Is Causation Necessary for What Matters in Survival?

Is Causation Necessary for What Matters in Survival?Author(s): Scott CampbellSource: Philosophical Studies: An International Journal for Philosophy in the AnalyticTradition, Vol. 126, No. 3 (Dec., 2005), pp. 375-396Published by: SpringerStable URL: http://www.jstor.org/stable/4321667 .

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Philosophical Studies (2005) 126:375-396 ? Springer 2005 DOI 10.1007/si1098-004-7786-1

SCOTT CAMPBELL

IS CAUSATION NECESSARY FOR WHAT MATTERS IN SURVIVAL?

ABSTRACT. In this paper I shall argue that if the Parfitian psychological criterion or theory of personal identity is true, then a good case can be made out to show that the psychological theorist should accept the view I call "psychological sequentialism". This is the view that a causal connection is not necessary for what matters in survival, as long as certain other conditions are met. I argue this by way of Parfit's own principle that what matters in survival cannot depend upon a trivial fact.

1. INTRODUCTION

In this paper I shall argue that if the psychological theory of personal identity is true, then a good case can be made out to show that the psychological theorist should accept the view I call "psychological sequentialism". This is the view that a causal connection is not necessary for what matters in survival.

2. THE PSYCHOLOGICAL THEORY

The basic claim of the standard psychological theory, as pro- pounded for example by Parfit (1986) and Shoemaker (1984), is that person B at t2 is the same person as A at t, if B is R-related to A (and if there is no other person C who exists at t2, and who is not B, but who is also R-related to A). B is R-related to A if B is psychologically connected and/or continuous with A. B is psychologically connected with A if there are certain sorts of direct causal relations between B's psychological states and A's (Parfit, pp. 205-206, 260-261). B is strongly connected to A, according to Parfit, if there exists between B and A, "at least half the number of direct connections that hold, over every day,



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in the lives of nearly every person" (Parfit, p. 206). And B is psychologically continuous with A if B is strongly connected with A, or there exists overlapping chains of strong connectedness between B and A.

Parfit also makes the radical claim that what matters in the way we normally suppose our continued existence (that is, our identity) to matter is not our continued existence, but is in fact R-relatedness. Unlike identity, which is a one-one relation, A can be R-related to more than one person. For example, A can be R-related to both B and C, neither of whom are A, in the case where A "fissions" into B and C. Parfit uses the term "what matters in survival" to refer to what matters in this way.

3. APPROPRIATE CAUSAL CONNECTIONS

As standardly expressed, the psychological theory is a causal theory. R-relatedness is defined in terms of connectedness, and connectedness is defined in terms of causal relations between certain kinds of psychological states. This is to be expected, given that standard analyses of psychological concepts are causal. For example, a psychological state at t2 only counts as a memory of an experience at t1 if there is an appropriate causal connection between these states. And a memory only persists over time if there exists appropriate causal connections between the relevant states. If the appropriate causal connections do not exist (or if no causal connections at all exist), then the memory does not persist over time. 1

Of course, the psychological concepts that psychological theorists such as Parfit and Shoemaker use are broader than standard psychological concepts. For instance, instead of talking in terms of memory and intention, they talk in terms of "quasi-memory" and "quasi-intention". But these states are supposed to differ from ordinary memories and intentions only in that they can persist across persons (so that, for example, person B can have a quasi-memory that A once had). In all other respects they are supposed to be the same as memories and intentions, and so they are also defined in terms of appropriate causal connections.2 As Shoemaker says:



IS CAUSATION NECESSARY 377

if quasi-remembering is to be as much like remembering as possible then not just any causal chain linking a past cognitive and sensory state with a subsequent quasi-memory can be allowed to count as an [appropriate] causal chain. (1970, p. 278, n. 17. I have replaced Shoemaker's term "quasie" with "quasi" in this quote).

Suppose, for example, that Wayne is reminiscing about his graduation, and this causes him to accidentally jog Garth's elbow, which produces in Garth a fantasy that by an incredible coincidence exactly matches Wayne's reminiscences. (Call this the "graduation case".) Wayne and Garth are not psychologically connected here in respect of these states. Garth does not have a q-memory of Wayne's graduation. Although there is a causal connection here, it is not an appropriate one.

Neither Parfit nor Shoemaker specify what will count as an appropriate causal connection in respect of q-memories, but we can assume that it will include whatever causal connections count as appropriate for memories, plus certain other connections that involve, for example, brain-reading and -writing de- vices.

4. SOME FURTHER POSSIBLE CONSTRAINTS

So according to the standard psychological theory, A at t, and B at t2 are psychologically strongly connected if there exists a certain number of appropriate causal connections between B's psychological states and A's. Suppose that B is the "replica" of A produced by A stepping into a teleporter. Given our earlier definition of R-relatedness, that makes A and B R-related, and so B will have what matters in survival for A.

Parfit, though, considers the issue of whether the fact that the causal connection between A and B here involves an unu- sual element, namely a teleporter, makes a difference. Perhaps, he says, for A and B to be R-related, there must not only be psychological connectedness and/or continuity between A and B, but the normal cause of psychological connectedness must be operating. The normal cause of psychological connectedness is the continued existence of a brain, and so if the normal cause



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is required for R-relatedness, then A and B will not be R-related in this case, because their psychological connectedness does not involve the continued existence of a brain.

In order to avoid pre-judging this issue, Parfit says that A and B are R-related only if A is psychologically connected and/ or continuous with B, and the connectedness and/or continuity has the right kind of cause. He then considers three possibilities as to what the right kind of cause is: the normal cause (i.e. the continued existence of a brain), a reliable cause, or any cause. He calls the three versions of the psychological theory that correspond to each of these possibilities, the "narrow view", the "wide view", and the "widest view" respectively.

It is important to realize that what Parfit is doing here is considering whether there are any additional constraints to be placed upon the causal connection between A and B, over and above the "appropriateness" constraint demanded by the various connectedness relations. So in considering the widest view, for instance, which holds that the right kind of cause is any cause, Parfit does not mean to imply that the widest view theorist holds that just any causal connection between psychological states with the appropriate sort of content will do for connectedness. Parfit does not mean to imply, for instance, that the widest view theorist will hold that the graduation case we considered earlier counts as a case of connectedness. What Parfit is considering here is whether, in addition to there being some appropriate causal connection between A's state and B's state, that connection should be the normal one, a reliable one, or whether there need be no such additional constraint.

That this is what Parfit means is demonstrated by the fact that when he considers the narrow, wide and widest views, he says that the issue here concerns relation R. He does not say that the issue concerns connectedness and/or continuity. And relation R is not the same thing as connectedness and/or continuity - relation R he defines as connectedness and/or continuity with the right kind of cause. Parfit is already supposing that connectedness and/or continuity exists in the cases he is considering. The issue concerns what the right kind of cause of




connectedness and/or continuity is for relation R to hold (see 1986, p. 215, pp. 283-287).

5. THE NARROW VIEW

Parfit argues that the psychological theorist should accept the widest view. My argument for sequentialism is best approached by considering Parfit's arguments for this.

Suppose I am teleported, resulting in the creation of "Rep- lica". Replica is psychologically strongly connected to me. According to the narrow view, though, Replica is not me, and does not contain what matters in survival for me, because the cause involved, teleportation, is not the normal cause of psychological connectedness and/or continuity.

Parfit argues that the narrow view is false - that whether or not the cause of psychological connectedness and/or continuity is the normal cause is irrelevant to what matters in survival. The normal cause of psychological connectedness and/or continuity is the continued existence of a brain, which we do not have in teleportation. To demand the normal cause, though, is to demand that there be a certain form of physical connectedness and/or continuity, as well as psychological connectedness and/or continuity. But if one is a psychological theorist, one must have already agreed that there are good reasons for not demanding that there be any sort of physical connectedness and/ or continuity involved in what matters in survival (see 1986, p. 283).

Moreover, Parfit points out that the brain is only important in normal cases because it is the carrier of psychological connectedness and/or continuity. If it was not the carrier of psychological connectedness and/or continuity, then it would not be important. (Parfit says that what matters here is thus the effect, rather than the cause.) So it is psychological connectedness and/or continuity rather than the brain that is important, and that exists in the case of teleportation, and so we have what matters in survival in teleportation (see 1986, p. 284).



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6. THE WIDE VIEW

The psychological theorist now has to decide between the wide and widest views. The wide view holds that the cause must be a reliable one. But suppose the following happens. An evil sci- entist forces A to teleport. A believes that teleportation is most reliable. Replica therefore thinks that he is A. Replica is then told that the information-transferring process is in fact most unreliable, and it was just luck that it worked in his case. How could it be rational for Replica to subsequently decide that he is not A after all? The fact that the teleportation process usually does not succeed in creating a Replica does not change the fact that in this case it did succeed in creating a Replica. And surely for the psychological theorist who does not accept the narrow view, what is important is the creating of a Replica, not what percentage of times the machine succeeds in creating a Replica. So Parfit says that the reliability of the cause cannot be important to what matters in survival. What is important is that the effect is the required one.

Parfit uses an analogy to support this kind of reasoning (287). I offer my own analogy here, which will better suit my purposes later on. We have a catapult with which we are trying to hurl boxes of medical supplies over a ravine. The catapult rarely succeeds in doing so. However, the fact that this is an unreliable process is irrelevant to the fact than when it succeeds, we have the required result - a box of medical supplies on the other side of the ravine. It would be absurd to say that in such a case we did not get what mattered because the catapulting process is an unreliable one. So while it is certainly rational to want the teleportation process to be reliable (especially if you are about to step into the transmitter), reliability is not relevant to whether the process succeeded or not in a particular case.

Parfit concludes that the psychological theorist should therefore not demand that the cause of connectedness and/or continuity be the normal cause or a reliable cause. In the ab- sence of any other suggestions for additional constraints on the causal connection between A and B over and above those in-




volved in connectedness and/or continuity, he concludes that the psychological theorist should accept the widest view, and allow that all that is required for B to be R-related to A is that B be connected and/or continuous with A.

7. PSYCHOLOGICAL SEQUENTIALISM

I will now argue that the psychological theorist should in effect go "wider" still. I will argue that if the psychological theory is true, then B at t2 can have what matters in survival for A at t1 even though there is no causal connection between B and A. I argue that what matters in survival for A is that B is psychologically sequential with A. I define "psychologically sequential" as follows:

B at t2 is psychologically sequential with A at t1 if and only if either (1) B is psychologically connected and/or continuous with A; or (2) B is not psychologically connected to A or psychologically continuous with A, but B is "quasi-connected" to A; or (3) B is not psychologically connected to A, or psychologically continuous with A, or quasi-connected to A, but there are overlapping chains of psychological connectedness and/or quasi-connectedness between A and B.

"Quasi-connectedness" is defined as follows:

B at t2 is quasi-connected to A at t1 if and only if, while B is not psychologically connected to (or continuous with) A, B's psychological states at t2 are just as they would be if B was psychologically connected to A.

The sequentialist's position entails that a causal connection is not necessary for B at t2 to have what matters in survival for A at t1. The sequentialist will argue their case with the following thought experiment.

Suppose that you step into the teleporter, and your body is scanned and destroyed. The information about your body state is sent to the receiver, and stored in a memory chunk. Suppose that in the next memory chunk there is a randomly generated set of properties set aside for use the next time someone presses the "Produce Random Person" button, and by an incredible coincidence of more-than-astronomical proportions, this



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information exactly resembles the information about your body. Once the receiver has received and stored the information about you, it goes into production mode, and a signal is sent to memory telling it to send the recently-received information about your body to the production unit.

But suppose that a tiny short circuit occurs at this point, and the request is directed to the next memory chunk, which contains the "Random Person" information, and this information is sent to the production unit instead of the information about your old body. Because of this tiny glitch, "Random" is produced instead of Replica. But Random is exactly the same as Replica would have been, had the glitch not occurred. Unlike Replica, Random is not psychologically continuous with you. But Random is psychologically sequential with you.

So we have two possible cases in two different possible worlds: w1, where there is no tiny glitch and Replica is produced, and w2, where there is a tiny glitch and Random is produced. There is no other difference between these two worlds. To argue that I have what matters in survival in (or at) w1 but not in w2 is to argue that this little glitch makes a significant difference. The sequentialist claims that this is incredible. What is more, it conflicts with an important principle of Parfit's, which he uses to support his theory, and which I label

P2

P2: Since what matters in survival is of great significance, whether we have what matters in survival cannot depend on a trivial fact (pp. 267-271).

8. CAN A TINY CAUSAL DIFFERENCE BE IMPORTANT?

An objector might point out that this sort of tiny difference can have significant consequences. For example, a tiny glitch in a circuit could trigger off a nuclear explosion which kills millions of people. So the huge difference between no-one being killed and millions being killed could be due to the same sort of tiny glitch as occurred in w2. So why is there a problem with




such a tiny glitch being the significant difference between w1 and w2?

This reply misses the point, though. In the nuclear bomb example just given, the tiny glitch results in things being entirely different to what they would otherwise have been. However, there are no such large differences between w1 and w2. Exactly the same body is produced, out of exactly the same particles, with exactly the same kind of psychological states.3 The only difference between w1 and w2 is the tiny glitch itself, and the fact that one set of information was used rather than another set of exactly identical information. These facts are trivial facts, though, and so P2 entails that there can be no great difference between w1 and w2 as far as what matters in survival goes. Thus, if we have what matters in survival in w1, we must also have what matters in survival in w2. Random must therefore contain what matters in survival for you, if Replica does. (The situation is like a glitch in a drink machine preventing you getting the can you want, but then by accident such a can comes out anyway.)

9. KOLAK AND MARTIN'S "MOC" ARGUMENT

Two other philosophers, Daniel Kolak and Raymond Martin, have explicitly argued (in 1987) that the psychological theorist should drop the causal requirement, or at least that the psychological theorist should seriously question it. One of their main arguments seems to have a similar form to mine. Suppose teleportation works this way. You are placed in the transmitter, your body is recorded and destroyed, and the information is sent to the receiver. The receiver then randomly constructs objects ("mathematical object-configurations" or "MOCs") until it hits upon one that exactly matches the information received (1987, p. 343).

Kolak and Martin claim that the causal connection here is "weaker" than the connection required by those psychological theorists who accept that teleportation preserves identity and what matters in survival. Nevertheless, they say, such psychological theorists would have to accept that the "MOC Replica"



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here is you, because there is not much difference between this MOC Replica and the "standard" Replica. But if you allow that the MOC Replica is you, then you are allowing that identity and what matters in survival may be preserved with only a very weak causal connection. Kolak and Martin hold that this undermines the claim that a causal connection is necessary for identity and what matters in survival.

However, I would not characterize the causal connection in the MOC case as a "weaker" kind of connection than the connection required by psychological theorists such as Parfit, who accept that teleportation preserves identity and/or what matters in survival. I would say that the MOC teleportation process straightforwardly meets such requirements. The fact that the information transfer between the transmitter and the production unit is more convoluted and indirect than occurs in a standard teleporter does not change the fact that the explicit function of the two types of teleporter is the same, namely for the receiving machine to produce a copy of the body in the transmitter on the basis of the information received from the transmitter.

Kolak and Martin say that this MOC Replica does not "arise out of" you, "nor was it produced from" you (1987, p. 343). It seems to me, though, that this Replica is produced from you (at least, it is if Parfit's Replica is), even if not directly - but causation does not have to be direct. If a boss orders a security guard to lock a door, the boss has caused that door to be locked, even though he did not lock it with his own hands, and even if the process he sets in motion is the guard trying doors at random with his key, until he finds the right one.

So I claim that this argument of Kolak and Martin's does not show that a causal connection is unnecessary for what matters in survival.

10. THE "NEW CLUB" ARGUMENT FOR SEQUENTIALISM

Here is a further argument in support of the sequentialist view. Parfit compared the existence of a person with the existence of a




club, and claimed that the existence of a club at one time may contain everything that matters as far as the survival of an earlier club goes, even if it is not the same club (1986, pp. 213- 214).

Suppose that in the actual world, wl, a new club, C2, is formed by Agnes, who was impressed by reading an account on a computer of an old club, C1. C2 is just like C1. Sup- pose that although C1's rules were vague about what constitutes its survival or revival in such circumstances, we decide that C2 is C1, and that C2 has what matters in survival or revival for C1.

Suppose that the same events occur in possible world w2, except that the account that Agnes read was in a file, the content of which was randomly generated by a tiny computer glitch. By an incredible coincidence this content is exactly the same as the real account of C1 that Agnes read in w1. If it was not for the glitch, Agnes would have read the real account, and C2 would have been formed. Call the club that results in W2, "C3".

C2 has everything that matters as far as the survival of C1 goes. Does not C3 also have what matters for C1 (even if C3 iS

not C1)? The only difference between C2 and C3 is that there is a causal connection between C1 and C2, but not between C1 and C3. But even with the causal connection, C3 would have been exactly the same as C2. And the computer glitch here is just as trivial as in the previous case, so it cannot be of any great importance in itself, and certainly cannot carry all the importance of what matters in survival here. So we should say that C3 also has what matters to C1. It may or may not be the case that the presence of the causal connection makes it true that C2, but not C3, is numerically identical to C1, but C3 will have what matters in survival to C1 regardless.

If, then, we are to take Parfit's club analogy seriously, we must conclude that it supports sequentialism. A psychological theorist who does not accept that this argument supports sequentialism must explain where the analogy between clubs and people breaks down, and why this disanalogy does not therefore undermine Parfit's "club" argument for the psychological theory.



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1 1. THE "INDISCERNIBLE SWAP" ARGUMENT FOR SEQUENTIALISM

Suppose that the following happens to you. At t1, an evil sci- entist "rewires" your brain (in an almost instantaneous process) so that your brain states match those of a randomly- chosen person. Suppose that these states happen to be qualitatively identical to the states that you had a fraction of a second before the operation at t1, because these states by an incredible coincidence come from your "double" on Twin Earth.

In such a case, your psychological states before t1 are not causally connected to the states that exist after t1 in what used to be your brain. Thus, the psychological theory entails that you do not exist any more, and that the new person who exists after t1 does not have what matters in survival for you. Does not it seem futile, though, to insist that this person does not have what matters in survival for you? He is exactly the same as you would have been if the "overwriting" had not occurred. Could having a causal connection really be all that important to you in such a case? Suppose this had really happened last week - would it really worry you?

Kolak and Martin have also argued in a similar way, with their "Random Match Example" (1987, pp. 341-342). They suppose that ten years ago, your body could have instanta- neously gone out of existence (say, by some amazing quantum fluctuation), while at the same time, by an incredible coincidence, molecules came together randomly in such a way that they constituted a body qualitatively identical to yours, in the exact spot where your body just disappeared (p. 341). Would the knowledge that this had happened make you think that you have only existed since that causal breach? Would you think that the person who existed after the breach did not have what matters in survival for the person who existed before the breach? Kolak and Martin say "when we contemplate such possibilities... [we find that] such breaches would not disturb us if they occurred" (p. 342). This reaction, they claim, is evidence that identity is preserved in such cases.




12. A SEQUENTIALIST SOLUTION TO A BRANCHING PROBLEM

Here is another argument for sequentialism that involves what Parfit calls a "branch-line" case. Suppose that A steps into the teleporter. At to A's states are copied. The information is sent off, and at t1 the receiver creates Replica. Suppose, though, that the machine malfunctions slightly and fails to destroy the body in the transmitter straight after the copying process, but de- stroys it a few minutes after Replica is created, at t2. This means that A went out of existence at tl, because at t, A branched into Replica and someone else, B, who existed in A's old body from t1 until t2, at which point he was killed.4 Suppose that you are B, and it is just before t1 when you are about to die.

Does Replica have what matters in survival for B after B's death at t2? Parfit thinks he does (pp. 287-289). But this cannot be the case, given Parfit's psychological theory. What matters in survival, according to this theory, is psychological connectedness and/or continuity, but Replica is not causally connected to B, so Replica cannot be psychologically connected or continuous with B. Hence Replica cannot have what matters in survival for B, given the psychological theory.

Parfit appeals to what he takes to be the fact that while Replica is not now psychologically continuous with B, Replica was continuous with B at an earlier point in time, before the branching at tl. But here Parfit is assuming that B existed before t1. However this assumption is false - B only came into existence at tl. B is numerically distinct from the person A who existed before the branching at t1, and so this move is illegitimate.

Sequentialism, on the other hand, provides a simple solution to this problem. Replica is not connected or continuous with B, but Replica is to a very large degree sequential with B. Thus, Replica contains what matters in survival for B, according to sequentialism.

13. OLD TAPES OF YOURSELF

Sequentialism also allows that you would have what matters in survival if you had, a few months ago, copied your entire



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psychological state at that time and stored it away on tape, and left instructions with friends to create a Replica out of this information if you were killed - and you were killed at tl, and a Replica created. Call this replica, "Taped Replica". Consider yourself just before tl. Will Taped Replica have what matters in survival for you? On standard versions of the psychological theory, the answer must be no, as Taped Replica is not causally connected - and hence not R-related - to you at t1. (Standard versions of the theory, it should be remembered, consider personal identity to be a relation that holds between persons at times). Sequentialism, on the other hand, will allow that Taped Replica has what matters in survival for you. (However, a very old recording of yourself made, say, 40 years ago, might have none of what matters in survival for you, because it is nothing like you are now.)

A standard psychological theorist might try to get around this failing by modifying her theory, and saying that what can matter in survival to you at t1 is that after your death there exists a person who is R-related to a person at an earlier time, to, and that you at t1 are also R-related to this person at to. This would allow that Taped Replica has what matters in survival for you, even though Taped Replica is not R-related to you. This follows because Taped Replica is R-related to a person (namely, yourself) at an earlier time, to, who you at t1 (or just before tl) are also R-related to. But this is simply to concede that a causal connection is not necessary, because the "retrospective" cause here is not strictly speaking a cause at all - to have a common cause, or to "spring from the same loins", is good enough.

A further problem for this view is that Parfit says that for any Replica to have what matters for you now, it must be a recently made Replica (1986, p. 289), one which resembles you now, and that a Replica created 40 years ago whose life and personality has diverged considerably since then would not suffice to have what matters for you now. But the standard theory as modified above will entail that this 40-year-old Replica does have what matters for you now, because it is R- related to a person at an earlier time to (i.e. you 40 years ago), and you at t1 are also R-related to this person at to.




This theorist might want to further insist then, that the time gap between t1 and to must not be very long. But all this seems to be to conceding further to sequentialism the point that what is really important is what the Replica is like - what's important is not really anything to with "retrospective" causation, or common causes, or time gaps, but that the Replica is like you. After all, a long time gap could be fine, as long as you have changed little, but a short time gap will not do, if you have changed considerably in the meantime. What counts is how much like you now the Replica is.

14. DOES SWAMPY THE SWAMPMAN HAVE WHAT MATTERS IN SURVIVAL FOR YOU?

Suppose that at t1 you are instantly destroyed. Suppose also that on another planet, a bolt of lightning hits a swamp just after t1, and by an incredible coincidence a person, Swampy, is created by this event, who is just like you were at t1. Sequentialism entails that Swampy has what matters in survival for you.

Those who have been sympathetic to sequentialism so far may feel that it is far more absurd for sequentialism to entail that Swampy has what matters in survival for you than it is for sequentialism to entail than Random does, and that the sequentialist would do well to avoid this implication if she possibly can. However, the sequentialist has no good basis for distinguishing between Swampy and Random, for Replica could have been created out of the exact same materials that Swampy is made of, and at the same time. This means that Swampy and this Replica have a qualitatively - and arguably even a numerically - identical body, and they also have qualitatively (and possibly numerically) identical psychological states. The only difference between such a Replica and Swampy is the causal connection, and this means that Swampy must contain what matters in survival for you if Replica does, because as we have seen, such a difference is a small one.

Sequentialism also entails that if you are suddenly killed at t1, and at t1 there is a "double" of you on Twin Earth, T, who is



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just like you were at t1 except he does not die at t1, then T has what matters in survival for you.

This might seem absurd, but we need to keep in mind that T will have to be exactly like you in every possible way, with the same memories, same beliefs, same personality, same lifestyle, etc. Once we reflect on that, and bear in mind that the chances of this happening are vanishingly small, then, at least in my opinion, it does not seem so absurd after all. At least, it is no more absurd than the view that Replica is you.5

15. AN EXTERNALIST OBJECTION

Here is a possible objection to the sequentialist view from a psychological theorist who accepts externalism about mental states, an objection that is intended to show that a causal connection is necessary. This objector will claim that there is an important difference between Replica and Random. Random, being newly created, is not yet causally connected to anything. Replica, on the other hand, is causally connected to things, through being the causal product of earlier states of myself. Thus, Replica can refer to things, while Random cannot (and the same applies to Swampy). Random's mental states will therefore have internal content, but they will not have external content.6 If externalism is true, then it will follow that Replica has genuine memories of my life, or at least "quasi-memories", but Random will have no memories or quasi-memories at all. Nor will Random have any intentions or quasi-intentions, or any beliefs, and so on, because these states only exist if there is "external content".

The externalist will then claim that no person can have what matters in survival for me if they do not have any beliefs, quasi- memories, intentions, and so on, because it is these sorts of states that the psychological theorist holds are what matters in survival. So Random cannot have what matters in survival for me. Hence, what matters in survival can exist only if there is a causal connection, because without a causal connection there will not exist any beliefs, intentions, etc.




The sequentialist can reply to this objection in the following way. Suppose it is true that Random does not have beliefs, quasi-memories, intentions, etc., whereas Replica does. Call the states that Random has (which have internal content only) "near-beliefs", ''near-intentions'' and "near-quasi-memories" and so on. The question that now arises is, are near-beliefs, near-intentions, etc., as good, or almost as good, as beliefs, intentions, etc.?

Near-beliefs will be almost exactly the same as beliefs, and near-intentions will be almost exactly the same as intentions, and so on. So Random's states will be almost the same as Replica's. In fact, subjectively, they will be qualitatively identical, and Random's behaviour will be exactly the same as Replica's would be. The only difference between Random and Replica in regards to the type of states they will have is that Replica's states will be causally connected to some earlier states (namely mine), whereas Random's will not be. But we have seen that this difference is a minor one, and cannot be taken to be the difference between having all of what matters in survival and none of what matters in survival. So near-beliefs, etc., although they may not be quite the same as beliefs, must be as good, or almost as good, as beliefs, etc. Hence the externalist cannot maintain that Random fails to have what matters in survival for me. A future person who has near-beliefs, etc., is as good as, or almost as good as, a future person who has beliefs, etc. An externalist who insisted that only genuine mental states would do, and that near-mental states were completely inade- quate as far as what matters in survival goes, would be, in effect, rejecting the P2 principle, and so undermining the psychological theory.7

16. COUNTERFACTUAL DEPENDENCE

Consider this objection. In one way of looking at matters, the only difference between worlds w1 and w2 is the tiny glitch. But in another way of looking at matters, there is a much larger difference between w1 and w2, namely that in w1, but not in w2,



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the psychological states of the person created by the teleporter are counterfactually dependent upon my psychological states. For example, in w1, if, instead of having had memories x, y and z, I had had memories x', y' and z', then Replica would also have had memories x', y' and z', rather than x, y and z. If I had had different beliefs, then Replica would also have had the corresponding beliefs. And so on for the other relevant psychological states. But none of this is true of Random. None of his psychological states would have been different if mine had been different. His states are not counterfactually dependent upon mine, as Replica's are. So if I had been different, then Random would not have had what matters in survival for me.

The objector will claim that this shows that there is a significant difference between w1 and w2, a difference we failed to take into account earlier, and this difference is important for what matters in survival. Thus, Random will not have what matters in survival for me, but Replica will.

But why should such counterfactual dependence be important? It can only be important because in almost all possible situations, without there existing a causal connection between me and a future person, that future person will not have the right sort of psychological states (i.e. ones similar to mine). Only by an incredible coincidence would he have such states without there existing any counterfactual dependence of these states upon mine. This means, though, that what is really important is the right sort of states themselves, rather than the counterfactual dependence. The importance of the counterfactual dependence is derivative upon the importance of there existing states of the right type. And there are possible situations where such states can exist in the future without a causal connection.

So such counterfactual dependence is only "virtually" necessary, rather than really necessary, because it is virtually impossible for the right sort of states to exist in the future unless they are counterfactually dependent upon mine. But, as it happens, by an incredible coincidence the right sort of states were produced in w2 without being counterfactually dependent upon my states. So what is important does exist in w2.




So, just as Parfit claimed in his argument for the widest view, what counts is the effect. (Or - to do away with the causal implication of "effect" - what counts is the end result). What we wanted to exist in w2 was a specific body with specific states. And that is what was created, even though it was sheer luck that it happened. Going back to the catapult analogy, it is as though the catapult had failed, but a box of supplies just like the one in the catapult miraculously appeared on the other side of the ravine, while the one in the catapult miraculously disappeared. There is no counterfactual dependence here because the miraculous box would have appeared no matter what was on the catapult. We still got what we wanted, though, even though it was through pure luck. But a lucky success is still a success, just as it was with the unreliable catapult. And an unbelievably lucky success is still a success.

For all practical purposes, then, an appropriate causal connection is needed, but strictly speaking, a causal connection is not a part of what matters in survival. The only acceptable "substitute" for it, though, is an incredible coincidence which results in exactly the same situation occurring as the appropriate causal connection would have produced. Such a coincidence is, of course, almost impossibly rare (and, practically speaking, would never occur), but that does not make it true that a causal connection is necessary.

A similar counter-reply to this objection to sequentialism is as follows. The objector takes counterfactual dependence to be important. However, this counterfactual dependence, being counterfactual, involves what the future person in question would have been like in other possible worlds, that is, in worlds other than w2. But we are concerned with whether a future person has what matters in survival in possible world W2 only. Whether this person (or a counterpart) has what matters in survival in other possible worlds is irrelevant to whether he does in w2.

After all, if we are going to consider other possible worlds, then we could point out that in some possible worlds, Replica (or a counterpart of Replica) could exist, and be causally connected to me, but not have what matters in survival for me



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(because, for example, some of the information was scrambled by the teleporter).8 The objector would not accept that this shows that Replica does not have what matters in survival for me in the actual world. So it is hardly fair for the objector to then say that Random does not have what matters for me in survival in w2 on the grounds that Random (or a counterpart of Random) does not have what matters in survival for me in possible worlds other than w2.

17. OPPONENTS OF SEQUENTIALISM

I have not argued that sequentialism should be accepted. What I have argued is that it should be accepted if the psychological theory is. And there will be, I think, two main types of possible opponents of sequentialism. Opponent 1 accepts the psychological theory, but denies that sequentialism follows from it. Opponent 2 accepts that the psychological theory leads to sequentialism, and holds that this is a reason to reject the psychological theory.

Opponent 1 may argue that sequentialism is absurd, and that this is reason enough for it to be rejected. Although sequentialism is certainly prima facie bizarre and counter-intuitive, I am not convinced that it is absurd, but I shall not argue this here. What I shall point out is that it is not enough for Opponent 1 just to claim or even show that sequentialism is absurd. Even if it is, Opponent 1 must also show that sequentialism does not follow from the basic tenets of the psychological theory. I have argued that it does. If I am right, then if sequentialism is absurd, it follows that the psychological theory is also absurd, and also should be rejected (as Opponent 2 will agree). So Opponent 1 must show that there is a flaw in the sequentialist's reasoning, rather than the (supposed) absurdity being implicit in the foundations of the psychological theory.

It can also be pointed out against Opponent 1 that the arguments for sequentialism are similar to the arguments for the widest view, such as that what matters is the "right effect", not the cause. If the arguments for sequentialism fail, then maybe the arguments for the widest view will fail as well. So




any psychological theorist who accepts the widest view but not sequentialism will need to show that there is a relevant difference between the arguments for sequentialism and the widest view, contrary to what I have argued.

18. CONCLUSION

The sequentialist concludes that the psychological theorist should accept that a causal connection is not necessary to what matters in survival. It is possible that B at t2 can have what matters in survival for A at tl, even though A and B are not causally connected. It is extremely unlikely that a case would ever exist in actuality, but it still remains true that a causal connection is not strictly necessary.

ACKNOWLEDGEMENTS

Thanks to Raymond Martin, Paul Snowdon, Andrew Brennan, Phil Cam, Caroline West, Neil Harpley and Bill Fish for helpful comments.

NOTES

1 See, for example, Martin and Deutscher (1966), Shoemaker (1984, pp. 82-84).

2 See Parfit (1986, p. 220); Shoemaker (1984, pp. 90-91; 1970, esp. section IV).

3 Or even numerically identical psychological states, depending on whether or not the identity of the states is primarily tied to the person. (See Campbell, 2001 for some reflections that have some relevance to this issue.)

4 Some psychological theorists may object that there is no branching here if we accept Nozick's closest continuer theory (1981, Chapter 1). They will say that whereas Replica is only psychologically continuous with A, the person in the transmitter at t2 is both physically and psychologically continuous with A at to, and so this person is A's closest continuer, and so is A. However, this move is only open to those who, like Nozick, accept a hybrid view, which takes physical continuity to also be involved in identity and what matters in survival. It is not open to the psychological theorist.

5 T will not have all that matters to you in other ways, separate from survival - for example, he will not look after your children (although he will



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have children just like yours). But this is not relevant to what matters in survival (that is, what matters in the way that your continued existence is normally supposed to matter), any more than it is relevant to whether or not you continue to exist.

6 I know some philosophers who are tempted by the view that Swampy will not even have internal content - and he will be incapable of doing anything - but this sort of radical externalism raises issues I do not have the space to consider here.

7 If externalism is true, then the sequentialist will have to modify their definition of quasi-connectedness so that it allows that quasi-connectedness relations can hold with near-mental states as well as with genuine mental states.

8 I say more about issues involved in identity across possible worlds in Campbell (2000).

REFERENCES

Campbell, S. (2000): 'Could Your Life Have Been Different?', American Philosophical Quarterly 37(1), 37-50.

Campbell, S. (2001): 'Persons and Substances', Philosophical Studies 104(3), 253-267.

Kolak, D. and Martin, R. (1987): 'Personal Identity and Causality: Becoming Unglued', American Philosophical Quarterly 24, 39-47.

Martin, C.B. and Deutscher, M. (1966): 'Remembering', Philosophical Re- view 75, 61-96.

Nozick, R. (1981): Philosophical Explanations, Oxford: Clarendon. Parfit, D. (1986): Reasons and Persons, Oxford: Clarendon, rev. ed. (first

published 1984). Shoemaker, S. (1970): 'Persons and Their Pasts', American Philosophical

Quarterly 7, 269-285. Shoemaker, S. (1984): 'Personal Identity: A Materialist's Account', in

S. Shoemaker and R. Swinburne, Personal Identity, by Oxford: Blackwell, pp. 69-132.

Department of Philosophy University of Nottingham University Park Nottingham NG7 2RD UK E-mail: scott.campbell@,nottingham.ac.uk



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Is Causation Necessary for What Matters in Survival?