Biophysics of Consciousness: A Foundational Approach R. R. Poznanski, J. A. Tuszynski and T. E. Feinberg Copyright 2017 World Scientific, Singapore. FOREWORD: ADDRESSING THE HARD PROBLEM OF CONSCIOUSNESS John R. Searle Department of Philosophy 314 Moses Hall 2390 University of California Berkeley, CA 94720-2390, USA The hard problem of consciousness is concerned with what I take to be the leading problem in the biological sciences today. Indeed, the case could be made that it is the leading problem in science in general. To put the problem at its most succinct: How exactly do neurobiological processes in the brain cause consciousness? This is sometimes called the hard problem to suggest that it is a different problem in kind from such other neurobiological pro blems as for example, how does the reflex arc work, what is the exact role of neurotransmitters in action potentials? I will now explain the problem in a way that will enable us to expand its formulation to include more aspects. First we will have to answer the question, what is consciousness? Consciousness is sometimes said to be hard to define but I think if we are just talking about a common sense definition that identifies the target of the discussion and not a scientific definition of the sort that typically comes at the end of the investigation, then consciousness is not hard to define. Here is the definition. By consciousness we mean all of our states of feeling or sentience or awareness. These typically begin in the morning when we wake from a dreamless sleep and they go on all day until we once again fall asleep, or otherwise become unconscious. xiii
xiv Foreword: Addressing the Hard Problem of Consciousness On this definition dreams are a form of consciousness. Consciousness so defined only exists insofar as experienced by human or animal subjects and we can say therefore it has a first person or subjective ontology (where ontology just means the mode of existence). What exactly is the relation between consciousness so defined and the brain? Well opinions differ about that and indeed it is the traditional mind body problem. But I think in general outline, we know enough about how the world works to state the general features of the answer to the question. All of our conscious states without exception are caused by lower level neuronal processes in the brain. The textbooks typically assume that the neuron is the basic functional unit but for all we know it may be something higher than the level of individual neurons, such as whole maps or clouds of neurons, or according to some theorists, it may be something lower such as microtubules within the neuron. But in any case the neuron is a distinctive feature of the brain and it seems reasonable to suppose that it plays a special role in the creation of consciousness. If consciousness is entirely caused by neuron firings then what exactly is the status of consciousness? What is its form of existence? And here again I think the answer is obvious. Consciousness caused by neuron firings is realized in the system of neurons. Just as, for example the liquid or solid behavior of the body of water in front of me is causally explained by the behavior of the H 2 O molecules, but liquidity and solidity are not some extra juice or substance squirted out by the molecules, they are just the conditions that the system of molecules is in; in exactly that same sense I want to say that consciousness is a condition of the neuronal system. The analogy only works so far because of course we are perfectly happy to reduce solidity and liquidity to features of molecular behavior in a way that we are reluctant to make a similar reduction of consciousness, precisely because conscious ness has a subjective or first person ontology, unlike these other features which have an objective or third person ontology. So that is in broad outline both a solution to the mind body problem and a general description of the relationships between consciousness and the brain. I call this view biological naturalism because it is based on the assumption that the mind is a natural biological phenomenon that is as much a part of nature as photosynthesis, lactation or digestion, but at the same time the right level to discuss it is the level of biological processes and not for example, the level of sub-atomic physics, or the level of social structures. I think biological naturalism is exactly right but it raises a number of problems of its own. On this account, consciousness is a natural biological phenomenon like photosynthesis or digestion but it
Foreword: Addressing the Hard Problem of Consciousness xv differs from these other biological phenomena in several respects, perhaps most importantly because it has a first person ontology. The whole discussion of the relation of consciousness and the brain has such a sordid and confused history and it is very hard for us to overcome that history completely. Here in very brief outline are the two main elements of the history: (1) The first called dualism says that consciousness is not a part of the physical world in the way that I have described it, but it belongs to some separate ontological realm. Consciousness on the traditional view is not a feature of the brain at all, it is a feature of the soul and the soul is not a part of the brain or any other phenomenon in the physical world. The soul has a completely immaterial, non-physical existence. This view has been incredibly powerful for millennia but I think it is hopelessly inadequate, and I do not have the space to expose its inadequacy here but I will assume that it is inadequate. (2) The second view, which is almost as bad, takes itself to be a denial of dualism but in fact it accepts the worst mistake of dualism. It begins by saying that consciousness as I have defined it is not a part of the physical world but either it does not exist at all, or if it does exist it must be reducible to some feature of the physical world such as behavior, neuron firings, computer programs, etc. This view is sometimes called scientific materialism or materialist monism. But it is almost as confused as the dualism it is designed to replace because it denies the obvious fact that consciousness as defined really does exist as part of the physical, biological world. Does anyone doubt this? We are all conscious pretty much all of our waking lives and furthermore, consciousness exists with this irreducible first person ontology. For any conscious state there is something that it feels like to be in that conscious state. And this what it feels like feature is always a feature of the individual who is conscious, who has the conscious feelings. So given these twin mistakes, the whole history is strewn with the dead bodies of mistaken theories. I do not have much space but I will list five of the most outrageous mistaken theories. (1) Substance dualism. This is the view that says we are identical with our souls and our souls are temporarily attached to our bodies, but the souls have no material existence. I find it hard to take this view seriously, but as I said earlier it has been incredibly influential.
xvi Foreword: Addressing the Hard Problem of Consciousness (2) Property dualism. This view is not quite as bad but it is pretty bad. It says that there are not two different kinds of substances but two metaphysically different kinds of properties, the physical and the mental. Mental properties are not a part of the physical world, so this view immediately has the result that our mental life can have no causal effect. On this view called epiphenomenalism, no human being in the history of the world ever drank because she was thirsty or ate because he was hungry, or raised his arm because he wanted to raise his arm. This view is again, I think not worth discussing but it survives to this very day in various confused philosophical theories. (3) Materialist reductionism. On this view there really is no such thing as conscious phenomena as I have defined them. There are just third person phenomena. There is no such thing as irreducible ontological subjectivity. This view denies the very data that gets the subject going in the first place. (4) Behaviorism. This view says consciousness does exist but it is really something else. It is really just behavior or dispositions to behavior. This view makes the same mistake as reductionist materialism, it just substitutes behavior for matter. But of course we all know from our own case that feeling of pain is one thing and emitting pain behavior, such as saying Ouch!, is something else. You can have one without the other. You can have the pain without the pain behavior, and you can have the pain behavior without the pain. Behaviorism is so obviously false that it seems literally incredible that it should have been so influential for so long. The reason for its influence, is that it seems somehow more scientific than granting the obvious fact that we are all conscious and our consciousness is not reducible to something else. (5) Computationalism. A view that has recently become influential is the idea that consciousness is really just a computer program or set of computer programs running in our brains. On this view, the mind is to the brain as the program is to the hardware. This view is obviously false. I refuted it over 30 years ago with the so-called Chinese Room Argument and I will not repeat the details here, just state the obvious point. The computer program is defined formally or syntacti cally. To put it slightly more technically, the notion same implemented program defines an equivalence class that is specified completely independently of the hardware realization. But we know independently that the syntax of the computer program is not by itself
Foreword: Addressing the Hard Problem of Consciousness xvii sufficient for the semantics, or the mental content, of an actual mental life whether conscious or unconscious. I proved this with the Chinese Room Argument where a person locked in a room could answer questions in Chinese simply by following the steps of the program even though he understood not a word of Chinese, either the questions or the answers. The syntax of the program was sufficient for his behavior but it did not produce the semantics of actual human cognition. There are various other reductive theories out there also equally false. Currently there is an information theoretic view but it is, I believe, as confused as the views that I have refuted here. Well if consciousness just is a biological process in the same sense as digestion or photosynthesis, then why do not we get busy and give a scientific explanation of consciousness? I think in fact this is the right approach and we are making progress but it is more difficult than many people ever expected it would be, and I want to explain why. In the standard method in sciences you go through three stages. First you find a correlate of the phenomenon that you are seeking to explain. The correlate of consciousness is called the neuronal correlate of consciousness or simply the NCC. Second, you perform the usual tests to figure out if the correlate is a causal correlation and you do this by withholding the NCC and seeing if you stop con sciousness and resuming the NCC to see if you can restart consciousness. And third, you try to get a theory that explains why these phenomena have these effects. These are the stages by which we have for example come to understand heredity or come to understand the germ theory of disease. Why is it any different for consciousness? In fact I do not think it is any different. I think this is the right way to proceed but if progress has been slow, why? The main reason is that our existing research techni ques for the most part are either matters of imaging, for example, where you image processes in the brain that are going on whenever a certain state of consciousness occurs, or they are single cell recordings, where you track the neuron firing of a single neuron in the brain. The results from these two methods are immensely impressive but they still have not given a solution to consciousness. Why not? I do not know, but here is one speculation. The problem with consciousness is not at the level of indi vidual neurons and it is not even at the level of the sorts of patterns of neuron firings you find when the subject for example is trying to solve a certain problem. Rather, all of these things, the conscious perception or the attempt to solve a problem, only go on within a pre-existing
xviii Foreword: Addressing the Hard Problem of Consciousness conscious field. Almost all of the studies that I have seen to try to solve the problem of consciousness use subjects that are already conscious. But what we want to know is, how does the subject get to be conscious in the first place? What we want to know is, how does the brain create the unified conscious field within which the subject can then have a perception or a thought or an intentional action? It is much harder to get an account of how the brain creates the unified conscious field because our existing research techniques are not well suited to that discovery. Though progress is slow, it is no slower than other scientific problems in the past. I think we are well on the way toward having an adequate account of how the brain causes consciousness and how consciousness is realized in the brain. That would be a solution to the hard problem.