English version of the introduction to Intentionalität als Merkmal des Geistigen: Sechs Essays zur Philosophie des Geistes, translated by Markus Wild and Simone Ungerer (Frankfurt: Fischer Verlag 2007). © Tim Crane 2006 Introduction: the Mental and the Physical Tim Crane, UCL The theme of these is essays is what might be called, rather ambitiously, the nature of the human mind. Psychologists and philosophers both investigate the nature of the mind, but from rather different angles. Psychologists and neuroscientists investigate the actual mechanisms in the brain, the body and the world which underpin mental events and processes. Philosophers, by contrast, ask more abstract questions: for example, about what makes any process mental at all, or how mental reality fits into the rest of reality. Psychology and philosophy are not opposed disciplines, but complementary, and the boundary between them is not sharp. The essays collected here address some of the most abstract philosophical questions, and barely touch on actual psychological discoveries. Nonetheless, I think everything that is said in this book is consistent with what psychologists have discovered and will discover. Where psychologists will want to disagree with things said in this book, their disagreement will be based on a difference of some philosophical opinion. What, then, is a mind? What is it to have a mind? What is it for something to be mental? We can all list the various states and capacities we have which we call mental or psychological: thought, sensation, desire, emotion, perception and so on. But is there something all these states and capacities have in common, which justifies us in calling them 'mental'? I think there is, and that the concept of intentionality provides us with the answer. Intentionality is the philosopher's word for the 'aboutness' or 'directedness' of mental phenomena. A conscious thought, for example, is always a thought about something. A desire must be a desire for something, an experience must be an experience of something. Everyone who studies the mind agrees that some mental phenomena exhibit this intentionality. I go further, and follow the German philosopher Franz Brentano (1838-1917) in claiming that all mental phenomena exhibit intentionality. All mental states, events and capacities exhibit aboutness, directedness or 'of-ness'. Let us call what a mental state is about, or of, or directed on, its object. Then my central claim is that all mental states have objects, and that this is the essence of mentality. I call this claim intentionalism. Although I think intentionalism is true, I do not say it is obviously true. In Essay 1, 'Intentionality as the mark of the mental' (1998), I attempt to argue for intentionalism by arguing against those who think it is obviously false. Many philosophers think that intentionalism is false because they think that bodily sensations (for example, pains) and some emotions or moods (for example, depression) do not have objects: they are not about anything. I argue that these views rest on a misunderstanding of the concept of intentionality. When we strip the concept of intentionality of certain unnecessary associations, then we can see how the essence of intentionality can belong to sensation and emotion too. All I claim to have done in Essay 1 is to have argued that intentionalism is not easily refuted by the examples of sensation and emotion, and to have indicated in what ways an intentionalist might give an account of the intentionality of these mental states. In Essay 2, 'The Intentional Structure of Consciousness' (published in 2003 but written in 1998-9) I develop the conception of intentionality which is sketched in Essay 1, and apply it to the case of bodily sensation. It will help at this point if I give a brief sketch of how I conceive of intentionality. For me, the essence of intentionality is directedness towards an object – with 'object' interpreted in a very broad way. I include among objects material things, properties, states of affairs, facts and so on. An object is anything which one can think about, or have one's mind directed towards in some other way. Following philosophical tradition, and in particular the ground-breaking work of Edmund Husserl (1859-1938), I call these objects intentional objects. It is crucial to realise that to be an intentional object is not to be an entity or thing of a certain kind. Of course, some intentional objects are real things. If I think about Vienna, this is the object of my thought, and this is a real thing. But some intentional objects do not exist and therefore are not 'things' in any sense. If I am thinking about Eldorado, I am thinking about something which does not exist. Yet it is the object of my thought in the sense that it is what I am thinking about. Therefore, the concept of an intentional object (an object of thought) does not pick out some special class of existing or real things. To talk about an intentional object, then, is simply to talk about that on which one's mind is directed, whether or not it exists. I take it for granted that our minds can be directed on the non-existent, although this is what gives rise to the hardest problem of intentionality: how we can think about what does not exist. I do not have much to say about this problem in the essays published here, but I hope to say more about it in future work. To say that all states of mind must have an intentional object, then, is just to say that it is impossible for there to be a state of mind which is not about something, which is not directed on something. There are however different ways in which a state of mind may be directed on something: wanting to go to Vienna, disliking Vienna and merely contemplating Vienna are all intentional states, but they involve different ways of your mind's being directed at Vienna. The way in which these intentional states differ need not be in their intentional object (Vienna), but in what I call their intentional mode (wanting, disliking, contemplating). Intentional states can, however, be identical in mode and intentional object, but nonetheless differ. This is because they may differ in the way in which they present their object – or, as I put it, in the aspect under which they present it. So, for example, someone might believe that the Danube flows through Vienna without believing that the Danube flows through the city the Hungarians call 'Bécs', since they might not believe that Vienna is the city the Hungarians call 'Bécs'. The difference in these two beliefs is what I call, along with many contemporary philosophers, a difference in intentional content. The intentional content of an intentional state is just a matter of the 'aspect' under which its object is presented. Since it is impossible for an intentional state to have an object without presenting it under some aspect – or so I argue in chapter one of my book, Elements of Mind – then it follows that all intentional states have intentional content. This is supposed to be another way of expressing the simple and natural idea that it is not possible to think about something without thinking about it in some way or other. I therefore understand intentionality in terms of the following three ideas: (i) intentional object (what it is that is thought about, or desired etc.) (ii) intentional mode (belief, desire, hope, fear, perception etc.) and (iii) intentional content (the aspect under which the object is presented). How should a philosopher proceed with giving a theory of intentionality? I think the way to proceed is to examine in detail the varieties of intentional content and intentional modes. So, in Essay 2, for example, I argue that conscious bodily sensations like pains have an intentional structure. Every painful experience has as its object some part or region of the body: that is its intentional object. The object is apprehended under some aspect – for example, as one's foot – and the apprehension itself is the intentional mode, the way the object feels to you. Pain, therefore, or hurting, is a way in which parts of the body affect you. In a similar way, in Essay 3, 'The Non-Conceptual Content of Experience' I develop an account of the intentionality of visual experience. Visual experiences have intentionality, I assume, since they present objects of experience under certain aspects. But what is the nature of this intentionality? I argue that it is a form of representation which is less sophisticated than the representation involved in belief and judgement. Beliefs and judgements involve the exercise of concepts, and this goes along with their role in reasoning and inference. But experiences don't, and for this reason I agree with those philosophers who say that experiences have 'nonconceptual' contents. The basic idea is very simple: while I cannot have a belief about Vienna without having the concept of Vienna, I can have an experience of Vienna without having the concept of Vienna. The first three essays do not adopt any definite position on the relationship between mental phenomena and the rest of the natural world: what philosophers call the 'mind-body problem'. This is not because I think this problem is unimportant; it is only because I think it is not necessarily the central problem in the philosophy of mind. Many contemporary philosophers seem to be interested in the mind only in so far as it presents a problem for physicalism: the view that physics and the physical sciences tell us what there most fundamentally is, and that this is the sense in which our world is a 'purely physical' world. I differ from these philosophers in thinking not only that most of the interesting philosophical questions about the mind are independent of the truth of physicalism, but also that the question of physicalism itself is only of moderate interest. I do not deny there is a mind-body problem: in fact, I think there are lots of them. At the heart of this cluster of problems lie the problem of consciousness and the problem of mental causation. I see these two problems as forming the two horns of a dilemma. Just as the problem of consciousness seems to push us away from physicalism, the problem of mental causation pushes us towards it. Reflection on the phenomenon of conscious experience makes us wonder how experience could possibly be something merely physical, something simply in the brain. Yet when we think about how the mind must have effects in the physical world – how what we think and want makes things happen – then it seems that the mind must be something physical. Each problem reveals the inadequacy of the solution to the other. Essay 4, 'Subjective Knowledge' discusses one aspect of the problem of consciousness. Sometimes the problem of consciousness is expressed as follows: no matter how much you knew about the brain and the physical world, this would not suffice for knowing what it is like to be conscious. Therefore consciousness must be something different from anything physical. This simple argument is known as the 'knowledge argument' and has provoked an enormous amount of discussion in recent philosophy. Although I am no friend of physicalism, I do not think the knowledge argument refutes it. But it does show something interesting about our knowledge of the world: there are things that we know about consciousness which cannot be part of any scientific account of consciousness. But this does not mean that the scientific account cannot be a correct account of the reality of consciousness. If my account of the knowledge argument is correct, then this aspect of the problem of consciousness disappears. Essay 5, 'The Mental Causation Debate' deals with the problem of mental causation. This problem is essentially a conflict between the apparent fact that mental states and events have effects in the physical world and a general principle about the causal nature of the physical world, which is sometimes called the 'causal closure' or the 'causal completeness' of the physical world. This principle says that all physical effects have physical causes which are enough to bring them about. The problem then is simple: how can a mental cause have a physical effect if that effect also has a physical cause which is enough to bring it about? For example: how can a conscious desire for a drink cause your body to move to the fridge, if physical causes inside your body are already enough to bring this about? Isn't the mental cause therefore redundant? Physicalists have argued that the best solution is to identify the mental and the physical causes: there are not two causes, there is only one, which may be described as mental or as physical. This 'identity theory' is not only a good solution to the mental causation problem, but it also looks like a good argument for physicalism. In fact, it is perhaps the only positive argument for physicalism that there is. The mental causation problem arises again, however, for those physicalists reject the identity theory, as many do. For in that case, mental and physical causes are, once again, distinct. In Essay 5, I argue that the problem for these physicalists will not be solved by tinkering with the notion of causation involved. For if mental causes and physical causes bring about their effects in radically different ways, then there is no conflict between mental and physical causes, and therefore no argument for physicalism at all. Giving up the identity theory seems to leave us without any reason for being a physicalist at all. I should perhaps make it clear what my attitude to physicalism is. Physicalism, as I understand it, is not simply the view that there are no supernatural entities or immaterial souls. It is a much more controversial view than this: it says that physics and the physical sciences have the final say in the question of what exists and how things happen. So understood, physicalism is an ambitious doctrine which should not be taken as a default assumption in arguments about the nature of reality. Rather, it is in need of justification, and is important to emphasise that the justifications which have been given by philosophers are not themselves part of physics. Physics does not say that physicalism is true. I am sceptical that any of the justifications offered give us sufficient reason to believe in physicalism, and elsewhere (especially in my book Elements of Mind) I have tentatively defended what I call an 'emergentist' picture of mental phenomena. It still seems to me that the whole issue is very unclear and very unresolved. Fortunately, however, we can engage with much of the philosophy of mind without having to get involved in the debate about physicalism – as the essays collected here are supposed to show. The last essay in this book does, however, present some ideas which can form an alternative to the ideas we find in some physicalist writings. The world according to modern physics is described in terms of fields, 4-dimensional spacetime manifolds, light cones and other such unfamiliar entities. Physicalists think that this world is the whole world: the world simply is a four-dimensional entity with physical properties and relations instantiated in various points or regions within it. How, then, do the familiar objects of our everyday experience – animals, plants and the rest of what J.L. Austin once called 'medium sized dry goods' – fit into this bleak and forbidding picture? Physicalists have tried to answer this in various ways – for example, in terms of the truths about the medium sized dry goods being 'determined' by the truths about purely physical properties instantiated in spacetime. But their accounts are speculative and, so far, underspecified. Essay 6, 'Mental Substances', proposes an alternative approach. If we suspend judgement on the question of physicalism, then we also suspend judgement on whether the picture of the world given in modern physics is the picture of the whole world. What this physicalist picture lacks is any sense that ordinary physical or material objects have any real unity. Ordinary objects are just instantiations of physical properties in regions of spacetime. What explains, then, why we think of some ordinary objects as being more unified than others? An animal has more of a unity than a ball of dust. Are we wrong to think the world contains such unities? Is it simply an illusion? In 'Mental Substances' I argue that we are not wrong to think like this, and agree with those who say that we need to rehabilitate the Aristotelian notion of substance in accounting for the world we experience. In particular, I claim, in the spirit of P.F. Strawson, that persons are substances with mental and material properties. Once we have turned away from an obsession with the question of physicalism, we can begin to re-think the philosophy of mind by giving a proper place to the concept of a person as the locus of value and subjectivity in a thoroughly natural world. The essays in this book are intended as an attempt to do this.1 London, September 2006 1 I am deeply grateful to Markus Wild and Simone Ungerer for the proposal to collect these essays, for their tireless work in translating the essays and for giving excellent suggestions about the content of the volume.