controversial opinions, especially about the nature of consciousness.)

Soon a host of people began attacking me for (as they saw it) caving in to the trans lobby. “BEND THE KNEE”, one well-known gender-critical tweep wrote. Others accused me of monetary motives for my action and suggested that my behaviour undermined my credentials as a philosopher. Some suggested that I wouldn’t have cared about mocking cis women and that I was supporting the patriarchy. One — bizarrely — called me a cuckold.

Well, that’s what happened. I’m going to take a break from Twitter for a while.

The phenomenal concept strategy is a worn-out band-aid

For a quarter of a century, the default physicalist response to arguments for property dualism has been the phenomenal concept strategy (PCS). The strategy turns on a claim about the nature of our phenomenal concepts — the concepts we employ when we attend to our current experiences and think about what they are like. There are many variants of the strategy, and the literature on it is large and technical, but the core idea is simple.

It’s this. Phenomenal concepts function as bare referential devices — demonstratives perhaps. They do not pick out their referents as properties that fit some physical description but latch onto them directly via the exercise of some mental capacity. Since we do not conceptualize phenomenal properties as physical ones, we can easily imagine them varying independently of the physical facts, and this accounts for the intuitions that drive the anti-physicalist arguments — intuitions about zombies, inverts, Mary, and so on. Yet, phenomenal properties might be physical ones all the same. The only dualism the anti-physicalist arguments establish is one of concepts, physical and phenomenal.

I don’t think the strategy works. For it does nothing to explain why we find phenomenal properties anomalous. After all, we employ direct referential devices all the time without generating any ontological worries. Imagine being in a chemistry lab and asking, “What’s this?” or “What sort of stuff is that?”, pointing to a substance or holding up a sample. We don’t conceive of the substance we’re referring to in any particular way — as, let’s say, an acid salt. And, I suppose, we could imagine the substance being removed while all the acid salts remain where they are. But if we are told on good authority that the substance is an acid salt, then we are satisfied. We wouldn’t typically experience any puzzlement as how it could be an acid salt, and we wouldn’t think it conceivable that the stuff we’re indicating could disappear while all the acid salts remained in place. If we were to feel any puzzlement on these matters, it would because of how the stuff looked and our background beliefs about what acid salts are like.

If the PCS were sound, then the same should be true of phenomenal properties. Gesturing inwards at a twinge of pain and asking “What’s this?”, should not generate any intuitions about the nature of the state picked out and we should have no difficulty in accepting that it is a physical one, if that’s what the science indicated.

But that doesn’t happen. Even if we’re thoroughly convinced that the brain has no nonphysical properties, we still feel puzzled by the situation. We still can’t understand how this twinge of pain could be a brain state, and we still have a strong inclination to think that there’s some extra feature present that is only contingently connected to the physical.

The moral I draw from that is that phenomenal concepts are not bare referential devices. They incorporate some substantive conception of their referents. If they are demonstratives, they have a tacit theoretical sortal attached. We wonder, not simply, “What’s this?”, but “What’s this phenomenal feel?”.

What is this substantive conception of the phenomenal? I think it’s roughly the one Daniel Dennett dismantled in “Quining qualia” — the concept of a qualitative state that is private, ineffable, intrinsic, and immediately apprehended. Maybe those commitments are qualified in various ways, but they are still strong enough to make the conception incompatible with our conception of the physical. Hence our puzzlement.

If that’s right, then there’s only one option for the physicalist, and that is to say that phenomenal concepts misrepresent their referents. The properties they pick out (assuming they pick out determinate properties at all, which they may not) aren’t really phenomenal ones. And that’s illusionism.

For twenty-odd years, the PCS has acted as a band-aid holding physicalism and phenomenal realism together, and it’s worn out.

Accelerating research on consciousness

Back in December, psychologist and author Christian Jarrett got in touch to ask what I thought about the new project “Accelerating Research on Consciousness” organised by the Templeton World Charity Foundation. See this news story for more information about the project. Christian incorporated some of my comments into an article for BBC Focus magazine (which I recommend) but I thought I’d post my full reply here, in case anyone is interested. Here it is.

I have mixed feelings about the project. I’m delighted to see more funding for experimental work on consciousness. The data collected will undoubtedly be useful. I have worries, however. It looks like the project will focus on explaining consciousness in the phenomenal sense. That is, the organizers and participants conceive of conscious states as essentially subjective ones, involving awareness of phenomenal properties or qualia (the private mental ‘feel’ or ‘what-it-likeness’ of experience). If that’s right, then I am dubious of the chances of making decisive progress.

To begin with, it’s hard to see how one could explain phenomenal properties in terms of brain processes. The two things are just too different. (This is the so-called ‘hard problem’ of consciousness.) The most we can hope to do is to find correlations between brain processes and phenomenal properties. And even then there’s a methodological problem. For there can be no objective test for the presence of essentially subjective properties. The best we can do is to test for objective indications of their presence, such as the subject’s reports and reactions. And this means that tests of correlation hypotheses can never be decisive. Suppose theory A says that conscious state C occurs when brain region N1 is active, whereas theory B says that N1 isn’t sufficient on its own and that brain region N2 needs to be active as well. And suppose we run some experiments and find that participants report C when both N1 and N2 are active but not when only N1 is. Does this prove that theory A is wrong and theory B right? No. It might be that N1 is sufficient for C, but that N2 is needed to enable us to report it. The same problem will arise if we try to test for nonverbal indications of C. Again, how do we tell which brain states are necessary for the conscious state itself and which are necessary for producing the behavioural indications of it? Since there is no way of directly testing for subjective properties, we can never definitively rule out any theory.

In short, so long as we focus on phenomenal consciousness, we’re never going to have decisive tests of our theories. The moral I draw is that shouldn’t focus on phenomenal consciousness. In fact, I believe that we do not have phenomenal consciousness; it’s a kind of introspective illusion, which reflects the limited access we have to our own mental processes. (I call this view ‘illusionism.’) The real task is to explain our intuitions about phenomenal consciousness — why we think we possess it.

As regards the theories currently being tested, I am very sceptical of IIT. It is intended as a theory of phenomenal consciousness, so the worries I’ve just mentioned apply, but even as theory of that, IIT is implausible. All kinds of things can have a rich informational structure in the relevant sense, so the theory has the consequence that inanimate objects can be phenomenally conscious. Even a blank wall could be.

I am much more sympathetic to Global Workspace theory, though I think it should be construed as a theory of access consciousness — of the awareness of information in a functional sense — rather than phenomenal consciousness. Moreover, it needs to be supplemented with some account of why we think we have phenomenal consciousness.

As for what I’d like to see next: Unsurprisingly, I’d like to see the project test illusionist theories of consciousness, which focus on explaining our intuitions about phenomenal consciousness. These do not face the problems I’ve mentioned, and they offer a promising line of research. It’s early days yet, but such theories are being developed. A good example is the Action Schema Theory proposed by the Princeton neuroscientist Michael Graziano and his colleagues.

The bottom line, then, is that the funding for experimental work is welcome and the data gathered will be useful, but the project is unlikely to settle anything until we have a better conception of exactly what it is we are trying to explain.

Bright Shiny Colours

What are colours? My view is that they are properties of surfaces in the world around us — albeit complex gerrymanded ones, which can be picked out only by reference to our reactions to them. Blue things are things that evoke a certain distinctive cluster of reactive dispositions in us. Note that that I do not say that they are ones that produce blue sensations in us. I don’t think that experiencing blue involves entertaining a mental version of blueness — a blue quale or phenomenal property.

Where then is the quality of blueness ? It’s not out there in the world. Out there there’s just a surface with a microstructure that reflects certain wavelengths of electromagnetic radiation. And I’ve denied that there is any blue quality in our minds. So where is the blueness of the blue?

My answer that it is not really anywhere. It’s a property that our minds misrepresent external objects as having. However, it’s a property that corresponds to, and carries information about, something real and important — namely, the affordances of the objects in question. That needs a lot of unpacking and qualification, but the general idea is this. We are tuned up, by biological evolution, cultural evolution, and personal experience, to track worldly properties that it’s useful for us to notice. Such properties afford us opportunities for action in various ways; they have specific affordances. An object’s affordances are reflected in the suite of reactive dispositions its perception triggers in us — the suite of beliefs, expectations, associations, emotions, priming effects, and so on.

Now my suggestion is that the human brain monitors its own reactive dispositions and generates schematic representations of them, which are linked to its representations of the objects that triggered them. The upshot of this is that we experience the world as being metaphorically coloured by our reactions to it. We experience objects as having a distinctive but ineffable significance for us, which is a marker of their affordances. This is what we call their quality or feel. The blueness of blue is a distorted representation of the affordances it presents, represented as a property of the object itself.

That’s still very schematic, but a little example may help. Consider shiny, metallic colours, such as silver and gold. These seem to have a distinctive feel to them, and as a child I was very puzzled as to where they fitted into the visible spectrum. But, of course, they are not really different colours. Shiny things are just regularly coloured things whose brightness (and colour if they are very shiny) varies markedly with viewing angle. What gives them their distinctive ‘feel’ is precisely the affordances they present. We expect them to change in a distinctive way as we move in relation to them. The ‘feel’ of metallic colour just is the expectation of this effect.

A postscript: Another illustration of this is afforded by Gregory Thielker’s paintings of scenes though rain-spattered glass. In me, these create a powerful response (‘feel’, if you like). Doubtless, this is in part because they evoke memories of glum hours spent in traffic during rainy commutes. But I think it also reflects the way they trigger strong expectations that the scene will morph and distort in a distinctive way as the water drips or I move my head.

Illusion or identity?

Illusionists believe that consciousness involves no properties that are not detectable and fully describable by third-person science. Any other properties we think are involved are illusory. Suppose that’s right. Still, why should it follow that phenomenal properties are illusory? Why not say that they are properties that are detectable and fully describable by third-person science? It’s true (the objection continues) that we think of phenomenal properties as ones that present a problem for science — that pose a hard problem — but it doesn’t follow that they really do present one. Maybe we are just wrong about them.

Suppose that phenomenal concepts do in fact track completely unmysterious brain properties, which for some reason we mistakenly think of as nonphysical. There are many candidate explanations of why we might do this. If that’s the case (and illusionists don’t deny the possibility), then wouldn’t it be better to say that phenomenal properties are real but different from what we thought?

Here’s my answer. Maybe we could say that. It’s a revise-or-eliminate situation, and there is no simple procedure for determining the best way to go. But here are some reasons for rejecting the revisionary route.

First, it would invite confusion. The concept of the phenomenal carries a lot of connotations that physicalists must reject — assumptions about the reliability of introspection, intuitions about well-known thought experiments, associations with dualist notions such as sense data, and so on. Using a term with all this theoretical baggage is not the most perspicuous way of presenting a physicalist theory of consciousness.

Second, it would be misleading. The notion of phenomenal consciousness has become bound up with that of the hard problem — a problem that is supposed to be both substantive (there’s a real thing that needs explaining) and qualitatively different from ‘easy’ problems that can be solved by cognitive science. To offer a theory of phenomenal consciousness is to suggest that one has solved this hard problem, and physicalists shouldn’t do that. For physicalists, there is no hard problem, only the problem of explaining why there seems to be one.

Third, it would be tedious. In theoretical work, we’d have to laboriously disinfect phenomenal concepts before use, explicitly disavowing all their theoretical accretions.

Fourth, it would be pointless. After disinfection, we’d be left with nothing more than a bare demonstrative or quotational device, equivalent to ‘whatever this is’, applied introspectively. It’s not clear that this would pick out something determinate or theoretically interesting. We’d be gesturing at the whole complex perceptual-cum-reactive state triggered by the current stimulus, and without further specification it’s doubtful that the gesture would pick out a clear target for scientific investigation. (By contrast, gesturing at the supposed qualitative aspect of the state would narrow down the target, but only to something that physicalists must say is illusory.)

Fifth, it’s restricting. Physicalists need phenomenal concepts in their old theoretically laden senses in order to describe how people mistakenly think of consciousness (‘It seems that experiences have a phenomenal aspect as well as a functional one’). Compare the term ‘witch’. If we revise it to mean female naturopath, then it becomes harder to express what mediaeval people thought. After all, they were right to think that there were witches in that sense. Of course, this is only a linguistic problem and it could be solved by paraphrase, but it’s a consideration.

In the end, the concept of the phenomenal is too compromised to be useful to science. As Daniel Dennett says in his Consciousness Explained, let’s cut the tangled kite string and start over. Phenomenal properties are illusory.

The trolley problem murder

Moriarty wants to kill Holmes but doesn’t want to run the risk of being convicted for murder. So he plans to get an innocent person to do the dirty work for him. Here’s what he does.

First, he persuades Holmes (with whom he is ostensibly on good terms) and three of his Baker Street Irregulars to take part in a real-life philosophical experiment. He will tie the three Irregulars to a trolley track, near to a spur on which Holmes will be tied. He will wait till there are a number of bystanders near where the spur branches off, then release a trolley down the main track in the direction of the Irregulars, and wait to see if one of the bystanders throws the lever to divert the trolley onto the spur. The experiment will provide the philosophical world with important data on the famous trolley problem.

Moriarty shows everyone that the trolley has an automatic braking mechanism that will prevent it hitting the Irregulars if the lever is not thrown. This mechanism really does work, but Moriarty has adjusted it so that if the trolley is sharply diverted onto another track, it will fail. Everyone agrees to take part.

It all goes to plan. Moriarty releases the trolley, a bystander, Doyle, sees the trolley and the people on the tracks, does some rapid moral reasoning, and operates the lever, believing that this will result in the death of the person on the spur. The trolley goes onto the spur, its braking mechanism fails, and Holmes is killed.

Moriarty’s plan has worked. Holmes is dead, yet Moriarty did not kill him. If Doyle had not intervened, no one would have been harmed. Instead, Doyle freely chose to do something which he believed would kill Holmes.

Or was there a flaw in the plan? Did Moriarty commit a crime? If so, what was it? Who is morally responsible for Holmes’s death? Does it matter if you think Doyle’s moral reasoning was faulty?

(Revised and expanded after twitter discussion with @JulianSales2, @FillinghamLydia, and @tylerhower.)


With apologies to John Lennon

Imagine there’re no qualia
It’s easy if you try
No feel or what-its-likeness
Just plain old cog sci

Imagine all the zombies
Being just like us

Imagine there’re no inverts
It isn’t hard to do
Nothing for Mary to learn
And no hard problem, too

Imagine all the people
Being illusionist

You may say I’m a quiner
But there’s nothing wrong with that
I hope someday you’ll join us
And learn what it’s like to be a bat.