Tag Archives: subjectivity

The Incredible Consciousness of Edward Witten

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Edward WittenWe’ll never understand consciousness, says Edward Witten. Ashutosh Jogalekar’s post here features a video of the eminent physicist talking about fundamentals; the bit about consciousness starts around 1:10 if you’re not interested in string theory and cosmology. John Horgan has also weighed in with some comments; Witten’s view is congenial to him because of his belief that science may be approaching an end state in which many big issues are basically settled while others remain permanently mysterious. Witten himself thinks we might possibly get a “final theory” of physics (maybe even a form of string theory), but guesses that it would be of a tricky kind, so that understanding and exploring the theory would itself be an endless project, rather the way number theory, which looks like a simple subject at first glance, proves to be capable of endless further research.

Witten, in response to a slightly weird question from the interviewer, declines to define consciousness, saying he prefers to leave it undefined like one of the undefined terms set out at the beginning of a maths book. He feels confident that the workings of the mind will be greatly clarified by ongoing research so that we will come to understand much better how the mechanisms operate. But why these processes are accompanied by something like consciousness seems likely to remain a mystery; no extension of physics that he can imagine seems likely to do the job, including the kind of new quantum mechanics that Roger Penrose believes is needed.

Witten is merely recording his intuitions, so we shouldn’t try to represent him as committed to any strong theoretical position; but his words clearly suggest that he is an optimist on the so-called Easy Problem and a pessimist on the Hard one. The problem he thinks may be unsolvable is the one about why there is “something it is like” to have experiences; what it is that seeing a red rose has over and above the acquisition of mere data.

If so, I think his incredulity joins a long tradition of those who feel intuitively that that kind of consciousness just is radically different from anything explained or explainable by physics. Horgan mentions the Mysterians, notably Colin McGinn, who holds that our brain just isn’t adapted to understanding how subjective experience and the physical world can be reconciled; but we could also invoke Brentano’s contention that mental intentionality is just utterly unlike any physical phenomenon; and even trace the same intuition back to Leibniz’s famous analogy of the mill; no matter what wheels and levers you put in your machine, there’s never going to be anything that could explain a perception (particularly telling given Leibniz’s enthusiasm for calculating machines and his belief that one day thinkers could use them to resolve complex disputes). Indeed, couldn’t we argue that contemporary consciousness sceptics like Dennett and the Churchlands also see an unbridgeable gap between physics and subjective, qualia-having consciousness? The difference is simply that in their eyes this makes that kind of consciousness nonsense, not a mystery.

We have to be a bit wary of trusting our intuitions. The idea that subjective consciousness arises when we’ve got enough neurons firing may sound like the idea that wine comes about when we’ve added enough water to the jar; but the idea that enough ones and zeroes in data registers could ever give rise to a decent game of chess looks pretty strange too.

As those who’ve read earlier posts may know, I think the missing ingredient is simply reality. The extra thing about consciousness that the theory of physics fails to include is just the reality of the experience, the one thing a theory can never include. Of course, the nature of reality is itself a considerable mystery, it just isn’t the one people have thought they were talking about. If I’m right, then Witten’s doubts are well-founded but less worrying than they may seem. If some future genius succeeds in generating an artificial brain with human-style mental functions, then by looking at its structure we’ll only ever see solutions to the Easy Problem, just as we may do in part when looking at normal biological brains. Once we switch on the artificial brain and it starts doing real things, then experience will happen.

Alters of the Universe

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world alterBernardo Kastrup has some marvellous invective against AI engineers in this piece…

The computer engineer’s dream of birthing a conscious child into the world without the messiness and fragility of life is an infantile delusion; a confused, partial, distorted projection of archetypal images and drives. It is the expression of the male’s hidden aspiration for the female’s divine power of creation. It represents a confused attempt to transcend the deep-seated fear of one’s own nature as a living, breathing entity condemned to death from birth. It embodies a misguided and utterly useless search for the eternal, motivated only by one’s amnesia of one’s own true nature. The fable of artificial consciousness is the imaginary band-aid sought to cover the engineer’s wound of ignorance.

I have been this engineer.

I think it’s untrue, but you don’t have to share the sentiment to appreciate the splendid rhetoric.

Kastrup distinguishes intelligence, which is a legitimate matter of inputs, outputs and the functions that connect them, from consciousness, the true what-it-is likeness of subjectivity. In essence he just doesn’t see how setting up functions in a machine can ever touch the latter.

Not that Kastrup has a closed mind, he speaks approvingly of Pentti Haikonen’s proposed architecture; he just doesn’t think it works. As Kastrup sees it Haikonen’s network merely gathers together sparks of consciousness: it then does a plausible job of bringing them together to form more complex kinds of cognition, but in Kastrup’s eyes it assumes that consciousness is there to be gathered in the first place: that it exists out there in tiny parcels amendable to this kind of treatment. There is in fact, he thinks, absolutely no reason to think that this kind of panpsychism is true: no reason to think that rocks or drops of water have any kind of conscious experience at all.

I don’t know whether that is the right way to construe Haikonen’s project (I doubt whether gathering experiential sparks is exactly what Haikonen supposed he was about). Interestingly, though Kastrup is against the normal kind of panpsychism (if the concept of  ‘normal panpsychism’ is admissible), his own view is essentially a more unusual variety.

Kastrup considers that we’re dealing with two aspects here; internal and external; our minds have both; the external is objective, the internal represents subjectivity. Why wouldn’t the world also have these two aspects? (Actually it’s hard to say why anything should have them, and we may suspect that by taking it as a given we’re in danger of smuggling half the mystery out of the problem, but let that pass.) Kastrup takes it as natural to conclude that the world as a whole must indeed have the two aspects (I think at this point he may have inadvertently ‘proved’ the existence of God in the form of a conscious cosmos, which is regrettable, but again let’s go with it for now); but not parts of the world. The brain, we know, has experience, but the groups of neurons that make it up do not (do we actually know that?); it follows that while the world as a whole has an internal aspect, objects or entities within it generally do not.

Yet of course, the brain manages to have two aspects, which must surely be something to do with the structure of the brain? May we not suspect that whatever it is that allows the brain to have an internal aspect, a machine could in principle have it too? I don’t think Kastrup engages effectively with this objection; his view seems to be that metabolism is essential, though why that should be, and why machines can’t have some form of metabolism, we don’t know.

The argument, then, doesn’t seem convincing, but it must be granted that Kastrup has an original and striking vision: our consciousnesses, he suggests, are essentially like the ‘alters’ of Dissociative Identity Disorder, better known as Multiple Personality, in which several different people seem to inhabit a single human being. We are, he says, like the accidental alternate identities of the Universe (again, I think you could say, of God, though Kastrup clearly doesn’t want to).

As with Kastrup’s condemnation of AI engineering, I don’t think at all that he is right, but it is a great idea. It is probable that in his book-length treatments of these ideas Kastrup makes a stronger case than I have given him credit for above, but I do in any case admire the originality of his thinking, and the clarity and force with which he expresses it.

Haecceity

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knight 3This is the third in a series of four posts about key ideas from my book The Shadow of Consciousness; this one is about haecceity, or to coin a plainer term, thisness. There are strong links with the subject of the final post, which will be that ultimate mystery, reality.

Haecceity is my explanation for the oddity of subjective experience. A whole set of strange stories are supposed to persuade us that there is something in subjective experience which is inexpressible, outside of physics, and yet utterly vivid and undeniable. It’s about my inward experience of blue, which I can never prove is the same as yours; about what it is like to see red.

One of the best known thought experiments on this topic is the story of Mary the Colour Scientist. She has never seen colour, but knows everything there is to know about colour vision; when she sees a red rose for the first time, does she come to know something new? The presumed answer is yes: she now knows what it is like to see red things.

Another celebrated case asks whether I could have a ‘zombie’ twin, identical to me in every physical respect, who did not have these purely subjective aspects of experience – which are known as ‘qualia’, by the way. We’re allowed to be unsure whether zombie twin is possible, but expected to agree that he is at least conceivable; and that that’s enough to establish that there really is something extra going on, over and above the physics.

Most people, I think, accept that qualia do exist and do raise a problem, though some sceptics denounce the entire topic as more or less irretrievable nonsense. Qualia are certainly very odd; they have no causal effects, so nothing we say about them was caused by them: and they cannot be directly described. What we invariably have to do is refer to them by an objective counterpart: so we speak of the quale of hearing middle C, though middle C is in itself an irreproachably physical, describable thing (identifying the precisely correct physical counterpart for colour vision is actually rather complex, though I don’t think anyone denies that you can give a full physical account of colour vision).

I suggest we can draw two tentative conclusions about qualia. First, knowledge of qualia is like knowledge of riding a bike: it cannot be transferred in words. I can talk until I’m blue in the face about bike riding, and it may help a little, but in the end to get that knowledge you have to get on a bike. That’s because for bike riding it’s your muscles and some non-talking parts of your brain that need to learn about it; it’s a skill. We can’t say the same about qualia because experiencing them is not a skill we need to learn; but there is perhaps a common factor; you have to have really done it, you have to have been there.

Second, we cannot say anything about qualia except through their objective counterparts. This leaves a mystery about how many qualia there are. Is there a quale of scarlet and a quale of crimson? An indefinite number of red qualia? We can’t say, and since all hypotheses about the number of qualia are equally good, we ought to choose the least expensive under the terms of Occam’s Razor; the one with the fewest entities. It would follow from that that there is really only one universal quale; it provides the vivid liveliness while the objective aspects of the experience provide all the content.

So we have two provisional conclusions: all qualia are really the same thing conditioned differently by the objective features of the experience; and to know qualia you have to have ‘been there’, to have had real experience. I think it follows naturally from these two premises that qualia simply represent the particularity of experience; its haecceity. The aspect of experience which is not accounted for by any theory, including the theories of physics, is simply the actuality of experience. This is no discredit to theory: it is by definition about the general and the abstract and cannot possibly include the particular reality of any specific experience.

Does this help us with those two famous thought experiments? In Mary’s case it suggests that what she knows after seeing the rose is simply what a particular experience is like. That could never have been conveyed by theoretical knowledge. In the case of my zombie twin, the real turning point is when we’re asked to think whether he is conceivable; that transfers discussion to a conceptual, theoretical plane on which it is natural to suppose nothing has particularity.

Finally, I think this view explains why qualia are ineffable, why we can’t say anything directly about them. All speech is, as it were, second order: it’s about experiences, not the described experience itself. When we think of any objective aspect, we summon up the appropriate concepts and put them over in words; but when we attempt to convey the haecceity of an experience it drops out as soon as we move to a conceptual level. Description, for once, cannot capture what we want to convey.

There’s nothing in all this that suggests anything wrong or incomplete about physics; no need for any dualism or magic realm. In a lot of ways this is simply the sceptical case approached more cautiously and from a different angle. It does leave us with some mystery though: what is it for something to be particular; what is the nature of particularity? We’ve already said we can’t describe it effectively or reduce it theoretically, but surely there must be something we can do to apprehend it better? This is the problem of reality…

[Many thanks to Sergio for the kind review here. Many thanks also to the generous people who have given me good reviews on amazon.com; much appreciated!]

Strange Smells of the Mind

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smellingAn intriguing paper from Benjamin D. Young claims that we can have phenomenal experiences of which we are unaware – although experiences of which we are aware always have phenomenal content. The paper is about smell, though I don’t really see why similar considerations shouldn’t apply to other senses.

At first sight the idea of phenomenal experience of which we are unaware seems like a contradiction in terms. Phenomenal experience is the subjective aspect of consciousness, isn’t it? How could an aspect of consciousness exist without consciousness itself? Young rightly says that it is well established that things we only register subconsciously can affect our behaviour – but that can’t include the sort of experience which for some people is the real essence of consciousness, can it?

The only way I can imagine subjectivity going on in my head without me experiencing it is if someone else were experiencing it – not a matter of me experiencing things subconsciously, but of my subconscious being a real separate entity, or perhaps of it all going on in the mind of alternate personality of the kind that seems to occur is Dissociative Identity Disorder (Multiple Personality, as it used to be called).

On further reflection, I don’t think that’s the kind of thing Young meant at all: I think instead he is drawing a distinction between explicit and inexplicit awareness. So his point is that I can experience qualia without having any accompanying conscious thought about those qualia or the experience.

That’s true and an important point. One reason qualia seem so slippery, I think, is that discussion is always in second order terms: we exchange reports of qualia. But because the things themselves are irredeemably first order they have a way of disappearing from the discussion, leaving us talking about their effable accompaniments.

Ironically, something like that may have happened in Young’s paper, as he goes on to discuss experiments which allegedly shed light on subjective experience. Smell is a complex phenomenon of course; compared with the neat structure of colours the rambling and apparently inexhaustible structure of smell space is daunting;y hard to grasp. However, smell conveniently has valence in a way that colours don’t: some smells are nice and some are nasty. Humans apparently vary their sniff rate partly in response to a smell’s valence and Young thinks that this provides an objective, measurable way into the subjectivity of the experience.

Beyond that he goes on to consider mating choice: it seems human beings, like other mammals, choose their mates partly on the basis of smell. I imagine this might be controversial to some, and some of the research Young quotes sounds amusingly naive. In answer to a questionnaire, female subjects rated body odour as an important factor in selecting a sexual partner; well yes, if a guy smells you’re maybe not going to date him, huh?

I haven’t read the study which was doubtless on a much more sophisticated level, and Young cites a whole wealth of other interesting papers. The problem is that while this is all fascinating psychologically, none of it can properly bear on the philosophical issue because qualia, the ultimate bearers of subjectivity, are acausal and cannot affect our behaviour. This is shown clearly by the zombie twin argument: my zombie twin has no qualia but his behaviour is ex hypothesi the same as mine.

Still, the use of valence as a way in is interesting. The normal philosophical argument is that we have no way of telling whether my subjective red is your subjective green: but it’s hard to argue that m subjective nasty is your subjective nice (unless we also hypothesise that you seek out nasty experiences and avoid nice ones?).