Self-Concern: an experiential approach to what matters in survival

by Raymond Martin

David Mackie

Your brain is divided, and the two halves are transplanted into two new bodies, by a process that ensures that each of the two resulting people is psychologically continuous with you. The rest of your body is destroyed. Most philosophers agree that neither of the two resulting people is identical with—the same person as—you, and that you have now ceased to exist. But does it follow that this procedure is as bad, for you, as ordinary death? “Revolutionaries” about “what matters in survival” answer No: because your mental life flows on, the procedure is about as good, for you, as ordinary survival. Hence “fission cases” of this kind, they say, support the conclusion that strict personal identity is not what matters in survival.

Some philosophers have claimed that this view is obviously mistaken. To be sure, they say, there would be advantages in fission: for example, the twin “products” of my fission could write my book much faster than I can on my own; but there would clearly also be disadvantages: they might fight for the affections of the woman I love, and they would have to share the limited resources of what was hitherto a single person’s life. This, however, is to misunderstand the revolutionaries’ claim. They need not deny that fission might have undesirable consequences. For their claim concerns only what has been called the “prudential” sense of the phrase “what matters”: it is only the claim that one can rationally “identify” with each fission product, and “anticipate” having his experiences, in the way that, in normal life, one anticipates only one’s own future experiences.

Martin’s book is a valuable contribution to the literature on this subject especially for its emphasis on these notions of identification and anticipation. His criticisms of those neo-conservatives who have underestimated the relevance of anticipation, and of those who have resorted to the plainly question-begging assertion that identity has special prudential importance, are convincing. And in the more original sections of the book he presents subtle discussions of the phenomenology of identification and anticipation together with an interesting, if speculative, account of the psychological phenomena underlying our ability to identify with, and anticipate having the experiences of, another person.

Martin is keen to distance himself from earlier discussions of this subject. Both revolutionaries and neo-conservatives, he claims, have set their sights too high in trying to establish excessively strong normative theses—either that a preference for identity is irrational, or that it is rationally required. Martin, by contrast, aims to restrict himself to the “descriptive” question what rational egoistic concerns people actually have. Still, his own conclusions will please the revolutionaries he criticizes far more than the neo-conservatives. In Martin’s favourite case of “fission rejuvenation”, the lives of the two fission products do not overlap, as they do in the standard version of the case; instead, one of these people is put into cold storage, only to be reawakened when the other dies. According to revolutionaries, undergoing fission rejuvenation is the next best thing to doubling your lifespan. And Martin’s own claim that this variant on the standard case is invulnerable to neo-conservative challenges in fact aligns him firmly with the revolutionaries. For if a preference for (non-identity-preserving) fission rejuvenation over ordinary survival is, as Martin claims, rational, then the neo-conservatives, who deny this, must be wrong.

Doubts must remain about some of Martin’s assertions about what people may rationally prefer. In particular, the unfortunate thesis of chapter 4, that it can be rational to want to cease to exist and simultaneously become someone else, is hard to accept, unless Martin can explain how it can be rational to desire a supposed outcome that is logically incoherent as described (for if I genuinely become someone else, I surely don’t cease to exist). Nonetheless, many of his arguments (notably his careful examination of objections to the possibility of rationally anticipating having another person’s experiences in chapter 2, and his development of the fission rejuvenation case in chapter 3) put the ball firmly back in the neo-conservatives’ court, and it is to be hoped that these arguments will be given due consideration in subsequent discussions of this intriguing subject.