The Theory and Practice of Personal Identity

Transcription

1 The Theory and Practice of Personal Identity A Master Thesis by: Stijn van Gorkum (636669) Supervised by: Alfred Archer

2 Table of Contents Table of Contents 1 Abstract 2 Introduction 3 Chapter 1: The Theory of Personal Identity 5 1.1: Personal Identity and Conceptual Analysis 5 1.2: Moving Beyond Conceptual Analysis : Ethics Over Metaphysics : Conclusion 17 Chapter 2: The Practice of Personal Identity : What Matters in Personal Identity Is Psychology : Objection 1: The Pluralism of the Practical : Objection 2: Strawson's Episodic Ethics : Conclusion 41 Conclusion 42 Bibliography 44 1

3 Abstract 1 In this thesis, I will discuss both the theory and practice of personal identity. In the first chapter, I will focus on the theory: what the discussion is about, and what it should be about. I will argue that there isn't one general discussion, and one corresponding metaphysical theory of who we really are, that can address all of the identity-related questions that interest us. Different theories of personal identity are often not competing for the same answer but are best seen as trying to answer different kinds of questions that are associated with different aspects of sameness, and understanding that will better enable us to appreciate the insights that different theories have to offer. That does not mean, however, that there are no important identity-related disagreements, and in the second chapter, I will discuss practical disagreements about when a person should be considered and treated as the same person for certain practical reasons (e.g., moral responsibility or prudential concern). I will argue that, for most of our identity-related concerns, we should (mainly) look to psychological connections, to people's minds, as opposed to biological relations, to animals. In addition, most of them are made possible by the existence of persons, who are defined by their psychologies. But we will see that some of our concerns are (also) associated with other aspects of sameness changes to our bodies, for example, or with biological continuity. This means there isn't one general identity relation, one universally applicable theory of which aspects of sameness are the ones that matter, that can address all of our identity-related concerns and practices. Finally, I will argue that there isn't one right way to experience our lives: different individuals can permissibly relate to their past and future in different kinds of ways, within certain limits. The general theme of my thesis is that personal identity is messier, more complicated and more plural than we might have thought, but that there are are also patterns lying underneath, especially once we become more specific. 1 Many thanks to Alfred Archer for his helpful comments on earlier drafts of this thesis! 2

4 Introduction One man walks up to another man. Hey!, he says, when can I expect the money back that you owe me? The other man, a philosopher, remains silent for a moment before he finally responds. Imagine a heap of sand, he says. And imagine that most of the particles of sand it was composed of have been displaced after a heavy storm. A small heap still remains, and some time later, a heap of sand very similar to the first re-emerges on top of the old one. Wouldn't you agree that this heap of sand is a different heap than the first one? The first man answers, somewhat irritated: I suppose it is a different heap, yes. What's your point? The philosopher's eyes start to glow, as if victory is now within his grasp. Well, in exactly the same way, the person you loaned money to has changed greatly since then: most of his cells have been replenished, beliefs have been gained, memories have been lost and new desires have been acquired. So if you agree that a heap of sand is no longer the same after it has endured great changes, surely you should agree that I am not the same person as the person you loaned money to? And if that is true, it clearly would be a great injustice to hold me responsible for his debt! The first man raises his eyebrow and proceeds to smack the other man on his ear. What did you do that for?!, he complains. The man smiles. Who? Me? In my view, this story 2 illustrates the problem of personal identity quite well. Clearly, people do change all the time: the matter of which we are composed our cells, the bacteria that support or attack them, etc. is continuously replaced, until little is left; our bodies change enormously, and looking back on pictures from our childhood, it can be difficult to believe that it really is your body that is shown on the pictures; and our minds have evolved so much since our childhood that we now have more in common in terms of our values, beliefs, desires, intentions and character traits with most of our peers than with the child it is said we once were. And this means there is a clear sense in which I am not the same person as the child who shared my name, or even my name-carrier of a week ago: not everything that is true of him is true of me, and vice versa. In this absolute sense of identity, I am only identical to myself at a time, but not over time: any change destroys it. As my little story illustrates, however, this kind of identity doesn't interest us very much. Yes, we change, but we don't think this change destroys every sense of identity that matters, that there are no important senses in which we can survive changes to our bodies and minds. Some changes kill us, without question: if our bodies die and our minds disappear, so do we. But other changes do not make an individual vanish: they are precisely changes of an individual, changes that she undergoes while retaining the aspects of sameness that are fundamental to who she is. And it is this sense of identity that the problem of personal identity is concerned with. The existence of change is only a starting point: what interests us is which changes a person can survive without perishing. 2 I didn't come up with this story myself. I think it was a joke from ancient Greece, but I could be wrong about that. 3

5 In this master thesis, I will approach this topic from two directions. In the first chapter, I will focus on the theory of personal identity. What is the discussion about? Are all participants interested in the same kinds of questions, or are they, to a certain extent, talking past each other? And is there really one general answer to the question who we are, and how we persist over time? My argument will be that there isn't: there is no one general metaphysical theory of who we are that can answer all of the identity-related questions that interest us, so trying to find one will lead us nowhere. We are not either animals or psychological beings: we are both! Theories that claim that we go where our biology goes and theories that claim that our psychology captures who we are do not, in my view, compete for the same answer, but are really trying to answer different questions, and both offer perfectly legitimate answers to those questions. And once we see that, the conflict disappears. That does not mean, however, that there are no important identity-related disagreements, and in the second chapter, I will focus on one of them: disagreements regarding when a person should be treated as the same person for certain practical reasons. For example, when should one person be held responsible for certain actions that were performed in the past? How should we feel about our past? What kinds of changes retain what matters in survival? Which future person should we have special concern for, and how much? And when is it reasonable to anticipate certain experiences? And here, too, things will turn out to be more complicated than we might have hoped. What matters most for the above kinds of concerns is that our minds survive, that there are psychological relations between one individual and another, and our psychologies are what make many of these concerns possible in the first place, but we will see that some of our concerns also focus on other aspects of sameness changes to our bodies, for example, or whether the animal survives. And we will also learn that different people experience their lives in different ways: some people strongly identify with their (further) past or future, despite the low amount of connections between now and then, and may even actively try to find thematic unity in (large segments of) their lives, while others don't, and it isn't clear that either of these lives is superior to, better or more meaningful than the other. In general, I will argue that the personal identity discussion is more plural than we might have thought: instead of there being one general discussion that can address all of the reasons why we're interested in persistence relations, there are several more specific disputes that are associated with different aspects of sameness; instead of there being one general identity relation that can address all of our identity-related concerns and practices, different types of concerns are associated with different types of relations, although psychological relations do have a special place; and instead of there being one right way to experience our lives, different individuals can permissibly relate to their past and future in different kinds of ways, within certain limits. This may not be what we hoped for, but given the messiness of reality, perhaps we should have seen it coming. 4

6 Chapter 1: The Theory of Personal Identity As I mentioned in the introduction, this chapter will focus on the theory of personal identity, thus laying the methodological groundwork for the rest of my thesis. It will consist of four sections. In the first section, I will explain how personal identity theorists regularly proceed by means of conceptual analysis and argue that this method cannot resolve the discussion, because our semantic practices are semantically indeterminate between the different candidates. There is no universally applicable metaphysical theory of who we are that can address all of the reasons why we're interested in people's identity conditions, and different theories are often best seen not as competing for the same answer, but as trying to answer different kinds of questions. In the second section, I will argue that there are nevertheless important practical and metaphysical disagreements, and consider where progress might lie. I will suggest that if we're explicit about what question it is we're investigating, real progress might well be within our grasp. In the third section, I will argue in favor of one interpretation of practical disagreements about personal identity: that they cannot be resolved by a metaphysical theory of personal identity. Instead, we should proceed the other way around (in other words, we should prioritize ethics over metaphysics): start out with considering which relations are important for practical purposes, and then integrate them in an account of personal identity, an account that will, therefore, be essentially practical. I will also argue that personal identity does not provide us with an independent justification of our practical attitudes. Rather, the reason we care about personal identity is that it tracks certain relations that are important for other reasons. Finally, in the conclusion, I will summarize what I've argued for and explain how it ties to what comes next. 1.1 Personal Identity and Conceptual Analysis In this section, I will explain why I believe that the method of conceptual analysis, a method that is quite popular among personal identity theorists, is incapable of resolving the discussion in the controversial cases where it's most needed. But before discussing what this method consists in, and what its weaknesses are, let me first explain what exactly is at issue in this debate. To begin with, the question of personal identity is a diachronic, not a synchronic question. In other words, the discussion is not (centrally) about what I am now (though an answer to that question may be presupposed). Rather, it is about what it takes for me to persist over time, about which beings from the past and future are identical to me. For instance, if I suddenly lose all my memories, will I still be there? Or will I have disappeared? Or suppose that all my psychological states are transferred to a new body. Will that new body be me, or will I have died with my old one? More interestingly, framing the debate as a discussion about personal identity is actually rather misleading, because it suggests that the concept of personhood is essential to the discussion. 5

7 In other words, it suggests that what is being discussed is what it takes for a person to persist over time, or: If a person x exists at one time and a person y exists at another time, under what possible circumstances is it the case that x is y? (Olson 2016, 2). Some personal identity theorists certainly are mainly interested in this question, but that is because they accept what Olson calls person essentialism : they believe that we are essentially persons, and therefore share their persistence conditions. But this is a controversial claim, so its truth should not be assumed at the outset. What is being discussed as I take it, anyway is a somewhat broader question: what it takes for someone, a particular individual who may or may not be a person, to persist over time. In other words: if a certain individual x exists at one time and something y exists at another time, under what possible circumstances is it the case that x is y? This leaves open the possibility that I was once an embryo, or will one day end up in a persistent vegetative state. In short, what is being discussed is what the persistence conditions are of you and me, what it takes for us to persist. In contemporary analytic philosophy, two families of theories are prominent. The first family consists of psychological continuity theories. 3 According to these theories, what determines whether an individual persists over time are psychological relations. A person A is identical to a person B because he has inherited (or because B will inherit) his psychological states and dispositions, or is at least linked to B through a continuous chain of psychological connections of this sort. What matters is, in other words, that their psychologies are linked. How exactly they are linked, and whether further requirements are needed in addition to psychological continuity (e.g., a requirement that the psychological relation in question applies to no more than one individual, or a requirement that the relation is underpinned by a continuous physical relation), is a matter of controversy. The second family consists of physical (or biological) continuity theories. 4 According to these theories, what determines whether an individual persists over time are physical (usually biological) relations. A person A is identical to a person B because they are linked through a continuous chain of physical relations. For instance, according to one prominent theory, what determines whether one individual is the same individual as another is that they have the same body; according to another, what matters is that they are the same biological organism, the same human animal. What matters in these theories, in short, are physical (biological) links, not psychological connections. The dominant method personal identity theorists have used in order to attempt to answer the persistence question is arguably to think of cases where different theories give different answers, and then to consider which of these answers is intuitively more plausible. The correct theory is 3 A psychological theory of personal identity was famously developed by Locke (1690), and variations of his view retaining his key insight that psychological connections hold the key to our persistence over time are still very popular. Two highly influential contemporary proponents are Derek Parfit (1984) and Sydney Shoemaker (2011). 4 Physical theories have become popular relatively recently, as a reaction against the dominance of psychological theories in analytic philosophy. Their most influential proponents are Williams (1957, 1970) and Olson (1997). 6

8 supposed to be the one that best predicts and explains our considered judgments about who is who across a range of these cases (West 2010, 88). In other words, in order to test the available theories, philosophers construct thought experiments where the different theories diverge, and the best theory is supposed to be the one that fits best with our intuitive judgments about who is who in these cases. To give you an example, suppose that all of A's psychological states are somehow transferred to B's body, and suppose that B's psychological states are transferred to A's. B now has the beliefs, values, memories and personality of A, and vice versa. How can we best describe what happened here? Is the best description that A has switched bodies with B, or is the best description that A and B have switched their psychologies, but remain the same individual? Or suppose that A has irreversibly fallen into a persistent vegetative state: he has no consciousness, and is incapable of ever regaining it. Does A no longer exist, or does he still exist in a vegetative state? In my view, this approach is quite reasonable. Our reactions to cases where different theories diverge can certainly help us to assess their plausibility. If a theory does not fit our intuitions about these kinds of cases, that plausibly counts against it. Some theories may even be ruled out. But I also believe this method has clear limitations. Unfortunately, people's intuitive responses tend to vary considerably, even after having reflected extensively on all of the cases. And, as West (2010, 88) writes, after more than a century of pumping intuitions regarding many and varied such puzzle cases, we still seem no closer to reaching a consensus in favour of any one of the theories that have been proposed. The personal identity debate seems to have reached an impasse. And the above method seems incapable of getting us out of that impasse: in order to make progress, we need to ask ourselves other questions. Fortunately, I'm not the first person to have made this suggestion, and in order to further develop my views, it will be instructive to briefly discuss the arguments of three of these philosophers: Ted Sider (2001), Caroline West (2010) and Hannah Tierney et al. (2014). The general core of their arguments is highly similar. They start with the assertion that there are multiple candidate meanings for the concept of personal identity, and for the sake of clarity, they (mostly) limit their discussion to psychological and bodily theories. Then, they argue that neither of these theories fits our use of the concept of personal identity our semantic practices regarding that concept better than the other. They usually coincide, but when they come apart (in extraordinary actual circumstances, like persistent vegetative states, dementia or radical psychological transformations, or in counterfactual circumstances, like the body switching case), our reactions are equivocal and inconstant. It seems we are capable of having intuitions that fit with both theories, and this seems to indicate that neither candidate fits use much better than the other. This also explains why the disagreement over which theory of personal identity is so persistent: people who agree about the non-personal facts of cases, who are informed and linguistically competent and have thought exten- 7

9 sively about a wide range of cases continue to disagree about whether persons persist in these cases. The reason why this disagreement is so persistent is that it cannot be resolved, because there simply is no best deserver that best fits our commonsense beliefs about personal identity, as West (2010) puts it, no one theory that clearly stands out from the others, that best captures the meaning of the concept. And from this argument, each of them draws the same conclusion: because our practices are semantically indeterminate between the different conceptions, there simply is no fact of the matter whether the persistence of persons is governed by psychological or bodily continuity (Sider 2001, 200): we have not one but at least two concepts of persisting persons, each responsible for a separate set of intuitions, neither of which is our canonical conception to the exclusion of the other (197). In other words, the method of conceptual analysis leads to pluralism, and the reason the debate has reached an impasse is that it is trying to find unity where there is diversity. 5 I fully agree with this core argument, but some disagreements arise when the authors diverge from, add other elements to, this main claim. Let's start with Ted Sider (2001). I actually simplified his argument somewhat, because he argues that the meaning of a concept is determined not just by how it is used, but also by how eligible it is, where eligibility consists in naturalness : a candidate is more eligible than another if it better carves nature at the joints, has a more natural basis in the perfectly natural properties and relations (199). Sider believes none of the candidates does better in this respect either, because hundreds of years of discussions of puzzle cases have not significantly changed how the criteria are understood. If one of the candidates had a better basis in nature, we would have known by now. In my view, however, Sider is wrong here, in two respects. First, measured by the criterion of naturalness, biological criteria actually do much better. Psychological relations are much less precise than biological relations, much less well-defined: they are a matter of degree (e.g., an individual with Alzheimer's may be psychologically related in some ways to her past self e.g., similar character traits but not others e.g., because she has lost most of her memories) and can hold over vast distances of space and time (e.g., if information about the psychological relations in my brain is transmitted to another planet and is used to forge a new body that has all my memories, beliefs etc. after my body on Earth has been destroyed). Biological relations, on the other hand, are more absolute (an animal is either alive or it isn't, though where to 5 Another author that is worth mentioning is Galen Strawson (2009). He also endorses a pluralism of sorts, though his comments on the topic are very brief: I reject the assumption that the word 'I' is univocal the assumption that it has only one possible meaning or reference in thought or speech. The reference of 'I' both its actual reference and its explicitly or implicitly intended or presupposed reference standardly shifts between two different things in my thought and speech and in the thought and speech of others. Sometimes 'I' is used to refer to a human being considered as a whole, sometimes it is used to refer to a self. ( ) Parfit (2012) similarly argues that pronouns are ambiguous: sometimes we use them to refer to a person, sometimes to an animal. But Parfit does think there is a fact of the matter as to which of these two we really are. However, in making this argument, Parfit uses nonsemantic premises, basically arguing that the person is the more important entity (see note 11). 8

10 draw the line is, of course, a tricky affair) and continuous and contiguous in space-time (i.e., from one moment to another, the persistence of an animal is maintained by causal links that hold over short distances in space and time). If, then, our aim is to find a candidate that has a better basis in natural relations, that has a natural unity with clear identity conditions, we should adopt a biological account or at the very least, psychological relations should be combined with biological relations in a mixed account (e.g., it can be argued that psychological relations must have a continuous biological foundation in part of the brain; see Parfit 2012 for this argument). But, second, I don't think our semantic practices do definitively favor seeing ourselves as natural kinds: if our talk of persisting individuals is semantically indeterminate between defining ourselves as animals and representing ourselves as psychological beings as Sider argues and the identity conditions of the latter are not those of a natural kind, then our practices do not imply that we are necessarily natural kinds. Instead of being natural, the unity that captures who we are could be a functional unity whose persistence conditions are more comparable to those of companies and ships than to those of plants and animals, in the sense that they are determined by our interests in the relevant entities, by what aspects of its persistence we care about, what aspects matter to us. For example, imagine that my body is dying and my psychology is transferred to a mechanical body. In such a case, our practices clearly allow saying that I have survived the death of my old body (a lot of science fiction wouldn't make much sense to us if it didn't) because what matters most to me as a person is still there, but this survival is not the survival of a natural kind. But if our practices do not definitively favor seeing ourselves as natural kinds over seeing ourselves as non-natural kinds, then Sider's eligibility criterion is not necessary for his conclusion: his criterion of use is sufficient. Next, let's discuss West (2010). I have simplified her argument as well, because she actually believes that we do have a candidate theory that best captures our person-related beliefs: the view that we are essentially immaterial souls. On her view, it is the idea that we are a featureless 'soul pellet' (93) that best explains our central beliefs about the persistence of persons. However, she also believes that souls do not exist, so we cannot be persons in that sense. Given the centrality of personal identity in our lives, eliminativism believing that we do not persist over time is not, she argues, an option. We should therefore accept revisionism: that is, we should see if a similar conception is available that does exist and fits well enough with our beliefs about personal identity to be deserving of the label. Fortunately, these are available in the form of psychological and bodily theories and it is to these two theories that her argument in favor of pluralism applies. 6 6 For a very similar argument, see Robinson (2004). She also believes it is necessary to revise some of our beliefs about our persistence in the absence of souls, and that diverse person-concepts may be legitimate, no non-questionbegging standards declaring any of them unfaithful to facts or established usage, or plainly irrational (512). And she also argues that there is real disagreement, and that progress lies in non-semantic (especially, ethical) methods. 9

11 I agree that certain of our commonsense beliefs about personal identity the idea that our identity conditions are simple and absolute, that there is one true me, for instance, or that reincarnation is a coherent idea seem to require souls. But as Locke (1690) argued centuries ago, other beliefs don't fit well with the idea that we are souls at all. For instance, suppose I have the same soul as Socrates. Does that mean I am Socrates, despite not sharing his body and psychology? Does it mean I own his stuff and am responsible for his deeds? Of course not. Indeed, you might argue that the main reason why it's compelling to think we're souls is that they are associated with our mental features. Take that away, and all that remains is indeed a featureless soul pellet. And it seems rather implausible to identify ourselves with something that has none of our identifying features. In my view, her point can be stated more simply: some of our beliefs about our persistence over time may indeed require the existence of souls, and therefore need to be revised in their absence. But many of them don't, so it is an exaggeration to claim that souls best explain our persistence beliefs. West also explicitly focuses on the identity conditions of persons, not individuals in the broader sense. She connects personal identity to ethical considerations like self-concern and moral responsibility, and by doing so, she connects personal identity to personhood. But some participants in the discussion have claimed that personal identity, as they understand it, has nothing to do with ethical considerations: our persistence over time is, on their view, a metaphysical, not an ethical relation, so it doesn't count against their view that their account doesn't track practical relations. It seems that this is another point where semantic considerations are equivocal. It is perfectly coherent to argue that certain practical relations are essential to who we are, but so is arguing the opposite. Finally, while Sider and West reason from the armchair, Tierney et al. (2014) support their argument with empirical evidence. Their main inspiration is a thought experiment by Bernard Williams (1970). This thought experiment has two variations. In one version, readers are asked to imagine two persons, A and B, who are abducted by a mad surgeon. He tells A and B that he will transfer A's psychological states his memories, values, character traits and so on to B's body, and vice versa, and warns them that he will torture either A's body or B's body. He then gives A a choice: he can choose which of them will be tortured after their psychologies are swapped. It seems that, judged by his self-interest, A should choose that A's body will be tortured: what matters for personal identity here, it seems, are psychological characteristics, not biological features. But now imagine a second variation. In this version, there's only A, and he is told the following. Your body will be tortured, but before doing so, I will remove all of your psychological features and replace them with new ones. If what matters for personal identity are psychological characteristics, he should not feel fear or anticipate being tortured, but these attitudes do seem reasonable. It seems, then, that the attitudes we have towards future individuals do not track one fixed criterion. 10

12 In several experiments, these intuitions have been put to the test. Nichols & Bruno (2010) probed people's reactions to two Williams-type cases and found that non-philosophers tend to have the same judgments as philosophers: in the first kind of case, they judge that people go where their psychology goes; in the second kind of case, they judge that people should fear pain despite losing their psychological characteristics. Tierney et al. ( 1.1) extend this work. Their experiments indicate that inducing people to believe that psychological relations to their future self will be weak or strong influences economic decisions (to what extent the interests of a future self are discounted: more in the low connectedness case) and punishment judgments (how much punishment they deserve: less in the low connectedness case), but not anxiety about future pain. These experiments suggest that pluralism isn't limited to philosophers: the judgments about personal identity of nonphilosophers cannot be captured by one universally applicable identity criterion either. So, what are we to make of all this? We have seen that, if participants in the personal identity discussion solely rely on the method of conceptual analysis, the result is an impasse: despite being informed participants who have extensively reflected on a large variety of cases and agree on the non-personal facts, disagreement remains persistent. And the authors I've discussed have a straightforward explanation for this: disagreement is so persistent because it is irresolvable, at least by the method of conceptual analysis. Neither the psychological nor the biological view is wrong: both are consistent with our semantic practices. The only thing that proponents of these views are doing wrong is to suppose that they are uniquely right and the others wrong, while in reality both are (partly) right. We have also seen that we cannot presuppose that personal identity is a natural kind, or that it is essentially associated with certain practical relations. Both of these presuppositions are linked to investigations that are perfectly legitimate: looking at personal identity as a natural kind, and looking at it as something essentially practical. But if that's what you're investigating, you should be explicit about it, and not simply assume that the presupposition is essential to the debate. Finally, we have seen that the fault doesn't simply lie with confused philosophers. Pluralism is also found among non-philosophers: like philosophers, their reactions can be made to track different criteria depending on which of our concerns are highlighted. When the criteria coincide, as they do in ordinary cases, there is no problem; but when they diverge, indeterminacy is inevitable. 7 In such cases, it seems, all we can say is that the individual is the same in one sense, but not in another. 8 As 7 This point is reminiscent of a quote by Quine (1972): The method of science fiction has its uses in philosophy, but at points in the Shoemaker-Wiggins exchange and elsewhere I wonder whether the limits of the method are properly heeded. To seek what is 'logically required' for sameness of person under unprecedented circumstances is to suggest that words have some logical force beyond what our past needs have invested them with. (490) 8 Cf. Parfit (1984): on the Reductionist View [i.e., the view that personal identity is not a further fact on top of the non-personal facts but can be reduced to those facts], the so-called 'problem cases' cease to raise problems about what happens. Even when we have no answer to a question about personal identity, we can know everything about what happens. (266) Parfit does think some of the problem cases have a best description, however: though it may 11

13 Baggini (2011) puts it, [a]s long as you know what aspect of sameness matters to the questioner, you can provide an answer (132) that provides him with the information he's looking for, but you can't give one uniquely correct answer to the general question whether one individual is really the same as another that is valid regardless of context and addresses all of our identity-related interests. None of this means that there aren't important identity-related disagreements, however, as most of the authors I've mentioned explicitly acknowledge, and as I will argue in the next section, these can be addressed by asking other, more specific questions than the one I've focused on here. 1.2 Moving Beyond Conceptual Analysis As we have seen, West (2010) believes that conceptual analysis cannot resolve the question whether we're animals or psychological beings: both views are consistent with our practices. But like me, she doesn't believe that means we're left with uninformative answers to all of our identity-related questions. However, in order to discuss them, we should move to other methods. In her view, there are at least three ways in which we can move beyond conceptual analysis, and thereby make progress in the discussion by uncovering important disagreements that are potentially resolvable. First, she argues that there are important ontological disagreements. As an example, she discusses the well-known debate among three-dimensionalism and four-dimensionalism. Threedimensionalism maintains that the relation of personal identity, whatever its details, is an identity relation between two three-dimensional objects: one person is the same person as another if she is the same three-dimensional object. Four-dimensionalism, on the other hand, maintains that a person is a four-dimensional object, extended not just in space but also in time: what makes one person identical to another is not that they are the same three-dimensional object, but that they are stages of one four-dimensional object. However this discussion is resolved, the disagreement between the participants is genuine and potentially resolvable. And, though I don't expect that which of these theories is correct will decide between psychological and biological theories (because those theories are consistent with both metaphysical frameworks), it might have implications for the various more specific theories whether they're consistent with the facts, and how they should be formulated. Second, one of the candidates might better carve nature at its joints might be more eligible, as Sider (2001) puts it. One aim of several participants in the debate is plausibly to find a natural kind with clear identity conditions that individuals can be identified with in one important sense of the word. As I argued in the last section, biological accounts or at least theories of which biological relations are an essential part do much better on this count, because biological relations not describe a different metaphysical possibility than another description, it is better because it fits better with our semantic practices, or because it better captures what matters, better singles out what is important to us. 12

14 are more clear-cut than psychological relations, less a matter of degree and forming a natural unity in space and time. But the questions don't stop there, because once we've become explicit about our focus on natural kinds and have identified which natural kind we're concerned with, some tricky matters still remain to be resolved. For example, when, exactly, does the life of an animal begin and end? 9 And how should biological relations be understood? What does biological persistence consist in? Answering these kinds of questions is essential to making progress on this front. Finally, we can ask ourselves which of the candidates is best suited to being the object of our identity-directed ethical practices: that is, what relation(s) among different person-stages should structure our practical concerns regarding persons (West 2008, 56) concerns like whether (and to what extent) an individual should have prudential concern for a future individual, whether (and to what extent) he should be held morally responsible for an action that was performed in the past, how (strongly) he should feel about that action, and so on. It is of the utmost importance in our ethical lives how we should relate to individuals from the past and future, and one important aim of an account of personal identity is plausibly to tell us what we should do in that regard, to tell us which persistence relation(s) our practical concerns with regard to personal identity should trace. 10 Once again, disagreements about this matter are genuine, and even if they turn out to be irresolvable (i.e., if moral anti-realism is true), discussing them is surely an important task for philosophers. 11 Traditionally, many have assumed that these two kinds of questions the metaphysical question about personal identity as a natural kind and the practical or ethical question about personal identity as something we should structure ethical concerns and practices around should have the same answer: a metaphysical theory of personal identity with practical consequences. As West (2008) writes, [i]t is natural to think that the metaphysical question and the practical question are intimately connected: the relation that should structure [our practical concerns] is that of being 9 Actually, the end result of discussing this question may very well be that there is no exact point where an animal's life can best be said to begin or end, that deciding where to draw the line is, to some degree, arbitrary. It may also turn out that the decision where to draw the line is, at least in part, an ethical choice, determined by the reason why we're interested in drawing it. But if these are really facts, becoming aware of them would also be progress. 10 Note that this way of putting things is somewhat ambiguous. On the one hand, there is the question which account of personal identity captures our current practices; on the other hand, there is the question which account our practices should be structured around. Both are legitimate questions, but I am mainly concerned with the second question. 11 Similar distinctions have been drawn by many other philosophers. For example, both Shoemaker (2007, 317) and Bělohrad (2014, 315) distinguish between two sets of philosophers with different motivations: the first group is mainly interested in the metaphysics of the identity relation and seeks to develop a theory of personal identity to cohere with the broader picture of the identity and persistence of spatiotemporal objects (Bělohrad 2014, 315); the second group is mainly interested in the relation between personal identity and our ethical practices and concerns and attempts to develop a theory of personal identity to justify some of the practical concerns and attitudes that have traditionally been taken to presuppose the concept of personal identity (ibid.). Baggini (2011) similarly distinguishes between a logical question about the identity of objects and the existential question of how I should think about and relate to past and future versions of me (134). And of course, Locke (2011) famously distinguishes between animal identity and personal identity, and he considered the latter an essentially forensic concept that grounds our person-related practical concerns, like self-concern and moral accountability. 13

15 one and the same person over time (57). But if the metaphysical question is defined in terms of the project of looking for a natural kind, it is not at all clear that it will deliver the same result as the practical question. Indeed, West (2008) argues that answering the practical question requires seeing personal identity as a non-natural social kind whose persistence conditions are partly determined by the practices of individuals and communities (58). And Olsen (1997) claims that same person has two distinct senses, a practical sense and a metaphysical sense, and then goes on to argue that there is no reason to think that these two senses coincide in one entity: rather, they are associated with distinct questions, and answering the one question is irrelevant for answering the other. This brings me to the general point of this section: that progress in the personal identity debate lies, most of all, in being explicit about what, exactly, it is you're asking. All of the questions I have distinguished seem perfectly legitimate to me, but it is essential to recognize that, despite their similarities, the questions are indeed distinct, so you cannot assume without argument that they will have the same answer. If you're looking for a natural kind, or trying to find out which relation we should structure our identity-related practices around, or trying to answer a combination of these questions (e.g., what natural kind, if any, (normally) underlies practical identity?), clearly state that this is what you're doing. Be specific and explicit about what you're asking, because debating personal identity without clearly defining the term inevitably results in a stalemate. 12 To quote Baggini (2011) again, [a]s long as you know what aspect of sameness matters to the questioner, you can provide an answer (132); but in the absence of that information, progress cannot be made. 1.3 Ethics Over Metaphysics In the last section, I argued that one way of making progress in the personal identity debate is to examine which persistence relation(s) our identity-related practices should be organized around, to discuss which of the different candidates psychological theories, physical theories or some other relation those practices should track. But this project can be understood in two different ways. On one view, metaphysics has priority over ethics: as Shoemaker (2007) puts it, we should first come up with the correct metaphysical criterion of personal identity, and then see what it implies for our practices (319). 13 This view has two components: a methodological and a normative component. The methodological component holds that, as one of its proponents, Henderson (2013, 48) writes, ontological questions of personhood and persistence are methodologically prior 12 One example of a philosopher who is, in my view, not as clear as he could be is Parfit (2012). Early in his paper, he claims that psychological theories need not fall back on the claim that personal identity is essentially a practical term: they can rely on thought experiments instead. But then, later in his paper, he argues that we are our cerebrum instead of human animals because they are the most important parts of these animals, the parts that do all the things that are most distinctive of these human animals, as conscious, thinking, rational beings (25). Clearly, which part of the animal is most important is a practical claim about what matters to us. He should be more explicit about this. 13 Shoemaker believes this methodology is too simplistic, however. He just summarizes it very well. 14

16 to the ethical questions. Without answers to the ontological questions, there cannot be answers to the ethical questions. The normative component claims that the reason why ontological questions have priority is that a metaphysical theory of personal identity justifies our person-related concerns. On another view, favored by West (2010), ethics 14 has priority over metaphysics: Ethical considerations become the arbiter of the question of personal identity, rather than the other way around (103). Ethical questions are methodologically prior to ontological questions because the reason why we are interested in certain persistence relations is that they have ethical importance, that they are of interest to us, rather than the other way around. It isn't the metaphysics of personal identity that justifies the ethics of personal identity: rather, it is the practical importance of certain persistence relations that justifies using a concept of personal identity that tracks those relations. I endorse the second view, in both of the senses that I have identified. First, I accept its claims about methodology: in order to answer our practical question, we cannot rely on mere metaphysics but must make essential reference to ethics. It might be thought that this trivially follows from what I've been arguing in the first section of this chapter: if there isn't one general metaphysical theory of who we are, then metaphysics cannot settle who we are for practical purposes and we must fall back on other methods. But this is too quick: even if there is no general metaphysical theory of who we are, our practical question might still be settled by a more specific metaphysical theory a theory of who we are qua persons, in the more narrow sense of the word that is essentially connected with personhood. However, it is not at all clear that persons in this sense can be defined in a way that does not make essential reference to ethical considerations: a person in this sense is plausibly a nonnatural kind whose identity conditions are a function of what matters to us about their persistence. In other words, because (narrow) personal identity is ethical in nature, we need ethics to identify it. For example, when considering whether someone is the same person after a brain transplant, we seem to be asking ourselves whether she still has what matters in identity a practical question. 15 But let us suppose, for the sake of the argument, that the identity conditions of persons, what they are and how they persist over time, can somehow be identified without falling back on ethics. In that case, it becomes unclear why we should organize our identity-related practices and concerns around persons instead of some other being. Why, after all, should a purely conceptual or metaphysical approach be able to answer ethical questions? Doesn't this run up against the gap between is and ought? How can a theory about what persons are imply that our identity-related concerns ought to follow their lead, without already presupposing that we are interested in persons for ethical 14 I use ethics in the broad sense of the word, as covering all of our normative concerns about how we should live our lives, not in the narrow sense of morality. 15 Again, this is nicely illustrated by Parfit (2012), who seems to illicitly smuggle in ethical considerations in order to argue in favor of his theory of who we are while claiming to stick to uncontaminated conceptual analysis. 15

17 reasons? At the very least, an explanation is needed of how a supposedly metaphysical methodology can have normative implications. And this explanation should do more than to state that it is an independent truth of morality or rationality that it is appropriate to regard and treat earlier and later stages as the same person only if they are the same person in the metaphysical sense, as West (2008, 65) puts it: it needs to explain why this is true, and how it can be so. Neither of these two objections are knock-down arguments that definitively refute prioritizing metaphysics over ethics: maybe it can be done somehow, and maybe an explanation of how it can be done can really be provided. But I do think the difficulties of that methodology are at least considerable enough to try to look for an alternative and the success of that approach might in turn enhance its credentials. The ethics over metaphysics -view can also be understood in a second way, however, as a view about what it is that justifies our person-related practices. Even if personal identity is ethical in nature, it might still have irreducible normative importance. In other words, it might be the case that our person-related practices and concerns are directly justified by the relation of personal identity in virtue of its ethical significance. In my view, this is false: the relation of personal identity indeed has practical importance, but its significance is derivative from lower-order practices and concerns. Personal identity isn't intrinsically significant, isn't important because it justifies our person-related practices and concerns: it is significant because it traces practices and concerns that have independent value. As Susan Wolf (1986) succinctly puts it, the answer to, Why care about persons is that life, or, if one prefers, the world, is better that way (713). I agree. The justification for our person-related practices and concerns is that the world is a better place, and our lives are richer and more fulfilling, because of having them. In other words, though Wolf might not follow me here, the justification for structuring our practices around a certain candidate is strictly consequentialist: they should be organized around that relation because doing so promotes the good, because it improves all of our lives. That relation doesn't have intrinsic but only instrumental or derivative normative significance. For example, the reason why we should hold people responsible for certain actions from the past is not that it is a metaphysical truth that they performed them, but that holding individuals responsible for actions they relate to in a certain way promotes the good, promotes responsible behavior. And the reason why we should consider certain changes as survival is that those changes preserve what is valuable in the life of a person, preserve what matters in survival. In the remainder of this thesis, however, only the methodological interpretation of the ethics over metaphysics -view will be necessary, i.e., the idea that which relation(s) our practices should be organized around should be evaluated by how well it captures our practical concerns with respect to personal identity. Whether that relation has independent justifying force or derivative significance at most is not essential to my argument. However, my endorsement of the latter claim might still be 16