Philosophy Week 16
Popular in Department
This 26 page Class Notes was uploaded by Bharat Punna on Saturday December 5, 2015. The Class Notes belongs to at Auburn University taught by in Summer 2015. Since its upload, it has received 25 views.
Reviews for Philosophy Week 16
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 12/05/15
Philosophical Review Personal Identity Author(s): Derek Parfit Reviewed work(s): Source: The Philosophical Review, Vol. 80, No. 1 (Jan., 1971), pp. 3-27 Published by: Duke University Press on behalf of Philosophical Review Stable URL: http://www.jstor.org/stable/2184309 . Accessed: 07/12/2011 13:56 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, availa.le at http://www.jstor.org/page/info/about/policies/terms.jsp JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact firstname.lastname@example.org. Duke University Press and Philosophical Review are collaborating with JSTOR to digitize, preserve and extend access to The Philosophical Review. http://www.jstor.org PERSONAL IDENTITY, W E CAN, think,describecases in which,thoughweknow the answer to every otherquestion,we have no idea how to answer a question about personal identity.These cases are not covered by the criteriaof personalidentity that we actually use. Do they present problem? Itmightbe thought thatthey do not, becausethey could never occur. I suspect that some of them could. (Some, for instance, might become scientificallypossible.)t shall claim that even if they did they would present no problem. My targets are two beliefs: one about the nature of personal identity, the other about its importance. The firsts thatin these casesthe questionabout identity must have an answer. No one thinksthisabout, say,nations ormachines. Our criteria forthe identityof thesedo not cover certaincases.No one thinks that in these cases the questions "Is it the same nation?" or "Is it the same machine?"musthave answers. Somepeoplebelievethat inthisrespectthey aredifferent.They agree that our criteria of personalidentity do not cover certain cases, but they believe that the nature of their own identity through time is, somehow, such as to guarantee that in these casesquestions about theiridentitymusthave answers. This belief might be expressed as follows"Whateverhappens between now and any future time,either Ishall still exist, oshallnot. Any future experiencewill eitherbemyexperience, oritwill not." Thisfirstbelief-inthe specialnature ofpersonalidentity-has, I think, certaineffects.It makespeople assumethat the principle ofself-interestis morerationallycompellingthan any moral prin- ciple.And it makesthem more depressedby the thought ofaging and of death. 1I have been helped in writing this by D. Wiggins, D. F. Pears, P. F. Strawson,. J. Ayer,. Woods, N. Newman,and (through his publications) S. Shoemaker. 3 DEREK PARFIT I cannot see how to disprovethis firstbelief. I shall describea problemcase. But this can only makeit seemimplausible. Another approach might be this. We might suggest that one cause ofthe beliefisthe projectionofour emotions.Whenwe ima- gine ourselvesin a problem case, we do feel that the question "Would itbe me ?" musthave an answer.But what we take to be a bafflementabout a furtherfact may be only the bafflement of our concern. I shall not pursue this suggestionhere. But one cause of our concern isthe beliefwhichis my secondtarget.This isthat unless the question about identity has an answer, we cannot answer certain important questions (questions about such matters as survival, memory, and responsibility). Against thissecondbelief my claim will be this.Certain impor- tant questions do presuppose question about personalidentity. But they can be freedof this presupposition.And when they are, the questionabout identityhas no importance. I We can startby considering the much-discussedcaseofthe man who, likean amoeba,divides.2 Wiggins has recently dramatized this case.3He first referred to the operation imagined by Shoemaker.4 We suppose that my brain is transplantedinto someone else's (brainless) body, and thatthe resultingperson has my characterand apparentmemories 2 ImplicitnJohn Locke, EssaConcerninHgumanUnderstandinge, . byJohn W. Yolton (London,i96i),Vol. II, Ch.XXVII, sec. i8,and discussedby (among others) A. N. Priorin "Opposite Number," Reviewof Metaphysics, II (I957-I958),and "Time, Existence and Identity," Proceedsf theAris- totelianSociety,LV(i965-i966)J. Bennettin "The Simplicityf thSoul," journalof PhilosophLXIV (i967);and R. Chisholm and S. Shoemaker in "The Loose and Popular and the Strict and the Philosophical Senses of Identity," in Perceptionand PersonalIdentity:Proceedingsi967hOberlin Colloquium Philosophed. by Norman CareandRobert H.Grimm (Cleveland, I937). 4In Identityd Spatio-7Temporalntinui(Oxford,i967),p.50. In Self-KnowledendSelf-Identity(Ithaca, Ni963),p.22. 4 PERSONAL IDENTITY of my life.ost of uswould agree, after thought, that the resulting person is me. I shall here assume such agreement.5 Wiggins then imagined his own operation. My brain is divided, and each half ishoused in a new body. Both resulting people have my character and apparent memories of my life. What happens to me? There seem only three possibilities:(i) I do not survive; (2) I survive as one of the two people; (3) I survive as both. The trouble with (i) isthis. We agreed that I could survive if my brain were successfully transplanted. And people have in fact survived with half their brains destroyed. It seems to follow that I could survive if halfmy brain were successfully transplanted and the other half were destroyed. But ifthis isso, how could I not survive if the other half were also successfully transplanted? How could a double success be a failure? We can move to the second description. Perhaps one success is the maximum score.Perhaps I shallbe one of the resulting people. The trouble here is thatinWiggins' case each half of my brain is exactly similar, and so,to start with, is each resulting person. So how can I survive asonly one of the two people? What can make me one of them rather than the other? It seems clear that both of these descriptions-that I do not survive, and that I survive as one of the people-are highly implausible. Those who have accepted them must have assumed that they were the only possible descriptions. What about our third description: thatI survive as both people ? Itmight be said, "If 'survive' implies identity, thisdescription makes no sense-you cannot be two people. Ifit does not, the description is irrelevant toaproblem about identity." I shall later deny the second of these remarks. But there are ways of denying the first. We might say, "What we have called 'the two resulting people' are not two people. They are one person. 5 Those who would disagree arnot making a mistake. For them my argu- ment would need a differencase. Theremust be some multiple transplant, facedwith which thespeoplewould both findithardtobelievethat theremust be an answerto thequestionabout personalidentity,nd be abletobe shown that nothingofimportance turnsupon this question. 5 DEREK PARFIT I do survive Wiggins' operation. Its effect is to give me two bodies and a divided mind." It would shorten my argument if this were absurd. But I do not think it is. It worth showing why. We can, Isuggest, imagine a divided mind. We can imagine a man having two simultaneous experiences, in having each of which he is unaware of having the other. We may not even need to imagine this. Certain actual cases, to which Wiggins referred, seem to be best described in these terms. These involve the cutting of the bridge between the hemispheres of the brain. The aim was to cure epilepsy. But the result appears to be, in the surgeon's words, the creation of "two separate spheres ofconsciousness," each of which controls one half of the patient's body. What is experienced in each is, presumably, experienced by the patient. There are certain complications in these actual cases. So let us imagine a simpler case. Suppose that the bridge between my hemispheres is brought under my voluntary control. This would enable me to disconnect my hemispheres as easilyas if I were blinking. By doing this I would divide my mind. And we can suppose that when my mind is divided I can, ineach bring about reunion. half, This abilitywould have obvious uses. To give an example: I am near the end of a maths exam, and see two ways of tackling the lastproblem. Idecide to divide my mind, towork, with each half, at one of two calculations, and then to reunitemy mind and write a faircopy of the best result. What shallI experience? When I disconnect my hemispheres, my consciousness divides into two streams. But this division is notsomething that I expe- rience. Each of my two streams ofconsciousness seems to have been straightforwardly continuous with my one stream of conscious- ness up tothe moment of division.he only changes ineach stream are the disappearance ofhalf my visual field and the lossof sen- sation in,and control over,half my body. 6R. W. Sperry,inBrainand ConscibuExperience,. by J. C.ccles (New York, 1966), p.99. 6 PERSONAL IDENTITY Consider my experiences in what we can callmy "right-handed" stream. I remember that I assigned my right hand to the longer calculation. This I now begin. In working at this calculation I can see, from the movements of my left hand, that I am also working at the other. But I am not aware of working at the other. So I might, in my right-handed stream, wonder how, in my left-handed stream, I am getting on. My work is now over. I am about to reunite my mind. What should I, in each stream, expect? Simply that I shall suddenly seem to remember just having thought out two calculations, in thinking out each of which I was not aware of thinking out the other. This,Isubmit, we can imagine. And ifmy mind was divided, these memories are correct. In describing this episode,I assumed that there were two series of thoughts, and that they were both mine. If my two hands visiblywrote out two calculations, and ifI claimed to remember two corresponding series of thoughts, this is surely what we should want to say. Ifit is, then person's mental history need not be likea canal, with only one channel. It could be like a river,with islands, and with separate streams. To apply this to Wiggins' operation: we mentioned the view that itgives me two bodies and a divided mind. We cannot now call thisabsurd. But it is,I think, unsatisfactory. There were two features of thecase of the exam that made us want to say that only one person was involved. The mind was soon reunited, and there was only one body. If a mind was permanently divided and its halves developed in different ways, the point of speaking of one person would start to disappear. Wiggins'case, where there are also two bodies, seems to be over the borderline. After I have had his operation, the two "products" each have all the attributes of a person. They could live at opposite ends of the earth. (If they later met, they might even fail to recognize each other.)It would become intolerable to deny that they were different people. Suppose we admit thatthey are differentpeople. Could we still claim that Isurvived asboth, using "survive" to imply identity? We could. For we might suggest that two people could compose 7 DEREK PARFIT a third. We might say, "I do survive Wiggins' operation as two people. They can be different people, and yet be me, in just the in which the three crowns are one crown."7 way Pope's This isa possible way of giving sense to the claim that I survive as two different people, using "survive" to imply identity. But it keeps the language of identity only by changing the concept of a person. And there are obvious objections to thischange.8 The alternative, for which I shall argue, is to give up the lan- guage of identity. We can suggest that I survive as two different people without implying that I am these people. When I first mentioned this alternative, I mentioned this objec- "If tion: your new way of talking does not imply identity, it cannot solve our problem. For that isabout identity. The problem isthat allthe possible answers to the question about identity are highly implausible." We can now answer this objection. We can start by reminding ourselves that this is an objection only ifwe have one or both of the beliefs which I mentioned at the start of this paper. The firswas the belief that to any question about personal iden- tity, in any describable case, there must be a true answer. For those with this belief, Wiggins' case isdoubly perplexing. If all the possible answers are implausible, it ishard to decide which of them is true, and hard even to keep the belief that one of them must be true. If we give up this belief, as I think we should, these problems disappear. We shall then regard the case as like many others in which, for quite unpuzzling reasons, there is no answer to a question about identity. (Consider "Was England the same nation after io66 ?") Wiggins' case makes the firstbelief implausible. It also makes 7Cf. David Wiggins,op.Cit,. 40. 8 Suppose theresultingpeople fightduel. Are there threpeople fighting, one on each side, and one on both? And suppose oneofthe bullets kills. Are there two acts, one murderand one suicide? Howmany people are left alive? One? Two? (We could hardly say, "One and ahalf.")We could talk in this way. But insteadofsaying thathe resultingpeople areheoriginalperson-so that the pair is a trio-it would be far simpler to treat them as a pair, and describe theirelation to the original person some new way. (I owe this suggestedway of talking,and the objectionsto itMichael Woods.) 8 PERSONAL IDENTITY it trivial. For it undermines the second belief. This was the belief that important questions turn upon the question about identity. (Itis worth pointing out that those who have only this second belief do not think that there must be an answer to this question, but rather that we must decide upon an answer.) Against thissecond belief my claim is this. Certain questions do presuppose a question about personal identity. And because these questions areimportant, Wiggins' case does present aproblem. But we cannot solve this problem by answering the question about identity. We can solvethis problem only by taking these important questions and prizing them apart from the question about identity. After we have done this, the question about identity (though we might for the sake of neatness decide it)has no further interest. Because there are several questions which presuppose identity, this claim will take some time to fillout. We can first return to thequestion of survival. This isa special case, for survival does not so much presuppose the retaining of identity as seem equivalent to it. It is thus the general relation which we need to prize apart from identity.We can then consider particular relations, such as those involved in memory and inten- tion. "Will I survive?" seems, I said, equivalent to "Will there be some person alive who is the same person as me?" If we treat these questions as equivalent, then the least unsatisfactory description of Wiggins' case is,I think, that I survive with two bodies and a divided mind. Several writers have chosen to say that I am neither of the resulting people. Given our equivalence, this implies that I do not survive, and hence, presumably, that even ifWiggins' operation is not literally death,Iought, since I will not survive it, to regard it as death. But this seemed absurd. It is worth repeating why. An emotion or attitude can be criticized for resting on a falsebelief, or for being inconsistent. A man who regarded Wiggins' operation asdeath must, Isuggest, be open to one of these criticisms. He might believe that his relation to each of the resulting people fails tocontain some element which is contained in survival. But how can this be true? We agreed that he wouldsurvive ifhe 9 DEREK PARFIT stood in this very same relation toonly oneof the resulting people. So it cannot be the nature of this relation which makes it fail, in to be survival. Itcan only be its duplication. Wiggins' case, Suppose that our man accepts this, but stillregards division as death. His reaction would now seem wildly inconsistent. He would be likea man who, when told ofa drug that could double his years of life, regarded the taking of thisdrug as death. The only differ- ence in the case of division isthat the extra years are to run con- currently. This is an interesting difference. But it cannot mean that there are no years to run. Ihave argued this for those who think that there must, in Wig- gins' case, be a true answer to the question about identity. For them, we might add, "Perhaps the original person does lose his identity. But there may be other ways to do this than to die. One other way might be to multiply. To regard these as the same is to confuse nought with two." For those who think that the question of identity isup for decision, itwould be clearly absurd to regard Wiggins' operation as death. These people would have to think, "We could have chosen to say that I should be one of the resulting people. If we had, I should not have regarded it asdeath. But since we have chosen to say that Iam neither person, I do." This ishard even to understand.9 My firstconclusion, then, is this. The relation of the original person to each of the resulting people contains all that interests us-all that matters-in any ordinary case of survival. This is why we need a sense in which one person can survive as two.10 One of my aims in the rest of thispaper will be to suggest such a sense. But we can first make some general remarks. II Identity isa one-one relation.Wiggins' case serves to show that what matters in survival need not be one-one. 9 Cf. Sydney Shoemaker, in PerceptiandPersonalIdentity:oceedingsfthe 1967 OberlinColloquimn Philosophloc.cit. 10Cf. David Wiggins, op.cit.,54. I0 PERSONAL IDENTITY Wiggins' case isof course unlikely to occur. The relations which matter are, in fact, one-one. It is because they are that we can of relations by using the language of imply the holding these identity. This use of language is convenient. But it can lead us astray. We may assume that what matters is identity and, hence, has the properties of identity. In the case of the property of being one-one, this mistake is not serious. For what matters is in fact one-one. But in the case of another property, the mistake is serious. Identity is all-or-nothing. Most of the relations which matter in survival are, in fact,relations of degree. If we ignore this, we shall be led into quite ill-grounded attitudes and beliefs. The claim that I have just made-that most of what matters are relations of degree- I have yet to support. Wiggins' case shows only that these relations need not be one-one. The merit of the is not it shows this in particular, but that it makes the case that first break between what matters and identity. The belief that identity is what matters ishard to overcome. This is shown in most discussions of the problem cases which actually occur: cases, say, of amnesia or of brain damage. Once Wiggins' case has made one breach in this belief,the rest should be easier to remove. To turn to a recent debate: most of the relations which matter can be provisionally referred to under the heading "psychological continuity" (which includes causal continuity). My claim is thus that we use the language of personal identity in order to imply 11 Bernard Williams' "The Self and the Future," PhilosophicaReview, LXXIX (1970), i6i-i8o, is relevanthere. He asks the question"Shall I naturalit is tolieve survive?" in arange ofproblem cases,and he showshow (i) thatthis questionmust have an answer, (2) thatthe answer must be all- or-nothing, and (3) that thereis a "risk"of our reaching thewrong answer. Because these beliefsre sonatural, we should need inundermining them to discuss theircauses.These, I think,can be found in theways inwhich we misinterpret what it is to remember (cf.Sec. III below) and to anticipate (cf.illiams' "Imagination and the Self," Proceedings theBritishAcademy, LII [I966],105-124); and also in theway in which certain features of our egoisticconcern-e.g., that it isimple,and appliesto all imaginablecases- are "projected" onto itsobject.(Foranother relevantdiscussion,see Terence Penelhum's SurvivalandDisembodied Existence[London, 1970], final chapters.) II DEREK PARFIT such continuity. This is close to the view that psychological continuity provides a criterion of identity. Williams has attacked this view with the following argument. Identity is a one-one relation. So any criterion of identity must appeal toa relation which is logically one-one. Psychological conti- nuity is not logically one-one. So it cannot provide a criterion.12 Some writers have replied that it is enough if the relation appealed to isalways in fact one-one.13 I suggest a slightly different reply. Psychological continuity is a ground for speaking of identity when it is one-one. If psychological continuity took a one-many or branching form, we should need, I have argued, to abandon the language of identity. So this possibility would not count against this view. We can make a stronger claim. This possibilitywould count in its favor. The view might be defended as follows.Judgments of personal identity have great importance. What gives them their importance is the fact that they imply psychological continuity. This is why, whenever there is such continuity, we ought, ifwe can, to imply it by making a judgment of identity. If a psychological continuity took branching form, no coherent set ofjudgments of identity could correspond to,and thus be used to imply, the branching form of this relation. But what we ought to do, in such a is take case, the importance which would attach to a judgment of identity and attach this importance directly to each limb of the branching relation. So this case helps to show that judgments of personal identity do derive their importance from the fact that they imply psychological continuity. It helps to show that when we can, usefully, speak ofidentity, this relation is our ground. This argument appeals to a principle which Williams put forward.14 The principle is that an important judgment should be asserted and denied on different only importantly grounds. 12"Personal Identityand Individuation," Proceedingsofthe Aristotelian Society, VII(1956-i957),229-253; alsoAnalysis,i (i960-i961),43-48. 13J. M. Shorter, "More about Bodily Continuityand Personal Identity," Analysis22 (i96i-i962),79-85; and Mrs. J.M. R. Jack (unpublished),who requiresthat thistruthbembedded in a causaltheory. 14Analysis21 (i960-i96i),44. 12 PERSONAL IDENTITY Williams applied this principle to a case in which one man is psychologically continuous with the dead Guy Fawkes, and a case in which two men are. His argument was this. If we treat psycholog- ical continuity as a sufficient ground for speaking of identity, we shall say that the one man isGuy Fawkes. But we could not say that the two men are, although we should have the same ground. This disobeys the principle. The remedy is to deny that the one man is Guy Fawkes, to insist that sameness of the body is necessary for identity. Williams' principle can yield a different answer. Suppose we regard psychological continuity as more important than sameness of the body.'5 And suppose that the one man really ispsychologi- cally (and causally) continuous with Guy Fawkes. Ifhe is,t would disobey the principle todeny that he is Guy Fawkes, forwe have the same important ground as in a normal case of identity. In the case of the twomen, we again have the same important ground. So we ought to take theimportance from the judgment of identity and attach itdirectly to thisground. We ought to say,as in Wig- gins' case, that eachlimb of the branching relation is as good as survival. This obeys the principle. To sum up these remarks: even ifpsychological continuity is neither logically,nor always in fact,one-one, it can provide a criterion of identity. For this can appeal to the relation of non-branchingpsychological continuity,which islogicallyone-one.16 The criterion might be sketched as follows. "X and r are the same person if are they psychologically continuous and there is no person who iscontemporary with either and psychologically continuous with the other." We should need to explain what we mean by "psychologically continuous" and say how much conti- nuity the criterion requires. We should then, I think, have de- scribed a sufficient condition for speaking of identity.17 We need to say something more. Ifwe admit that psychological 15For the reasonsgiven by A. M. Quintonn "The Soul," JournalofPhilos- ophy,LIX (I962)393-409. 16Cf. S. Shoemaker,"Personsand Their Pasts," to appear in the American Philosophicl uarterlya,nd "Wigginson Identity,"osophicl evieLXXIX (I970),542. 17But nota necessary condition, for the absence of psychologiconti- nuity bodily identity might be sufficient. I3 DEREK PARFIT continuity might not be one-one, we need to say what we ought to do if iwere not one-one. Otherwise our account would be open to the objections that it iincomplete and arbitrary.18 I have suggested that if psychological continuity took a branch- ing form, we ought to speak in a new way, regarding what we describe as having the same significance as identity. This answers these objections.19 We can now return to our discussion. We have three remaining aims. One is tosuggest a sense of "survive" which does not imply identity. Another is to show that most of what matters in survival A are relations of degree. third is to show that none of these relations needs to be described ina way that presupposes identity. We can take these aims in the reverse order. III The most important particular relation is that involved in memory. This isbecause it is so easy tobelieve that itsdescription must refer to identity.20This belief about memory is an important cause of the view that personal identity has a special nature. But it has been well discussed by Shoemaker2l and by Wiggins22 So we can be brief. It may be a logical truth that we can only remember our own experiences. But we can frame a new concept for which this is not a logical truth. Let us callthis "q-memory." 18 Cf.Bernard Williams,"Personal Identity and Individuation,"roceedings 240-24I, and Analysis2I (1960- of theAristoteliSociety,LVII (I956-I957), I961),44; andalsoWiggins,op.cit.,. 38:" icoincidence under [the concept] f is to be genuinsufficientwe mustnot withhold identity ... simply because transitivitysthreatened." 19Williams produced another objectionto the "psychologicalcriterion," thatit makesit hard texplain thedifferencebetween the conceptsfidentity and exact similarity (Analys2I, [i960-i96I],48). But if we include the requirement of causal continuitywe avoid this objection (and one of those produced by Wigginsin his note 47). 20Those philosopherswho have held this belief,rom Butler onward, are too numerousto cite. 21Op. cit. 22In apaper onButler'sobjectionto Locke (notyet published). I4 PERSONAL IDENTITY To sketch a definition23I am q-remembering an experience if (i) I have a belief about a past experience which seems in itself like a memory belief, (2)someone did have such an experience, and (3) my belief is dependent upon this experience in the same way (whatever that is)in which a memory of an experience isdepen- dent upon it. According to (i) q-memories seem like memories. So I q-remem- ber having experiences. This may seem to make q-memory presuppose identity. One might say, "My apparent memory of having an experience is an apparent memory of my having an experience. So how could I q-remember my having other people's experiences?" This objection restson a mistake. When Iseem to remember an experience, I do indeed seem to remember having it.24But it cannot be a part ofwhat I seem to remember about thisexperience that I, the person who now seems to remember it,am the person who had this experience. That I am is something that I auto- matically assume. (My apparent memories sometimes come to me simply as the belief that I had a certain experience.) But it is something that I am justifiedin assuming only because Ido not in fact have q-memories of other people's experiences. Suppose that I did start to have such q-memories. If I did, I should cease to assume that my apparent memories must be about my own experiences. I should come to assess an apparent memory by asking two questions: (i) Does it tellme about a past experience? (2) Ifso, whose? Moreover (and this isa crucial point) my apparent memories would now come to me as q-memories. Consider those of my ap- 23J here follow Shoemaker's"quasi-memory." Cf. also Penelhum's "retro- cognition,"in hisarticle onPersonal Identity,"n theEncyclopediafPhilos- ophy,ed.by Paul Edwards. 24As Shoemaker put it, I seem to remember the experience "from the inside" (op.cit.). 25This is what so many writers have overlooked.f. Thomas Reid: "My memory testifiesnoonlythat this was done, buthat it was donby me who now remember it" ("Of Identity," in EssaysontheIntellectul owersof Man, ed. by A. D. Woozley [London, I94I], p.203).This mistake is discussedby A. B. Palma in "Memory and Personal Identity," AustralasiaJournalof Philosophy2 (I964),57. I5 DEREK PARFIT parent memories which do come to me simply as beliefs about my past: for example, "I did that." If knew that Icould q-remember other people's experiences, these beliefs would come to me in a more guarded form: for example, "Someone-probably I-did that." I might have to work out who it was. I have suggested that the concept of q-memory is coherent. Wiggins' case provides an illustration. The resulting people, in his case, both have apparent memories of living the life of the original person. If they agree that they are not this person, they will have to regard these as only q-memories. And when they are asked a question like "Have you heard this music before?" they might have to answer "I am sure that I q-remember hearing it. But I am not sure whether I remember hearing it.I am not sure whether it was I who heard it,or the original person." We can next point out that on our definition every memory is also a q-memory. Memories are, simply, q-memories ofone's own experiences. Since this is so, we could afford now to drop the concept of memory and use in its place the wider concept q-memory. Ifwe did, we should describe the relation between an experience and what we now call a "memory" of this experience in a way which does not presuppose that they are had by the same person 26 This way of describing this relation has certain merits. It vindicates the "memory criterion" of personal identity against the charge of circularity.27And it might, I think, help with the problem of other minds. 26 Itinot logicallyecessarythat weonly q-rememberourown experiences. But it might be necessaryon other grounds.This possibilitys intriguingly explored by Shoemaker in his "Personsnd Their Pasts" (op. citHe. shows that q-memoriescan providea knowledge of the worldnly if the observations which are q-remembered trace out fairly continuous spatiotemporalths. If the observationsich areq-remembered tracedout anetworkof frequently interlockingaths, they couldnot, I think,e usefullyascribed to persisting observers,but would haveto be referredo in some moreomplex way. But in factthe observationswhich are q-remembered trace outsingle andseparate paths; so wecan ascribethem to ourselves.n other words,t is epistemologi- callynecessarythat the observationswhichare q-remembered shouldsatisfy a certain generalondition,one particularform of whichallows them to be usefullyself-ascribed. 27Cf. Wiggins'paper on Butler'sobjectiono Locke. i6 PERSONAL IDENTITY But we must move on. We can next take the relation between an intention and a later action. It may be a logical truth that we can intend to perform only our own actions. But intentions can be redescribed as q-intentions. And one person could q-intend to perform another person's actions. Wiggins' case again provides the illustration.e are supposing that neither of the resulting people is the original person. If so, we shall have to agree that the original person can, before the operation, q-intend to perform their actions. He might, for exam- ple, q-intend, as one of them, to continue hispresent career,and, as the other, to try something new.28 (I say "q-intend as one of them" because the phrase "q-intend that one of them" would not convey the directness of the relation which isinvolved. If Iintend that someone else should do something, I cannot get him to do it simply by forming this intention.But if I am the original person, and he is one of the resulting people, I can.) The phrase "q-intend as one of them" reminds us that we need a sense in which one person can survive as two. But we can first point out that the concepts of q-memory and q-intention give us our model for the others that we need: thus, a man who can q-remember could q-recognize, and be a q-witness of, what he has never seen; and a man who can q-intend could have q-ambitions, make q-promises, and be q-responsible for. To put thisclaim ingeneral terms: many different relations are included within, or are a consequence of,psychological continuity. We describe these relations in ways which presuppose the contin- ued existence of one person. But we could describe them in new ways which do not. This suggests a bolder claim. It might be possible to think of experiences in a wholly "impersonal" way. I shall not develop 28There are complicationshere.He couldform divergent-intentionsnlyif he could distinguish,nadvance, between theresulting people(e.g.,s"the left-hander"and "the right-hander").nd he could be confidentthatsuch divergentq-intentionsould be carriedouonly ihe had reasontobelievehat neitherof the resulting peopleuld change their (inherited)nd. Suppose he was torn betweenduty and desire.He could notsolve thisilemma by q- intending,as one of tresultingpeople,o dohisduty, and,s theother,to do what he desires.or theone he q-intendedo do hisdutywould facethe same dilemma. I7 2 DEREK PARFIT this claim here. What I shall try todescribe is a way of thinking of our own identity through time which is more flexible,and less misleading, than the way in which we now think. This way of thinkingwill allow for a sensein which one person can survive as two. A more important feature is that it treats survival as a matter of degree. IV We must first show the need for this second feature. I shall use two imaginary examples. The firstis the converseof Wiggins' case: fusion.Justas division serves to show that what matters in survival need not be one-one, so fusionserves to show that itcan be a question ofdegree. Physically,fusion is easyo describe.Two people come together. While they are unconscious, theirtwo bodies grow into one. One person then wakes up. The psychology of fusion is more complex. One detail we have already dealt with in the case of the exam. When my mind was reunited, I remembered justhaving thought out two calculations. The one person who results from a fusioncan, similarly, q-remem- None of their ber living the lives ofthe two original people. q- memories need be lost. But some things must be lost. For any two people who fuse together will have different characteristics,different desires,and different intentions.How can these be combined? We might suggest the following. Some of these willbe compat- ible. These can coexist in the one resulting person. Some will be incompatible. These, if of equal strength, can cancel out, and if of differentstrengths, the stronger can be made weaker. And all these effectsmight be predictable. To give examples-first, of compatibility: I like Palladio and a who likes intend to visitVenice. I am about tofuse with person Giotto and intends to visitadua. I can know that the one person we shall become will have both tastesand both intentions.Second, of incompatibility: I hate red hair, and always vote Labour. The other person lovesred hair, and always votes Conservative. I can I8 PERSONAL IDENTITY know that the one person we shall become will be indifferent to red hair, and a floating voter. If we were about to undergo a fusion of this kind, would we regard itas death? Some of us might. This is less absurd than regarding division as death. For after my division the two resulting people will be in every way like me, while after my fusion the one resulting person will notbe wholly similar.This makes iteasier to say, when faced with fusion,"I shall not survive," thus continuing to regard survival as a matter of all-or-nothing. This reaction is less absurd. But here are two analogies which tell againstit. First,fusion would involve the changing of some of our charac- teristicsand some of our desires. But only the very self-satisfied would think of this as death. Many people welcome treatments with these effects. Second, someone who is about to fuse can have, beforehand, just as much "intentional control" over the actionsof the resulting individual assomeone who is about to marry can have, beforehand, over the actions of the resulting couple. And the choice of a partner for fusion can be just as well considered as the choice of a marriage partner. The two original people can make sure (per- haps by "trialfusion") that they do have compatible characters, desires, and intentions. I have suggested that fusion,while not clearly survival, isnot clearly failure tosurvive, and hence that what matters in survival can have degrees. To reinforce this claim we can now turn to a second example. This is provided by certain imaginary beings. These beings are just like ourselves except that they reproduce by a process of natural division. We can illustrate the historiesof these imagined beings with the aid ofa diagram. (This isgiven on the next page.) The lines on the diagram represent the spatiotemporal paths which would be traced out by the bodies of these beings. We can call each single line (likethe double line)a "branch"; and we can call the whole structure a "tree." And let ussuppose that each "branch" corresponds to what is thought of as the life of one individual. '9 DEREK PARFIT 4 Space-_ B+15 B+30 8+7 8~~~~~~~~+14 t (later) + B+2+2 Time FA 4 earlier These individuals are referred to as "A," "B+I," and so forth. each single division isan instance of Wiggins' case. So Now, A's relation to both B + i and B + 2 is justs good as survival. But what of A's relation to B+30? Isaid earlier that what matters in survival could be provision- ally referred to as "psychological continuity." I must now dis- tinguish thisrelation from another, which I shallcall "psychologi- cal connectedness." Let us say that the relation between a q-memory and the expe- rience q-remembered is a "direct" relation. Another "direct" relation is that which holds between a q-intention and the q- intended action. A third is that which holds between different expressions of some lasting q-characteristic. "Psychological connectedness," as I define it,equires the hold- ing of these direct psychological relations. "Connectedness" these relations are not transitive.Thus, if is not transitive,since X q-remembers most of r's life,nd r q-remembers most of Z's life,itdoes not follow that X q-remembers most of Z's life.nd if X carries out the q-intentions ofY. and r carries out the q-inten- tions ofZ, it does not follow that X carries out the q-intentions of Z. "Psychological continuity," in contrast, only requires overlap- is ping chains of direct psychological relations.So "continuity" transitive. To return to our diagram. A is psychologicallycontinuous with B + 30.There are between the two continuous chains of overlap- 20 PERSONAL IDENTITY ping relations. Thus, A has q-intentional control over B + 2, B + 2 has q-intentional control over B + 6, and so on up to B + 30. Or B + 30 can q-remember the life of B + I4, B + I4 can q-remember the lifeof B + 6, and so on back to A.29 A, however, need not be psychologically connected to B + 30. Connectedness requires direct relations. And ifthese beings are like us, A cannot stand in such relations to every individual in hisindefinitely long "tree." Q-memories will weaken with the passage of time, and then fade away. Q-ambitions, once fulfilled, willbe replaced by others.Q-characteristics willgradually change. In general, A stands in fewer and fewer direct psychological relations to an individual in his "tree" the more remote that individual is. And if the individual is (like B + 30) sufficiently remote, there may be between the two no direct psychological relations. Now that we have distinguished the general relations ofpsycho- logical continuity and psychological connectedness, Isuggest that connectedness is amore important element insurvival. As a claim about our own survival, thiswould need more arguments than I have space to give.But it seems clearly true for my imagined beings. A is as closepsychologically to B + i as I today am to myself tomorrow. A is as distant from B + 30 as I am from my great-great-grandson. Even if connectedness is not more important than continuity, fact is a the that one of these relation ofdegree is enough to show that what matters insurvival can have degrees. And in any case the two relations are quite different. So our imagined beings would need a way of thinking in which this difference isrecog- nized. V I is this. What propose First,A can think of any individual, anywhere in his "tree," as "a descendant self." This phrase implies psychological conti- nuity. Similarly, any later individual can think of any earlier 29 of run in one of 2 is The chain continuityust direBtion time.B + not,in the sense intend, psychologicallytinuouswith + I. 21 DEREK PARFIT individual on the single path30 which connects him to A as "an ancestral self." Since psychological continuity is transitive,"being an ancestral self of"and "being a descendant self of" are also transitive. To imply psychological connectedness I suggest the phrases "one of my future selves" and "one of my past selves." These are the phrases with which we can describe Wiggins' case. For having past and future selves is, what we needed, a way of continuing to exist which does not imply identity through time. The original person does, in this sense, surviveWiggins' operation: the two resulting people are his later selves.And they can each refer tohim as "my past self."(They can share a past self without being the same self aseach other.) Since psychological connectedness is not transitive, and is a matter of degree, the relations "being a past selfof" and "being a future self of" should themselves be treated as relations of degree. We allow for this series of descriptions: "my most recent self," "one of my earlier selves," "one of my distant selves," "hardly one of my past selves (I can only q-remember a few of his expe- riences)," and, finally, "not in any way one of my past selves- just an ancestral self." This way of thinking would clearly suit our first imagined beings. But let us now turn to a second kind of being. These reproduce by fusion as well as by division.31And let us suppose that they fuse every autumn and divide every spring. This yields the following diagram: -Space-* / /+lr spring Time ) /p autumn A autumn 30Cf. David Wiggins,op.cit. 31Cf. Sydney Shoemakerin "Persons and Their Pasts,"op.cit. 22 PERSONAL IDENTITY If A is the individual whose life is representedby the three- lined "branch," the two-lined "tree"representsthose liveswhich are psychologicallycontinuouswith A'slife. (It can be seen that each individual has his own "tree,"which overlapswith many others.) For the imagined beings inthis secondworld, the phrases"an ancestralself" and "a descendant self"would cover too much to be ofmuch use. (Theremay wellbe pairsof datessuchthat every individual who ever lived before the firstdate was an ancestral self oevery individual who ever will liveafterthe second date.) Conversely, since the lives of each individual last only halfa year, the word "I" would cover too little to doallof the work which it does forus.So part ofthis workwould have tobe done, forthesesecond beings,by talkabout past and future selves. We can now point out a theoreticalflaw in ourproposedway of thinking. The phrase "a past self of"implies psychological connectedness. Being past selof treatedasa relationf degree, so that thisphrase can be used to imply the varying degrees of psychological connectedness. But thisphrase can imply only the degrees of connectedness between different lives. Itcannot be used within a singlelife. And our way of delimitingsuccessive livesdoes not referto thedegrees ofpsychologicalconnectedness. Hence there is no guarantee that this phrase, "a past selfof," could be used whenever it was needed. There is no guarantee that psychologicalconnectednesswill not vary in degreewithin a life. single This flaw would not concern our imagined beings. For they divide and unite sofrequently,and theirlives arein consequence so short, that within a singlelifepsychological connectedness would always stand at amaximum. But letus look,finally,ata thirdkindof being. In this world there is neitherdivision nor union.There are a numberof everlastingbodies, which graduallychange inappear- ance. And direct psychological relations, as before, hold only over limited periodsof time.This can be illustratedwitha third diagram (given on the next page). In this diagram the two shadingsrepresent the degreesof psychological connectedness to their two centralpoints. 23 DEREK PARFIT 4- Space- t Time These beings could not use the way of thinking that we have proposed. Since there is nobranching of psychological continuity, they would have to regard themselves as immortal. It might be said that this is what they are. But there is, I suggest, a better description. Our beings would have one reason for thinking of themselves as immortal. The parts of each "line" are allpsychologically continuous. But the partsof each "line" are not allpsychologically connected. Direct psychological relations hold only between those parts which are close to each other in time. This gives our "line" as corresponding beings a reason for not thinking of each to one single life. For ifthey did, they would have no way of implying these directrelations. When aspeaker says,for example, "I spent a period doing such and such," his hearers would not be entitled to assume that the speaker has any memories ofthis period, that his character then and now are in any way similar, that he is now carrying out any ofthe plans or intentions which he then had, and so forth.Because the word "I" would carry none of these implications, it would not have for these "immortal" beings the usefulness which it has forus.32 To gain a better way of thinking, we must revise the way of thinking that we proposed above. The revision is this.The dis- tinction between successive selves can be made by reference, not but to the degrees to the branching of psychological continuity, 82 28 (I967-1968), Cf.Austin Duncan Jones, "Man's Mortality,"Analysis, 65-70. 24 PERSONAL IDENTITY of psychological connectedness. Since this connectedness is a matter of degree, the drawing of these distinctions can be leftto the choice of the speaker and be allowed to vary from context to context. On this way ofthinking, the word "I" can be used to imply the greatest degree of psychological connectedness. When the connec- are reduced, when there has been any marked change of tions character or styleof life,r any marked lossof memory, our imag- ined beings would say,"It was not I who did that, but an earlier self."They could then describe in what ways, and to what degree, they are related to this earlierelf. This revised way of thinking would suit not only our "immortal" beings. It is alsohe way in which we ourselves could think about natural. our lives.And itis,I suggest, surprisingly One of its features,the distinction between successive selves, has already been used by several writers. To give an example, from Proust: "we are incapable, while we are in love, of acting as fit predecessorsof the next persons who, when we are inlove no longer, we shall presently have become. . .. Although Proust distinguished between successive selves, he selves.This still thought of one person as being these different we would not do on the way of thinking that I propose. IfI say, "It will not be me, but one of my future selves,"I do not imply that I willbe that future self.e is one ofmy laterselves,and I am one of his earlierselves.There is no underlying person who we both are. To point out another feature of thisway of thinking. When I say, "There is no person who we both are," I am only giving my decision.Another person could say,"It will be you," thus deciding differently.There is no question of either of thesedecisions being a mistake. Whether tosay "I," or "one of my future selves," or "a descendant self"is entirely a matter of choice. The matter of fact,which must be agreed, isonly whether the disjunction applies. (The question "Are X and r the same person?" thus becomes "Is X atleastan ancestral[or descendant] selfof r?") 33 I,226 (my own translation). Withina BuddingGrove(London,I949), 25 DEREK PARFIT VI I have tried toshow that what matters in the continued existence of a person are, for the most part, relations ofdegree. And I have proposed a way of thinking in which this would be recognized. I shall end by suggesting two consequences and asking one question. It issometimes thought to be especially rational to act in our own best interests. But I suggest that the principle of self-interest has no force. There are only two genuine competitors in this particular field. One is the principle of biased rationality: do what will best achieve what you actually want. The other isthe principle of impartiality: do what is in the best interests of every- one concerned. The apparent force of the principle of self-interestderives, I think, from these two other principles. The principle of self-interest is normally supported by the principle of biased rationality. This is because most people care about their own future interests. Suppose that this prop is lacking. Suppose that a man does not care what happens to him in, say, the more distant future. To such a man, the principle of self-interest canonly be propped up by an appeal tothe principle of impartiality. We must say, "Even if you don't care, you ought to take what happens to you then equally into account." But for this,as a special claim, there seem to me no good arguments. Itcan only be supported aspart of the general claim, "You ought to take what happens to everyone equally into account."34 The special claim tells a man to grant an equalweight to all the parts of his future. The argument for this can only be that all the parts of his future are equallyparts of his future. This is true. But it is a truth too superficial to bear the weight of the argument. (To give an analogy: The unity of a nation is,in its nature, a matter of degree. It is thereforeonly a superficial truth 34Cf. Thomas Nagel's ThePossibilityof Altruism(OxfoI970),n which the special claims in effedefendedas part of the general claim. 26 PERSONAL IDENTITY that allof a man's compatriots are equallyhis compatriots. This truth cannot support a good argument for nationalism.)35 Ihave suggested that the principle of self-interestas no strength of its own. If this iso, there is no special problem in the fact that what we ought to do can be against our interests. There is only the general problem that itmay not be what we want to do. The second consequence which I shall mention is implied in the first. Egoism, the fear not of near but of distant death, the regret that so much of one's only life should have gone by-these are not, I think, wholly natural or instinctive. They are all strengthened by the beliefs about personal identity which I have been attacking. If we give up these beliefs,they should be weakened. My final question is this. These emotions are bad, and ifwe weaken them we gain. But can we achieve this gain without, say, also weakening loyalty to, or love of, other particular selves? As Hume warned, the "refined reflections which philosophy suggests .. . cannot diminish ... our vicious passions ... without dimin- ishing ... such as are virtuous. They are ... applicable to all our affections. In vain do we hope to direct their influence only to one side."36 That hope is vain. But Hume had another: that more of what is bad depends upon false belief. This is also my hope. DEREK PARFIT All SoulsCollege,Oxford 35The unity of nation we seldomtakeformore thanwhat it is.Thisspartly because we often thinkf nations,not asunits,ut ina more complex way. If we thought ofourselvesin theway that Iproposed,we might be lesslikelyo takeour own identity forre than what itis. We are,orexample, sometimes told,"It is irrationalact againstyour own interests.fterall, it willyou who willregretit." To thise couldreply,"No, not me. Not even one ofmy futureselves.Justa descendant self." 36"The Sceptic," in "Essays Moral, Politicalnd Literary,"Hume's Moral andPoliticaPhilosoph(New York, I959),p. 349. 27