The Direction of Fit of Desire Patrick Mark Butlin Ph.D. Thesis in Philosophy King’s College, London 1 Abstract It is a familiar tenet that desires and beliefs have opposite directions of fit. Our beliefs, according to this view, should be changed to fit the world – if necessary – because they are for saying how things are. Our desires give us reasons to change the world, because they are for saying what to do, or how things should be. I argue that like beliefs, desires have only the mind-to-world direction of fit. In arguing for this conclusion, I present new accounts of both desire and direction of fit. Desires are inputs to the goal-directed system – a system for behavioural control studied in psychology and neuroscience – with the function of tracking the reward values of outcomes. In the goal-directed system these states are combined with further states representing contingencies between actions and outcomes, in order to select the actions which offer greatest reward. According to this account, desires come in occurrent and standing forms, are likely to have a wide range of outcomes as their objects, and interact with habits, emotions and intentions in familiar ways. My account of direction of fit uses a teleosemantic framework. Teleosemantics is a family of theories of representation that aim to identify the characteristic functions of representations and the systems in which they operate, and focus on representation as a biological phenomenon. It is particularly suited to thinking about direction of fit, because representations have their directions of fit in virtue of what they are for – that is, their functions. I claim that representations have the mind-to- world direction of fit when the systems that produce them have the function of doing so under specific conditions, and the world-to-mind direction of fit when the systems that consume them have the function of behaving in specific ways, whenever the representations occur. Desires do not have the world-to-mind direction of fit, because what the goal-directed system should do when any given desire is occurrent also depends on what other desires are occurrent at the time, and on the agent’s beliefs. It does not follow that we have no reason to try to make the world fit our desires; instead, this conclusion shows that the place of desires in rational motivation is less closely tied to their properties as representations than some philosophers have thought. 2 Contents Acknowledgments 4 Introduction 5 Part I: Desire 1. Desire as a Natural Kind 13 2. Two Systems: Background Psychology and Neuroscience 24 3. The Neuroscience of Desire 42 4. Sources of Motivation and Action 71 5. Schroeder’s Theory of Desire 87 Part II: Direction of Fit 6. The Case for a New Theory of Direction of Fit 99 7. Teleosemantics Described and Defended 114 8. The Discretion View 141 9. The Direction of Fit of Desire 166 Part III: Motivation 10. The Humean Theory of Motivation 188 Conclusion 207 Bibliography 210 3 Acknowledgments My supervisors for this project were David Papineau and Nick Shea, and they have both made great contributions to the production of this thesis. I would like to thank them both for the long hours of work they have put into helping me to develop my ideas and refine my many drafts, and for the unfailing patience and enthusiasm with which they have done so. I would also like to thank Clayton Littlejohn, Richard Holton and Maria Alvarez, who read my work, discussed my ideas, and offered very valuable advice at various stages of the project; my examiners Stephen Laurence and Stephen Butterfill, for their careful reading and very encouraging remarks; and the staff and students of the Philosophy Department at King’s College, London for the many ways in which they have supported me. Finally, I am very glad to acknowledge the immeasurable contribution of my parents, Roger and Alison Butlin, and my wife Susannah, for their support and encouragement. 4 Introduction Our desires are among the most powerful influences on what we do and what we care about. Desires control our lives from moment to moment – at least in those moments when we have the opportunity to make choices – but they also shape our projects, careers, homes and relationships. We cannot hope to understand human motivation without understanding desire. Meanwhile, one of the central questions of philosophy is how some objects and events can represent, or be about, other things. In particular, the nature of representation is a foundational problem in philosophy of mind, since we continually appeal to the representational properties of mental states when giving everyday explanations of our behaviour and experiences, and when giving philosophical accounts of conscious experience, perception, motivation, and much else besides. This thesis aims to say what kind of representation is involved in desire. More specifically, the question I address is: what is the direction of fit of desire? My answer is that desires have only the mind-to-world direction of fit. In this introduction, I give initial characterisations of desire and direction of fit, explain why I think this is a good question, and outline my strategy for answering it. Both ‘desire’ and ‘direction of fit’ are technical terms in philosophy, although there are no widely-agreed definitions for them. Desires are mental states that interact with beliefs in motivating us to act. Paradigmatically, we are motivated to act when we believe that doing so is likely to lead to or promote the satisfaction of one or more of our desires. To fill out that idea a bit more, ‘satisfying a desire’ is taken to mean that the agent gets what they desire, not that they feel satisfaction on getting it. The objects of desire are states of affairs, often called ‘outcomes’, and desiring some outcome means wanting it to be the case. So when we are motivated by our desires, we paradigmatically believe that by acting we can make it more likely that one or more of the states of affairs that we desire will be the case. Philosophers typically think of each of us as having many desires, for a wide range of different things – more or less all of those things we would ordinarily be 5 said to want. For instance, I presently desire to drink some water, and to climb the Biancograt on Piz Bernina in the Swiss Alps, and for the civil war in Syria to end soon. Outside philosophy, it is common to attribute to people desires for things which are not states of affairs – we might say that I desire water, or that I desire the summit. But an assumption of this thesis will be that strictly speaking there are no such desires (for an argument for this view, see Sinhababu 2015). To say that I desire water is either false, or means that I desire to drink or to have some water. As well as explaining motivation and action, desires can also explain why we feel pleased or disappointed, and why some thoughts and objects capture our attention. For example, I am disposed to be pleased when I hear of success for my old rowing club, and to wonder sometimes about how they are doing, because I desire that they succeed. These points suggest that we have standing desires, which persist over long periods, because I am disposed to be pleased when I hear that my old club has won even if they are far from my thoughts at the time; but it also seems that for relatively short periods our desires can become occurrent. This would explain why I am sometimes very strongly motivated to eat chocolate ice-cream, and yet most of the time I make no effort to get it. The idea would be that my desire for chocolate ice- cream is a long-standing feature of my personality, but that it only motivates me when something about my circumstances causes it to temporarily take a different form, by becoming occurrent. Moving on to the subject of direction of fit, it is intuitive that two important categories of representation are those that aim to say how things are, and those that tell some consumer of the representation what to do. Many representations can be characterised by saying which of these two kinds they belong to, and giving the proposition or state of affairs which they say is the case or is to be brought about. Some examples will help to illustrate the point. The assertions ‘Grass is green’ and ‘Snow is white’ both aim to say how things are, but obviously differ in how they say things are. In contrast, the assertion ‘The door is shut’ and the command ‘Shut the door!’ are of different kinds, but both stand in special representational relationships to the state of affairs of the door’s being shut; the assertion says that this is the case, while the command instructs an intended hearer to make it the case. These two sentences have the same content, but different directions of fit. Direction of fit exists beyond language, however. For example, two identical scale drawings may have different directions of fit if one is intended to show what 6 an existing house looks like, while the other is a plan to be followed in building a new house. Sometimes one representation has both directions of fit; a single drawing could be at the same time an illustration of an existing house, and a specification for a new one. Why is this property of representations called ‘direction of fit’? First, note that when two things are supposed to fit one another, sometimes the ‘responsibility’ for achieving the fit lies solely or primarily with one of the two.