Anil Mitra PHD, COPYRIGHT © 1996, REFORMATTED May 2003
Document status: May 21, 2003
No further action needed for Journey in Being
No action needed for studies in consciousness since this document is superseded by Review of works by John Searle and David Chalmers
Maintained out of interest
The article outlines philosophical issues that surround the putative biological problem of explaining how consciousness arises in the brain - and then reviews recent books by Francis Crick, Daniel Dennett, Gerald Edelman [two books], Roger Penrose, and Israel Rosenfield. The following books are reviewed:
The Astonishing Hypothesis: The Scientific Search for the Soul, Francis Crick
Consciousness Explained, Daniel C. Dennett
The Remembered Present: A Biological Theory of Consciousness, Gerald Edelman
Bright Air, Brilliant Fire: On the Matter of the Mind, Gerald Edelman
Shadows of the Mind: A Search for the Missing Science of Consciousness, Roger Penrose
Familiar, and Forgotten: An Anatomy of Consciousness,
Quotes 1 through 7, which follow, are from the philosophical preliminary. The remaining Quotes 8 through 12 are from the review portion of Searle’s essay. Interwoven with the quotes and comments are my observations. They are numbered 1 thruugh 7 in approximate correspondence with the Quotes 1 through 7
“The most important problem in the biological sciences is... How exactly do neurobiological processes in the brain cause consciousness.”
A number of approaches lead to the conclusion that brain processes cause consciousness: the effects of injury to specific parts of the brain; the correlates between mental activities [such as perception, thought, emotion] and neurobiological activities; and the formation by the brain of “the body image”. The following quote occurs later in the second part of the article in reviewing Rosenfield [and will be repeated in its place in the sequence of quotes]:
“The brain forms an image of the entire body. And when we feel pains or any other sensations in the body, the actual occurrence of the experience is in the body image
“That we experience bodily sensations in the body image is most obvious in the case of phantom limbs... a patient may continue to feel pain in his toe even after his entire limb has been amputated.”
Now, I do not want to deny the importance of the idea that consciousness or experience arises in the brain [or is “caused” by the brain]. There are two reasons that I regard this stark form of materialism as important:  it provides clues to the whole picture and  it challenges me to sharpen my own views which include but are not restricted to alternate ways of thinking. Here, however only some brief challenges to the idea that mind or mental processes or mental function is caused by or arises in or is ontologically secondary to matter and material processes
Anything that is empirical is contingent: matter as the seat of mind, death... therefore even if mind is seen to arise in matter, it does not follow, except in pragmatic materialism, that all mind arises in matter
Ultimately: if we consider the claim “mind, consciousness arises in the brain”, we can ask: what causes brains to exist and body images to form: ontogenetically, proximately in epigenesis and from the relatively immediate and local environment and phylogenetically and ultimately [in the biological sense] from the earth and its history and even from existence... and all of this within a standard material or cosmological framework
In the here and now: from the diffusion of consciousness among the elements of being [see my essay for details]... is not this diffusion the trace of the ultimate in the present, and if it is vague, is this not only so relative to the stark elements of consciousness but not to the primal ground: the body and its unconscious including the mental: including the “seen but not recognized”
The existence of alternate points of view: idealism, realism and realistic idealism [including graded realism]... programmatically and have some clear-headed thinking to do before I define my position
Now, the idea that the occurrence of all experience - sensations, stream of consciousness, etc. - occurs in the body image and that the “brain forms an image of the entire body” is a powerful argument for the thesis that “neurobiological processes in the brain cause consciousness”
Therefore I propose to drive a wedge into any absolute and final notion of the two-part idea  the brain creates the body image, and  all experience occurs in the body image. Of course this is not to deny the utility of this idea as an important component of any complete explanation of the source of consciousness
Preliminarily, let us consider “phantom” pain. Suppose the source of such pain occurs at some point between the limb-stub and the brain. Something causes a tweaking of the nerve or an excitation of a neuron. Physically a neural impulse is received or occurs in the brain. There is the experience of pain... and no doubt interpretation of the “sensation” also enters into the registration of pain
Searle will say:
“It might sound as if phantom limb pains were some extremely peculiar oddity, but in fact, many of us have a version of the phantom limb in the form of sciatic pains... what exactly is going on in [a patient’s] leg that corresponds to his pain? Exactly nothing! ... the sciatic nerve in the spine is stimulated and this triggers neuron firings in his brain which give him the experience of feeling a pain in his leg...” and
“in a sense all our bodily sensations are phantom body experiences, because the match between where the sensation seems to be and the actual physical body is entirely created in the brain.”
Thus, while phantom limb phenomena and sciatica reinforce arguments for the body image, they also show that the body image can be mistaken. This is not a serious problem, nor is it an objection to the body image; but it needs to be noted. The body image itself is one source of somatic hallucination
More seriously: consider  the reflex arc and  the separation of consciousness within the individual “I” leading to multiple but diffuse and apparently discrete centers of consciousness within the person. This is the wedge. The concept of multiple centers of consciousness in the individual in total or partial separation stand against the completeness of brain-body image as the source-manifold of all experience. Or, we could perhaps say that the brain itself is more distributed than we think it to be... or, more precisely, we could talk of a functional-conceptual Brain vs. the organic brain
“All of our conscious life is caused by these lower level processes but we have only the foggiest idea of how it all works... why don’t the relevant specialists... figure out how it works? Why should it be any harder than finding out the causes of cancer? But there are a number of problems raised by the brain sciences even harder to solve. Some of the difficulties are practical.”
Searle now comments on the number of neurons [estimated 1011] and the number of interconnections per neuron [100 to many 10-thousands] and the difficulty of experimenting on live subjects: you and me. He adds:
“In addition to the practical difficulties, there are several philosophical and theoretical obstacles and confusions that make it hard to pose and answer the right questions. For example, the commonsense way in which I have just posed the question: How do brain processes cause consciousness? is already philosophically loaded.”
He wants to set the stage before discussing the latest work, “by clarifying some of the issues and correcting what seem to me to be the worst historical mistakes.”
Consciousness so defined switches off and on.”
“One issue can be dealt with swiftly. There is a problem that is supposed to be difficult but does not seem very serious to me and that is the problem of defining ‘consciousness’ “... and:
“It does not seem to me at all difficult to give a commonsense definition of the term: ‘consciousness’ refers to those states of sentience and awareness that typically begin when we awake from a dreamless sleep and continue until we go to sleep again or fall into a coma or die, or otherwise become ‘unconscious’. Dreams are a form of consciousness, though of course quite different from full waking states. Consciousness so defined switches off and on.”
This is an example in which the contingent is made necessary...This is legitimate from some practical points of view, useful in terms of providing a necessary practical philosophical complement to scientific-empirical brain research. But we need to have in the back of our minds - at least - that the ultimate may be quite different. This is valuable of course from metaphysical, personal and religious-spiritual perspectives that some practical persons minimize; but: even the ultimate has practical implications. See my essay for details on relations between immediate and ultimate issues
“The first serious problem derives from intellectual history... Descartes and Galileo made a sharp distinction between the physical reality described by science and the mental reality of the soul..
“...But this dualism has become an obstacle in the twentieth century, because it seems to place consciousness and other mental phenomena outside the ordinary physical world and thus outside the realm of natural science.”
Even scientists who admit scientific discussion of consciousness may be blocked by the ordinary language of their intuition, and in which they talk about science... I have for many years attempted to recognize the traces of dualistic thinking and language in my own experience and the idea of mind as alien to science and yet, especially in conversation and other interaction with others - the world of work, I experience the return of the dualist paradigm
As noted by Searle, the Cartesian dualism has theological origins and ongoing theological biases. It also has a socio-economic basis; and of course, through history, the sacred and the secular mesh in their broad relations
“But even if we treat consciousness as a biological phenomenon and thus as part of this ordinary physical world, there are still many mistakes to avoid. One I just mentioned: if brain processes cause consciousness, then it seems to many people that there must be two different things: brain processes as causes and conscious states as effects, and this seems to imply dualism. This second mistake derives in part from a flawed conception of causation. In our official theories we suppose that all causal relations must be between discrete events ordered serially in time..
“Certainly, many cause and effect relations are like that, but by no means all... think of the solidity of the table: it is explained causally by the behavior of the molecules of which the latter is composed. But the solidity of the table is not an extra event, it is just a feature of the table... By the way, this analysis - that brain processes cause consciousness but that consciousness itself is a feature of the brain provides us with a solution to the traditional mind-body problem, a solution which avoids both dualism and materialism, at least as these are traditionally conceived.”
Now Searle identifies a third difficulty: that of explaining the subjective, qualitative states that we possess intimately and privately in terms of the publicly observable, objective phenomena of brain phenomena. The private, internal, qualitative states are sometimes called - as Searle notes - qualia. He now states:
The following observations regard partition of the problem of consciousness into  the philosophical problem of the origin of qualia in matter, and  the scientific problem of how specific qualia and, more generally, the structure and categories of mental process arise in the brain
“Among the interesting differences in the accounts of consciousness given by the writers under review are their various divergent ways of coming to terms - or sometimes failing to come to terms - with the problem of qualia.”
As Searle will point out, the problem of qualia is sometimes considered to be a side issue, but in fact it is not: it is the problem of consciousness
Now in fact this problem can be broken down into two parts:  the general problem of the origin of qualia in matter [assuming of course that qualia do so arise] and  how the specific qualia: a color, a feeling of warmth, perception of a scene, thinking... arise from specific processes [or sets of processes] in specific parts [or sets of parts] of the brain. Searle has identified these two parts but I don’t think he claimed the partition of the problem into the two parts. Part  is general, philosophical. And it is one reason to consider idealist versions of metaphysics. Part  is scientific, neurobiological, detailed
Further along in the article, toward the end of his review of Gerald Edelman’s work, Searle seems to me to equate part  with the problem of qualia even though, generally, he clearly and definitely recognizes the difficulty of part 
My essay includes further consideration of what may be called the philosophical problem of qualia. I argue that matter, by definition, cannot in principle explain qualia. I consider philosophically and historically what any definition of matter must be - what is the essence of such a definition [a different question than: what is the essence of matter?]
However, the philosophical difficulty in no way limits answers to part . Thus, although the scientific explanation is far from complete, the difficulties - unless there is some philosophical issue I have overlooked - are practical. This does not mean that the practical difficulties can or will be resolved by us, or anyone; nor will a proximate material explanation end the matter, for we also want ultimate and mental explanations [and these in turn yield new material issues]
Some of the other authors under review agree, but for different reasons, that qualia cannot be explained scientifically. And thus, in some cases, they see some inherent practical limitation that I don’t see
“A fourth difficulty is peculiar to our intellectual climate right now and that is the urge to take the computer metaphor of the mind too seriously... There are different versions of the computational theory of the mind. The strongest one is...: the mind is just a computer program. There is nothing else there. This view I call Strong Artificial Intelligence [Strong AI for short] to distinguish it from the view that the computer is a useful tool in doing simulations of the mind... This more cautious view I call Weak AI.”
“... Strong AI can be refuted swiftly,..
“... The Chinese Room Argument - as it has come to be called - has a simple three-step structure
1. Programs are syntactical
2. Minds have a semantics
3. Syntax is not the same as, nor by itself sufficient for, semantics
“Therefore programs are not minds. QED
“It now seems to me that the argument, if anything, concedes too much to strong AI, in that it concedes that the theory was at least false. I now think that it was incoherent, and here is why
“The upshot is that Strong AI, which prides itself on its “materialism” and on the view that the brain is a machine, is not nearly materialistic enough.”
Searle’s contention - and I agree within a materialist paradigm - is that the brain is an [organic] machine whereas a computation is an abstract mathematical process that exists relative to conscious observers and interpreters. He continues:
“This is a different argument from the Chinese Room, but it is deeper. The Chinese Room Argument showed that semantics is not intrinsic to syntax; this shows that syntax is not intrinsic to physics
“I reject Strong AI but accept Weak AI. Of the authors under review Dennett holds a version of Strong AI, Roger Penrose rejects even Weak AI. He thinks that the mind cannot even be simulated on a computer. Gerald Edelman accepts the Chinese Room Arguments against Strong AI and presents some other arguments of his own, but he accepts Weak AI, indeed he makes powerful use of computer models in his research on the brain, as we will see
“To summarize the general position, then, of how brain research can proceed in answering the questions that bother us: the brain is an organ like any other. Consciousness is caused by lower level neuronal processes in the brain and is itself a feature of the brain. Because it is a feature that emerges from certain neuronal activities, we can think of it as an ‘emergent property’. Computers play the same role in studying the brain that they play in any other discipline. They are immensely useful devices for studying brain processes. But the simulation of mental states is no more a mental state than the simulation of an explosion is an explosion.”
Searle now turns to review the recent books on consciousness
“The astonishing hypothesis, on which the book is based, is
“that ‘You,’ your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behavior of a vast assembly of nerve cells and their associated molecules
“There are two parts to Crick’s astonishment. The first is that all of our mental life has a material existence in the brain - and that is indeed not very astonishing - but, more interestingly, the specific mechanisms, in the brain that are responsible for our mental life are neurons and their associated molecules, such as neurotransmitter molecules. I, for one, am always amazed by the specificity of biological systems, and in the case of the brain, the specificity takes a form you could not have predicted just from knowing what it does. If you were designing an organic machine to pump blood you might come up with something like a heart, but if you were designing a machine to produce consciousness, you would think of a hundred billion neurons?
“Crick is not clear about distinguishing causal explanations of consciousness from reductionist eliminations of consciousness. The passage I quoted above makes it look as if he is denying that we have conscious experiences in addition to having neuron firings. But I think that a careful reading of the book shows that what he means is something like the claim that I advanced earlier: all of our conscious experiences are explained by the behavior of neurons, and are themselves emergent properties of the system of neurons
“The fact that the explanatory part of Crick’s claim is standard neurobiological orthodoxy today, and will astonish few of the people who are likely to read the book, should not prevent us from agreeing that it is amazing how the brain does so much with such a limited mechanism. Furthermore, not everyone who works in this field agrees that the neuron is the essential functional element. Penrose believes neurons are already too big, and he wants to account for consciousness at a level of much smaller quantum mechanical phenomena. Edelman thinks neurons are too small for most functions and regards the functional elements as ‘neuronal groups’
“How does the neuron work? A neuron is a cell like any other, with a cell membrane and a central nucleus. Neurons differ, however, in certain remarkable ways, both anatomically and physiologically, from other sorts of cells. There are many different types of neuron, but the typical garden-variety neuron has on it a longish, thread-like protuberance called an axon growing out of one side, and a bunch of spiny, somewhat shorter, spiky threads called dendrites on the other side. Each neuron receives signals through its dendrites..
“Now what is astonishing is this: as far as our mental life is concerned, that story I just recounted about neurons is the entire causal basis of our conscious life
“Crick is generally hostile to philosophers and philosophy, but the price of having contempt for philosophy is that you make philosophical mistakes. Most of these do not seriously damage his main argument, but they are annoying and unnecessary. I will mention three philosophical errors that I think are really serious
“First, he misunderstands the problem of qualia. He thinks it is primarily a problem about the way one person has knowledge of another person’s qualia..
“Second, Crick is inconsistent in his account of the reduction of consciousness to neuron firings. He talks reductionist talk, but the account he gives is not at all reductionist in nature. Or, rather, there are at least two senses of ‘reduction’ that he fails to distinguish. In one sense, reduction is eliminative... But in another sense of reduction we explain a phenomenon but do not get rid of it. Thus the solidity of an object is entirely explained by the behavior of molecules, but this does not show that no object is really solid or that there is no distinction between, say, solidity and liquidity. Now Crick talks as if he wants an eliminative reduction of consciousness but in fact the direction of his book is toward a causal explanation..
“The puzzle is that Crick preaches eliminative reductionism when he practices causal emergentism. The standard argument in philosophy against an eliminative reduction of consciousness is that even if we had a perfect science of neurobiology there would still be two distinct features, the neurobiological pattern of neuron firings and the feeling of pain, for example..
“Third, Crick is unclear about the logical structure of the explanation he is offering, and even on the most sympathetic reading it seems to be inconsistent. I have so far been interpreting him as seeking a causal explanation of visual consciousness and his talk of ‘mechanism’ and ‘explanation’ supports that interpretation. But he never says clearly that he is offering a causal explanation of how brain processes cause visual awareness. His preferred way of speaking is to say that he is looking for the ‘neural correlates’ of consciousness. But on his own terms ‘neural correlates’ cannot be the right expression. First, a correlation is a relation between two different things, but a relation between two things is inconsistent with the eliminative reductionist line that Crick thinks he is espousing. On the eliminative reductionist view there should be only one thing, neuron firings. Second, and more important, even if we strip away the reductionist mistake, correlations by themselves would not explain anything. Think of the sight of lightning and the sound of thunder. The sight and sound are perfectly correlated, but without a causal theory, you do not have an explanation
“Furthermore, Crick is unclear about the relation between the visual experiences and the objects in the world that they are experiences of. Sometimes he says the visual experience is a ‘symbolic description’ or ‘symbolic interpretation’ of the world. Sometimes he says the neuronal processes ‘represent’ objects in the world. He is even led to deny that we have direct perceptual awareness of objects in the world, and for that conclusion he uses a bad argument right out of seventeenth-century philosophy. He says that since our interpretations can occasionally be wrong, we have no direct knowledge of objects of the world. This argument is in both Descartes and Hume, but it is a fallacy... In the standard case, such as when I look at my watch, I really see the real watch. I do not see a ‘description’ or an ‘interpretation’ of the watch..
“I believe that Crick has been badly advised philosophically, but fortunately you can strip away the philosophical confusions and still find an excellent book..
“What, then, is Crick’s solution to the problem of consciousness? One of the most appealing features of Crick’s book is his willingness, indeed eagerness, to admit how little we know. But given what we do know he makes some speculations. To explain his speculations about consciousness, I need to say something about what neurobiologists call ‘the binding problem’. We know that the visual system has cells and indeed regions that are especially responsive to particular features of objects such as color, shape, movement, lines, angles, etc. But when we see an object we have a unified experience of a single object. How does the brain bind all of these different stimuli into a single, unified experience of an object? The problem extends across the different modes of perception. All of my experiences at present are part of one big unified conscious experiences [Kant, with his usual gift for catchy phrases, called this ‘the transcendental unity of apperception’]..
“Crick says the binding problem is ‘the problem of how these neurons temporarily become active as a unit’. But that is not the binding problem; rather it is one possible approach to solving the binding problem... Neurons responsive to shape, color, and movement for example, fire in synchrony in the general range of forty firings per second [forty Hertz]. Crick and his colleague Christof Koch take this hypothesis a step further and suggest that maybe synchronized neuron firing in this range [roughly forty Hertz, but as low as thirty-five and as high as seventy-five] may be the ‘brain correlate’ of visual consciousness..
“Crick has written a good and useful book. He knows a lot, and he explains it clearly. Most of my objections are to his philosophical claims and presuppositions, but when you read the book you can ignore the philosophical parts and just learn about the psychology of vision, and brain science. The limitations of neurobiological parts of the book are the limitations of the subject right now: we do not know how the psychology of vision and neurophysiology hang together, and we do not know how brain processes cause consciousness, whether visual consciousness or otherwise.”
“Of the books under review perhaps the most ambitious is Penrose’s Shadows of the Mind. This is a sequel to his earlier The Emperor’s New Mind and many of the same points are made, with further developments and answers to objections to his earlier book. The book divides into equal parts. In the first he uses a variation of Gödel’s famous proof of the incompleteness of mathematical systems to try to prove that we are not computers and cannot even be simulated on computers. Not only is Strong AI false, Weak AI is too. In the second half he provides a lengthy explanation of quantum mechanics with some speculations on how a quantum mechanical theory of the brain might explain consciousness in a way that he thinks classical physics cannot possibly explain it. This, by the way, is the only book I know where you can find lengthy and clear explanations of two of the most important discoveries of the twentieth century, Gödel’s incompleteness theorem and quantum mechanics
“I admire Penrose and his books enormously. He is brash, enthusiastic, courageous, and often original... My main disagreement is that his use of Gödel’s proof does not seem to me to succeed, and I want to say why it does not..
“That is, Penrose’s argument rests on what we can know and understand, but it is not a requirement of computational cognitive science that people be able to understand the programs they are supposed to be using to solve cognitive problems
“This objection was made by Hilary Putnam in his recent review of Penrose in The New York Times, and Penrose responded with an indignant letter [in New York Times Book Review, November 20, 1994]..
“Penrose’s discussion is always about the conscious thought processes of mathematicians when they are proving mathematical results, and he wants to know whether theorem-proving algorithms can account for all of their successes. They can’t; but that is not the question at issue in computational cognitive science, at least not as far as Weak AI is concerned. The aim is not to get an algorithm that people are trying to follow, but rather one which accurately describes what is going on inside them... Nothing whatever in Penrose’s arguments militates against a computational model of the brain, so construed..
“To summarize this point: Penrose fails to distinguish algorithms that mathematicians are consciously [or unconsciously, for that matter] following, in the sense of trying to carry out the steps in the algorithm, from algorithms that they are not following but which accurately simulate or model what is happening in their brains when they think. Nothing in his argument shows that the second kind of algorithm is impossible. The real objection to the second kind of algorithm is not one he makes. It is that such computer models don’t really explain anything, because the algorithms play no causal role in the behavior of the brain. They simply provide simulations or models of what is happening..
“In the second part of the book, Penrose summarizes the current state of our knowledge of quantum mechanics and tries to apply its lessons to the problem of consciousness..
“Here is the hypothesis [Penrose] presents:
“On the view that I am tentatively putting forward, consciousness would be some manifestation of this quantum-entangled internal cytoskeletal state and of its involvement in the interplay... between quantum and classical levels of activity
“...The problem with these speculations is that they do not adequately speculate on how we might solve the problem of consciousness. They are of the form: If we had a better theory of quantum mechanics and if that theory were noncomputable, then maybe we could account for consciousness in a noncomputational way. But how?..
“I have not explored the deeper metaphysical presuppositions behind his entire argument. He comes armed with the credentials of science and mathematics, but in fact he is a classical metaphysician, a self-declared Platonist. He believes we live in three worlds, the physical, the mental, and the mathematical... I will simply assert the following without argument: we live in one world, not two or three or twenty-seven... Admiring Penrose and his work enormously, I conclude that the chief value of Shadows of the Mind is that from it you can learn a lot about Gödel’s theorem and about quantum mechanics. You will not learn much about consciousness.”
“...Similarly, Edelman wants to extend an account of the development of perceptual categories - categories ranging from shapes, color and movement to objects such as cats and dogs - into a general account of consciousness. The first idea central to Edelman is the notion of maps. A map is a sheet of neurons in the brain where the points on the sheet are systematically related to the corresponding points on a sheet of receptor cells..
“The second idea is his Theory of Neuronal Group Selection..
“The basic point is that the brain is not an instructional mechanism, but a selectional mechanism; that is, the brain does not develop by alterations in a fixed set of neurons, but by selection processes that eliminate some neuronal groups and strengthen others
“The third, and most important, idea is that of reentry. Reentry is a process by which parallel signals go back and forth between maps..
“So the result is that you get a unified representation of objects in the world even though the representation is distributed over many different areas of the brain. Different maps in different areas are busy signaling each other through the reentry pathways... what Edelman calls ‘global mapping’ and this allows the system not only to have perceptual categories and generalization but also to coordinate perception and action..
“When Edelman talks about perceptual categorization he is not talking about conscious perceptual experiences
“The question then is, how do we get from the apparatus I have described so far to conscious experiences? What more is needed?... It is essential to distinguish between ‘primary consciousness’, which is a matter of having what he calls imagery, by which he means simple sensations and perceptual experiences, and ‘higher-order consciousness’, which includes self-consciousness and language. In order to have primary consciousness in addition to the mechanisms just described, the brain needs at least the following:..
“1. It must have memory..
“2. The brain must have a system for learning. Learning for Edelman involves not only memory but also value, a way of valuing some stimuli over others..
“3. The brain also needs the ability to discriminate the self from the nonself..
“To get the full account of primary consciousness we have to add three more elements
“4. The organism needs a system for categorizing successive events in time, and for forming concepts
“5. A special kind of memory is needed. There must be ongoing interactions between system 4 and the systems described in 1, 2, and 3, in such a way as to give us a special memory system for values matched to past categories
“6. We need a set or reentrant connections between the special memory system and the anatomical systems that are dedicated to perceptual categorizations..
“The problem is the same one we encountered before: How do you get from all these structures and their functions to the qualitative states of sentience or awareness that all of us have, which some philosophers call ‘qualia’?... His answer to the problem of qualia in The Remembered Present seems to me somewhat different from the one in Bright Air, Brilliant Fire, but neither seems to me to be adequate. In The Remembered Present he says that science cannot tell us why warm feels warm and we should not ask it to. But it seems to me that is exactly what a neuroscience of consciousness should tell us: What anatomical and physiological features of the brain cause us to have consciousness at all, and which features cause which specific forms of conscious states..
“In Bright Air, Brilliant Fire, Edelman says we cannot solve the problem of qualia because no two people will have the same qualia and there is no way that science, with its generality, can account for these peculiar and specific differences..
“Though Edelman differs from Crick on many issues, they share the one basic conviction that drives their research. To understand the mind and consciousness we are going to have to understand in detail how the brain works.”
“Before discussing Dennett’s Consciousness Explained, I want to ask the reader to perform a small experiment to remind himself or herself of what exactly is at issue in theories of consciousness. Take your right hand and pinch the skin on your left forearm. What exactly happened when you did so? Several different sorts of things happened. First, the neurobiologists tell us that the pressure of your thumb and forefinger set up a sequence of neuron firings that began at the sensory receptors in your skin... A few hundred milliseconds after you pinched your skin, a second sort of thing happened... You felt a pain..
“This unpleasant sensation had a certain particular sort of subjective feel to it, a feel which is accessible to you in a way it is not accessible to others around you. This accessibility has epistemic consequences - you can know about your pain in a way that others cannot - but the subjectivity is ontological rather than epistemic. That is, the mode of existence of the sensation is a first-person or subjective mode of existence whereas the mode of existence of the neural pathways is a third-person or objective mode of existence; the pathways exist independently of being experienced in a way that pain does not. The feeling of the pain is one of the “qualia” I mentioned earlier
“Furthermore, when you pinched your skin, a third sort of thing happened. You acquired a behavioral disposition you did not previously have. If someone asked you, “Did you feel anything?” you would say something like, “Yes, I felt a mild pinch right here.” No doubt other things happened as well - you altered gravitational relations between your right hands and the moon, for example - but let us concentrate on these first three
“If you were asked what is the essential thing about the sensation of pain, I think you would say the second feature, the feeling, is the pain itself... The problem of consciousness in both philosophy and the natural sciences is to explain these subjective feelings. Not all of them are bodily sensations like pain. The stream of conscious thought is not a bodily sensation and neither are visual experiences. Yet both have the quality of ontological subjectivity that I have been taking about. The subjective feelings are the data that a theory of consciousness has to explain, and the account of the neural pathways that I sketched is a partial theory to account for the data. The behavioral dispositions are not part of the conscious experience, but they are caused by it
“The peculiarity of Daniel Dennett’s book can now be stated: he denies the existence of the data. He thinks there is no such thing as the second sort of entity, the feeling of pain. He thinks there are no such things as qualia, subjective experiences, first-person phenomena, or any of the rest of it..
“What really happens, according to Dennett, is that we have stimulus inputs, such as the pressure on your skin in my experiment, and we have dispositions to behavior, ‘reactive dispositions’ as he calls them. And in between there are ‘discriminative states’ that cause us to respond differently to different pressures on the skin, to discriminate red from green, etc., but the sort of state that we have for discriminating pressure is exactly like the state of a machine for detecting pressure... there are no such things as ‘inner feelings’. It is all a matter of third-person phenomena: stimulus inputs, discriminative states, and reactive dispositions..
“The main point of Dennett’s book is to deny the existence of inner mental states and offer an alternative account of consciousness, or rather what he calls ‘consciousness’... Dennett, however, does not begin on page one to tell us that he thinks conscious states...do not exist, and that there is nothing there but a brain implementing a computer program. Rather, he spends the first two hundred pages discussing questions which seem to presuppose the existence of subjective conscious states and proposing a methodology for investigating consciousness... It is not until after page 200 that you get his account of ‘consciousness’, and not until well after page 350 that you find out what is really going on
“The main issue in the first part of the book is to defend what he calls the ‘Multiple Drafts’ model of consciousness as opposed to the ‘Cartesian Theater’ model. The idea, says Dennett, is that we are tacitly inclined to think that there must be a single place in the brain where it all comes together, a kind of Cartesian Theatre where we witness the play of our consciousness. And in opposition he wants to advance the view that a whole series of information states are going on in the brain, rather like multiple drafts of an article. On the surface, this might appear to be an interesting issue for neurobiology: where in the brain are our subjective experiences localized? Is there a single locus or many? A single locus, by the way, would seem neurobiologically implausible, because any organ in the brain that must seem essential to consciousness... has a twin on the other side of the brain. But that is not what Dennett is driving at. He is attacking the Cartesian Theater not because he thinks subjective states occur all over the brain, but rather because he does not think there are any such things as subjective states at all..
“What is his alternative account? Not surprisingly, it is a version of Strong AI. In order to explain it I must first briefly explain four notions that he uses: von Neumann machines, connectionism, virtual machines, and memes. A digital computer, the kind you are likely to buy in a store today... is called a serial computer, and because the initial designs were by John von Neumann,... it is sometimes called a von Neumann machine. Recently there have been efforts to build machines that operate in parallel, that is with several computational channels working at once and interacting with each other. In physical structure these are more like human brains. They are not really much like brains, but certainly they are more like brains than the traditional von Neumann machines..
“Another notion Dennett uses is that of a ‘virtual machine’. The actual machine I am now working on is made of actual wires, transistors, etc.; in addition, we can get machines like mine to simulate the structure of another type of machine. The other machine is not actually part of the wiring of this machine but exists entirely in the patterns of regularities that can be imposed on the wiring of my machine. This is called the virtual machine
“The last notion Dennett uses is that of a ‘meme’. This notion is not very clear. It was invented by Richard Dawkins to have a cultural analogue to the biological notion of a gene... According to Dawkins’s definition a meme is..
“a unit of cultural transmission, or a unit of imitation ... Examples of memes are tunes, ideas, catchphrases, clothes fashions, ways of making pots or of building arches. Just as genes propagate themselves in the gene pool by leaping from body to body via sperm or eggs, so memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation
“I believe the analogy between gene and ‘meme’ is mistaken. Biological evolution proceeds by brute, blind, natural forces. The spread of ideas and theories through ‘imitation’ is typically a conscious process directed toward a goal. It misses the point of Darwin’s account of the origin of the species to lump the two sorts of processes together
“On the basis of these four notions, Dennett offers the following explanation of consciousness:
“Human consciousness is itself a huge collection of memes [or more exactly, meme-effects in brains] that can best be understood as the operation of a ‘von Neumannesque’ virtual machine implemented in the parallel architecture of a brain that was not designed for any such activities
“In other words, being conscious is entirely a matter of implementing a certain sort of computer program or programs in a parallel machine that evolved in nature..
“The extreme anti-mentalism of his views has been missed by several of Dennett’s critics, who have pointed out that, according to his theory, he cannot distinguish between human beings and unconscious zombies who behave exactly as if they were human beings..
“His claim is that...there is no difference between us and machines that lack conscious states in the sense I have explained... In one of his several discussions of zombies, he considers whether there is any difference between human pain and suffering and a zombie’s pain and suffering..
“Why should a ‘zombie’s’ crushed hopes matter less than a conscious person’s crushed hopes? There is a trick with mirrors here that should be exposed and discarded. Consciousness, you say, is what matters, but then you cling to doctrines about consciousness that systematically prevent us from getting any purchase on why it matters. Postulating special inner qualities that are not only private and intrinsically valuable, but also unconfirmable and uninvestigatable is just obscurantism
“The rhetorical flourishes here are typical of the book, but to bring the discussion down to earth, ask yourself: When you performed the experiment of pinching yourself, were you ‘postulating special inner qualities’ that are ‘unconfirmable and uninvestigatable’? Where you being ‘obscurantist’? And most important, is there no difference at all between you who have pains and an unconscious zombie that behaves like you but has no pains or any other conscious states?..
“Dennett’s book is unique among the several under discussion here in that it makes no contribution to the problem of consciousness but rather denies that there is any such problem in the first place..
“I regard Dennett’s denial of the existence of consciousness not as a new discovery or even as a serious possibility but rather as a form of intellectual pathology. The interest of his account lies in figuring out what assumptions could lead an intelligent person to paint himself into such a corner..
“Scientific objectivity, according to Dennett’s conception, requires ‘the third-person point of view’. At the end of his book, he combines this view with verificationism - the idea that only things that can be scientifically verified really exist. These two theories lead him to deny that there can exist any phenomena that have a first-person ontology. That is, his denial of the existence of consciousness derives from two premises: scientific verification always takes the third-person point of view, and nothing exists which cannot be verified by scientific verification so construed. This is the deepest mistake in the book, and it is the source of most of the others, so I want to end this discussion by exposing it
“We need to distinguish the epistemic sense of the distinction between the first- and the third-person points of view [i.e., between the subjective and the objective] from the ontological sense. Some statements can be known to be true or false independently of any prejudices or attitudes on the part of observers. They are objective in the epistemic sense... Some entities, mountains for example, have an existence which is objective in the sense that it does not depend on any subject. Others, pain for example, are subjective in that their existence depends on being felt by a subject. They have a first-person or subjective ontology
“Now here is the point. Science does indeed aim at epistemic objectivity... But epistemic objectivity of method does not require ontological objectivity of subject matter... Dennett has a definition of science which excludes the possibility that science might investigate subjectivity, and he thinks the third-person objectivity of science forces him to this definition. But that is a bad pun on ‘objectivity’. The aim of science is to get a systematic account of how the world works. One part of the world consists of ontologically subjective phenomena. If we have a definition of science that forbids us from investigation that part of the world, it is the definition that has to be changed and not the world.”
“Israel Rosenfield’s book is the shortest and apparently the most unassuming of the books under review, but it is quite ambitious in its aims. On the surface the book consists mostly of a series of case histories describing various forms of neural damage that people have suffered and the consequences for their mental life and consciousness..
“Consciousness arises from the ‘dynamic interrelations of the past, the present, and the body image’..
“The continuity of consciousness derives from the correspondence which the brain establishes from moment to moment with events in space and time. The vital ingredient in consciousness is self-awareness..
“One of the most remarkable things about the brain is its capacity to form what neurobiologists call ‘the body image’. To understand this, remember when I asked you to pinch your left forearm. When you did so, you felt a pain. Now, where exactly does the event of your feeling the pain occur? Common sense and our own experience tell us that it occurs in our forearm exactly in the area of the skin that we have been pinching. But in fact, that is not where it occurs. It occurs in the brain. The brain forms an image of our entire body. And when we feel pains or any other sensations in the body, the actual occurrence of the experience is in the body image in the brain..
“I believe the most important implication of his book for future research is that we ought to think of the experience of our own body as the central reference point of all forms of consciousness
“I said at the beginning of the first of these two articles that the leading problem in the biological sciences is the problem of explaining exactly how neurobiological processes cause conscious experiences. This is not Rosenfield’s direct concern and none of the books under review provides an adequate answer to that question; but Crick, Edelman, and Penrose, in their quite different ways, are at least on the right track. They are all trying to explain how the physical matter in our head could cause subjective states of sentience or awareness. We have a long way to go, but with the philosophical ground cleared of various confusions such as Strong AI, it is at least possible to state clearly what the problem is and to work toward its solution