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How To Be Conscious: Mind & Matter Revisited
What exactly is consciousness? Roger Caldwell looks at the current ideas of three leading figures in philosophy of mind, as revealed in their latest books.
From being a neglected aspect of the philosophy of mind the problem of consciousness has moved in recent years to be one of the hottest topics. But what progress has been made? How far are we towards a consensus? Three new books by long-standing practitioners in the field – Daniel Dennett, John Searle, and Colin McGinn – offer three very different views. The oddity is that all three start from what is essentially the same standpoint, that of scientific naturalism. That is, all three believe that human consciousness is dependent on brain-states, and that it has emerged by essentially Darwinian mechanisms as a natural (rather than supernatural) feature of the world. But that is where the consensus ends.
Why is there a problem of consciousness? Why is it not enough to accept it as a natural feature of our world? Simply put, whereas science offers us a third-person view of the world, consciousness offers only what appears to be a first-person view. I have a privileged perspective on what it feels like to be me that is not available to anyone else: another person may empathise with my joys and sorrows, or my pains, but only I can actually experience them. Even if we accept that mental states are the product of brain-states, so that, say, when I do an addition sum in my head or try to remember a piece of music, certain areas of the brain light up, it is not possible for the neuroscientist to peer inside my brain and see what I am thinking. Indeed, we routinely hide our thoughts from others: it is only rarely that others can ‘read’ them from our face.
This essentially ‘first-person’ aspect of consciousness makes it difficult to assimilate into the scientific world-picture. Science deals with what is observable; typically it deals also with what is measurable and occupies a position in space. Consciousness arguably conforms to none of these requirements. It is not observable: we have no criteria by which to identify at what point consciousness begins. Apes and dogs we assume are conscious, flowers and seaweed we assume are not, but what about snakes, fish, mosquitoes, amoebae? We think of conscious thoughts as being in our heads, but our emotional states, such as anger or joy, appear to permeate our whole body. Our emotions and thoughts are not precisely located in space and they cannot be measured.
Further, it is the case that all our experiences are mood-laden, that is to say that we live our lives in states ranging from boredom or lethargy at one end to high excitement at the other. In this we are different from machines. In this we are also different from mosquitoes, which are more like programmed natural robots – nature’s heat-seeking missiles. Certainly we can perform learned or routine tasks robotically, but that doesn’t mean that mental activity ceases: much of our routine activity is carried out unconsciously whilst we think of other things.
Sooner or later in the literature on consciousness one comes across the phenomenon of blindsight which, on one interpretation, illustrates the difference between robotic and conscious intentional activity. Blindsight involves damage to the visual cortex that results in the subject denying that he is able to see. In fact, testing can demonstrate that the subject is still able to make visual discriminations with a high degree of success. The situation is that the person can see, in the sense of being able to make those discriminations, but has no awareness of doing so. In the same way robots (including natural robots like mosquitoes) are able to perform certain functions but are not aware that they are performing them.
It appears that not only can our brain-states result in consciousness but that consciousness has causal efficacy: it can make things happen. We act on reasons, on knowledge, on hunches, on intuitions that appear to be irreducible to simply biological processes. Indeed, if consciousness didn’t have such causal efficacy it is hard to see why it evolved in the first place or why it has come to be such an important part of life. But so put, we are in danger of sliding into Cartesian dualism – that is, of postulating two kinds of substances in the world, physical ones and mental ones – and then having the intractable problem of how they relate. This is a position that Dennett, Searle and McGinn all robustly resist.
Daniel Dennett’s Sweet Dreams
Dennett is one of the pioneers in the field: his first book on the subject, Content and Consciousness, appeared back in 1969, and he has continued to refine and build his views in a long series of articles and books. His latest book, Sweet Dreams, offers no great conceptual surprises, but attempts further to defend his positions against his critics. What those critics allege is that Dennett not so much explains consciousness as attempts to explain it away. Naturally, he resists this as caricature: what he is trying to do, he claims, is to show that consciousness is not what we have taken it to be.
For example, it is not the case that we are the privileged observers of our own mental states. We are not authoritative about what is happening in our heads, but only about what seems to be happening in our heads. A commonplace example is when our emotional feelings towards another – say, of love or jealousy – are not apparent to ourselves but are apparent to others through our actions. Indeed, it may be only when pointed out to us how we are behaving towards that person that we become aware of those feelings and – perhaps reluctantly – admit to them.
More radically, we often confabulate reasons for our actions. A subject who is put under hypnosis may post-hypnotically go on to perform the action suggested to him, but when asked why he did it will offer his own personal reasons (however improbable) as to why he did those actions and, what is more, appear to believe those reasons. Dennett holds, in effect, that we are always telling such stories to ourselves. Certainly, consciousness is an emergent property from an organisation of physical systems but, as he points out, although different parts of the brain have been shown to be associated with different sorts of mental activity, there is no part of the brain that serves to co-ordinate or direct all those sub-activities. Rather, on his model there is pandemonium – lots of small agents competing for attention with no central headquarters in control. We must think of multiple channels exerting simultaneous influence, of a variety of sub-systems talking to one another. There are what he calls ‘multiple drafts’ of what is going on. There is no final draft in the sense of one that is an accurate report: in a sense the ‘I’ is an illusion, a succession of ‘virtual captains’.
Dennett advocates a third-person approach to consciousness (what he calls ‘heterophenomenology’) – that is, we try to investigate the contents of consciousness from the outside to the point where we can claim that what we have discovered is ‘without significant residue’. Even of physical systems, he points out, there is always more than can be said in our scientific descriptions; even of a grain of sand there is no sense in which our description can be exhaustive. However, we do not need it to be exhaustive; we need no more than provides a basic understanding. So it is with consciousness, which if we look at it closely is less mysterious than we have supposed it to be. The supposed intrinsic subjectivity of consciousness is a myth in that it is possible to ‘externalize’ that subjectivity. Indeed, that is what happens when we enjoy a poem, a novel, or a symphony: the artist’s subjectivity is made publicly available to us through the art-work. In a less thoroughgoing fashion this is what happens in our relations with others in so far as we successfully communicate our thoughts and feelings.
It is undeniable that Dennett, in attempting to make consciousness less mysterious, is also trying to chip away at what we think of as our intrinsically subjective experiences or ‘qualia’. But, for all the resourcefulness of his arguments, one might think that there is more of a ‘significant residue’ left over than he is willing to admit. Further, the I who is conscious has surely to be more of an unified entity than Dennett is prepared to allow. Elsewhere Dennett acknowledges that human language and culture create a space for agency, and for the creation of ourselves as ‘persons’. Nonetheless, if ultimately no one is really in control, we are back with a version of the old behaviourist dilemma. That is, on Dennett’s account it is hard to see who it is who is proposing the theories in question, and who quite is in a position to accept or resist them. It is hard to see how a succession of ‘virtual captains’ could ever fill this role.
John Searle on Mind
Searle robustly rejects any theory such as Dennett’s which attempts, in effect, to minimize the subjectivity of consciousness. For Searle, if I think I am conscious, then I am conscious. I can make mistakes about the contents of my consciousness – as Dennett abundantly shows – but I can’t make mistakes as to their very existence. Dennett may reduce the contents of mental states, but he fails to close the gap between the first and third person.
In a succession of books Searle has argued against the project of Artificial Intelligence that sees the mind as a sort of computer. For Searle this is not in fact to say very much, since to say that something is a computer is not to ascribe an intrinsic property to that object but only to state how it may be used. In an article which first appeared in 1980 and has never been out of print since, Searle put forward the famous ‘Chinese Room’ argument. Briefly, the story is that of a man sitting in a room with a big manual full of symbols. From time to time, someone slides a card with some symbols on it into the room through a slot in the wall. The man in the room looks up the symbols in his book, and in accordance with its instructions selects another card with symbols on and pushes it out through the slot. The symbols are in fact Chinese characters, and it appears to the person outside the room that he is having a conversation in Chinese with the man in the room. The question is: does this show that the man in the room understands Chinese? For Searle the answer has to be a resounding No. There is a difference between running a computer program (to which this thought-experiment is an analogy) and having conscious knowledge. The computer operates by manipulating symbols, but the human mind attaches meaning to those symbols.
For Searle it is a fact of the matter that biological processes produce conscious mental phenomena that are irreducibly subjective. But he claims there is nothing particularly mysterious about this: consciousness is as much a biological process as digestion or photosynthesis. Rather, it is a fact of the matter that the world works in such a way that “some biological processes are qualitative, subjective, and first personal”. Consciousness is an emergent property of the brain much as the solidity of a piece of wood is an emergent property of the atomic microstructure out of which it is composed. Conscious states are real and have effects in the world. However, the causal powers of consciousness are one and the same as those of its neuronal base: it is just that in talking of consciousness we are describing brain functioning at a higher level than that of neurons and synapses.
Searle, unlike Dennett, is robustly realist about conscious states, and readily concedes that there is an inner sense of what it feels to be myself that is not available to others. Indeed, he stresses the degree to which the world in which we live is the product of consciousness. There are, of course, real features of the world as described by science that are observer-independent: stars and planets, ostriches and aardvarks would exist even if there were no humans around to observe them. But there are also real features of the world that are observer-dependent, that have been brought into being by human intentionality: it is no more possible to deny that money, governments, yacht clubs, taxes, terrorists, marriage and post offices are in some sense ‘real’ than to deny that human mental states are.
Searle’s position saves us from Cartesian dualism or substance dualism, but it surely resolves into a form of what is called property dualism. Substance dualism requires there to be two different sorts of stuffs in the world, mental stuff on the one hand, physical stuff on the other. Property dualism requires only one kind of stuff, but demands that it is possible for it to be considered from two different perspectives, the physical and the mental. I understand that Searle resists the label, but much of what he says surely presupposes such a position. He tells us that conscious states are causally reducible to neurobiological processes, but that, though they are real features of the world, they are not in any sense ‘over and above’ those neurobiological processes. This can only be the case if, in some sense, they are identical.
Searle, like Dennett, tries to demystify consciousness, but most have not found the analogies with solidity or digestion that he proposes to be convincing. The solidity of the chair is not so much caused by the atomic microstructure but is one and the same as that atomic microstructure. It is, to say the least, not obvious that this is the case with brain-states and mental states, not least because we know that there can be brain-states without consciousness (as in the case of blindsight). Surely we require more than Searle offers us if we are to understand quite how consciousness emerges, how all these resplendent thoughts come from such unprepossessing grey matter? But it seems that Searle believes himself to have solved the conceptual problem; he leaves it up to the neuroscientists to fill in the scientific details.
Colin McGinn on Consciousness and its Objects
Colin McGinn, unlike Searle, is sceptical about the role of the neuroscientist: for him the mere discovery of further empirical correlations between the mental and the physical is never going to bring the two conceptually together. It is not enough to assert, as Searle does, that some physical states give rise to mental states: we need an explanation of why some do so and others don’t. He quotes Saul Kripke to the effect that when God created pain he had to do more than create C-fibre firing, whereas to create heat it sufficed to create molecular motion. That is to say, heat reduces without residue to molecular motion, but pain can never be reduced without residue to events in the brain.
McGinn then goes on to question the feasibility of arriving at a coherent account as to how this is possible, thus attracting the label of ‘Mysterian’. This he understandably resists. On the contrary, he says: he accepts that there is a naturalistic explanation of how physical processes can give rise to mental ones, only he doubts that we as human beings are capable of arriving at that explanation. To understand how the mental interacts with the physical we require a concept that links the two and yet belongs to neither category. The problem is, that from the human perspective, the mental and the physical are exhaustive of how we perceive reality. What other categories can there possibly be? We have arrived at no solution to the mind-body problem, because the problem exceeds the limits of our current concepts of the mental and the physical. Our inherent bias towards explanation in terms of spatiality works well as regards the physical world – hence the prodigious successes of science – but fail us when it comes to “the intrinsic non-spatiality of the mental”.
Our successes in scientific explanation should not fool us into thinking that human beings are ever going to be in the position of having explained everything that there is to explain. The problem of consciousness is not an exception in this. Some of the best minds from the Ancient Greeks to the present day have grappled with a series of problems – such as that of free will, of the nature of the self, the question of a priori and empirical knowledge – and still not come up with generally acceptable solutions. This is not because of any lack of intelligence in the philosophers concerned but rather because such problems are, in McGinn’s words, “beyond the rim of human intellectual competence.” That such problems are found to be intractable is not to suggest that they are meaningless or that there is no answer, only that the answer is, because of the way natural selection has built our brains, simply not available to us.
In speculating in this fashion McGinn is of course in danger of putting philosophers (himself included) out of business. Are things really so dire? In respect of the problem of consciousness it might be thought that, in demanding a sort of one-to-one necessary relationship between physical and mental events – say, between C-fibre firing and pain – he is being unrealistic. Clearly, there is no single interlevel gap; it is, rather, a matter of complex levels of organisation between neurophysiological processes and conscious experiences. It is likely that we can experience pain even in the absence of C-fibre firing, and it is quite clear the C-fibre firing by no means always results in pain. From our own experience of pain from an organic cause, say that of toothache, we know that it is intermittent: if we are preoccupied with other matters then it disappears, only to return when we are disengaged. In general McGinn fails to take into account the diversity of levels in complex systems.
It is true that, although thinkers like Dennett and Searle have made immense contributions to our thinking about consciousness (and, indeed, other matters), a good deal is left unexplained; none of the solutions on offer can command consensus. That doesn’t mean that they may not have made some progress towards the truth. Consciousness is not, as McGinn tends to present it, an all-or-nothing affair, but patchy, intermittent, and very various in its manifestations. Not only will human consciousness, with its self-reflective quality through the medium of language, differ from that of a dog, but canine consciousness will surely be very different from that of a bat. Further, consciousness is not a single ‘stuff’ – hence the difficulty of providing a definition of it – but includes such very various phenomena as having a headache, trying to remember a song, experiencing jealousy or wild joy, or planning how to invade Poland. What may be required is not a single overriding explanation or a single conceptual innovation, but rather a number of explanations relating to different modes or types of consciousness.
McGinn may well be right that there are necessary limits to human knowledge, but one of those limits may well be that we can never discover where those limits lie. McGinn’s project is essentially a Kantian one. Immanuel Kant once decreed that human understanding was such that we necessarily saw the world in terms of cause and effect, and in terms of Euclidean space. As we now know, he was wrong on both these counts, though he could scarcely have foreseen quantum physics or relativity theory. It is premature to say that McGinn has won the day, and it is likely that philosophers and neuroscientists will continue to battle on for a good while yet. Yet if he is right – that there is a perfectly good, naturalistic solution to the problem, only we can never find it – maybe they should be looking for a better way to pass their time.
© Roger Caldwell 2006
Roger Caldwell is a poet, philosopher and literary critic who lives in Essex. His book of philosophical poetry, This Being Eden, was published by Peterloo Press.
The books referred to in this article are:
Daniel C. Dennett, Sweet Dreams – Philosophical Obstacles to a Science of Consciousness (MIT Press 2005)
John R. Searle, Mind – A Brief Introduction (Oxford University Press 2004)
Colin McGinn, Consciousness and its Objects (Clarendon Press 2004)