Hostname: page-component-77c78cf97d-d2fvj Total loading time: 0 Render date: 2026-04-24T07:43:54.101Z Has data issue: false hasContentIssue false
  • English
  • Français

The Psychological Approach to Personal Identity: Non-Branching and the Individuation of Person Stages

Published online by Cambridge University Press:  27 April 2009

Anthony Brueckner  and
Christopher T. Buford
Anthony Brueckner
Affiliation:
University of California, Santa Barbara
Christopher T. Buford
Affiliation:
University of Akron
Get access Rights & Permissions [Opens in a new window]

Abstract

We begin by discussing some logical constraints on the psychological approach to personal identity. We consider a problem for the psychological approach that arises in fission cases. The problem engenders the need for a non-branching clause in a psychological account of the co-personality relation. We look at some difficulties in formulating such a clause. We end by rejecting a recently proposed formulation of non-branching. Our criticism of the formulation raises some interesting questions about the individuation of person stages.

Information

Type
Articles
Information
Dialogue: Canadian Philosophical Review / Revue canadienne de philosophie , Volume 47 , Issue 2 , Spring 2008 , pp. 377 - 386
Copyright
Copyright © Canadian Philosophical Association 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

References

Notes

1 See Parfit, Derek, Reasons and Persons (Oxford: Clarendon Press, 1984), p. 262.Google Scholar

2 See Lewis, David, “Survival and Identity,” in The Identities of Persons, edited by Rorty, A. O. (Berkeley, CA: University of California Press, 1976), pp. 17–40, esp. pp. 24–25.Google Scholar

3 For a rather confusing discussion of what counts as a sufficient number, see Parfit, , Reasons and Persons, p. 206.Google Scholar

4 Parfit discusses three candidates for what counts as the right kind of cause: the normal cause, any reliable cause, and any cause (ibid., p. 207). On the latter two possibilities, a pre-beaming-up stage of Captain Kirk will be C-related to a post-beaming-up stage, as in a Parfitian Simple Teletransportation case. It is worth noting that some direct psychological connections between stages have causation “built into” them, such as memory connections.

5 In general, the ancestral of a relation is guaranteed to be transitive.

6 If x is psychologically continuous with y, then there is a chain of strong connectedness linking x to y through 0 or more stages. For example, it might be that xCz and zCy. Since C is symmetric, we have yCz and zCx. Thus, there is a C-chain linking y to x. Thus, y is R-related to x.

7 See Grice, Paul's “Personal Identity,” in Personal Identity, edited by Perry, J. (Berkeley, CA: University of California Press, 1975), pp. 73–95.Google Scholar

8 See Parfit, , Reasons and Persons, p. 254.Google Scholar

9 Parfit would deny that BRC (see ibid., p. 302). But, as we have seen, any reasonable account of the R-relation must have R come out as symmetric, since, quite obviously, I is symmetric. Once it is made clear that R is symmetric, it will follow that BRC, just as in the famous Grice case discussed above in the text.

10 See Lewis, , “Survival and Identity,” p. 27.Google Scholar

11 See Parfit, , Reasons and Persons, p. 262.Google Scholar

12 For a discussion of a number of failed attempts to formulate a non-circular non-branching clause, see Brueckner, Anthony's “Branching in the Psychological Approach to Personal Identity” (Analysis, 65 [2005]: 294–301).CrossRefGoogle Scholar

13 For Formulation (5), see ibid., p. 298. Noonan, Harold's article is “Nonbranching and Circularity—Reply to Brueckner” (Analysis, 66 [2006]: 163–77).CrossRefGoogle Scholar

14 See Noonan, , “Non-branching and Circularity—Reply to Brueckner,” p. 166.Google Scholar

15 See ibid.

16 See Parfit, , Reasons and PersonsGoogle Scholar, §87.

17 There are several other analyses of who is who during the disconnection that are even more implausible. We leave this to the reader to work through.

18 See Noonan, , “Non-branching and Circularity—Reply to Brueckner,” p. 166.Google Scholar

19 According to (AX), it cannot be that two simultaneous person stages are stages of a single person. We saw earlier that, according to Lewis, one person stage can be a stage of two simultaneously existing persons.

20 If time travel is logically possible, then this leads to a further problem for (5). If President Bush were to travel backward in time and observe his fourth birthday party, then two co-personal stages of George W. Bush would exist simultaneously: a Presidential stage and a kiddy stage. Thanks here to an anonymous referee.

21 It is worth noting that Parfit's famous argument that the R-relation, not the I-relation, is what rationally ought to matter to us requires an account of the I-relation according to which ~(AIB) and ~(AIC) in fission cases, though we do have ARB and ARC. The argument is as follows. In a case in which the right hemisphere is damaged and never transplanted, A ought to be very pleased nevertheless at the prospect of the successful transplant of the left hemisphere. Call this case My Bungled Division (MBD). Since the relation between A and B in MBD is exactly similar to the relation between A and B in My Division, A ought to be equally pleased about the prospect of B's existence in My Division. We have ARB in My Division, but, given a violation of non-branching, we have ~(AIB). So R, not I, is what matters. Thus, Parfit's famous argument about what matters requires the availability of a successful formulation of a non-branching clause.