Online research in philosophy

Abstract: Those who endorse the Psychological Continuity Approach (PCA) to analyzing personal identity need to impose a non-branching constraint to get the intuitively correct result that in the case of fission, one person becomes two. With the help of Brueckner's (2005) discussion, it is shown here that the sort of non-branching clause that allows proponents of PCA to provide sufficient conditions for being the same person actually runs contrary to the very spirit of their theory. The problem is first presented in connection with perdurantist versions of PCA. The difficulty is then shown to apply to endurantist versions as well.

Most versions of the psychological-continuity approach to personal identity (PCA) contain a 'non-branching' requirement. Recently, Robert Francescotti has argued that while such versions of PCA handle Parfit's standard fission case well, they deliver the wrong result in the case of an intact human brain. To solve this problem, he says, PCA-adherents need to add a clause that runs contrary to the spirit of their theory. In this response, I argue that Francescotti's counterexample fails. As a result, the revision he suggests is not needed.

This paper re-examines the question of whether quirks of early human foetal development tell against the view (conceptionism) that we are human beings at conception. A zygote is capable of splitting to give rise to identical twins. Since the zygote cannot be identical with either human being it will become, it cannot already be a human being. Parallel concerns can be raised about chimeras in which two embryos fuse. I argue first that there are just two ways of dealing with cases of fission and fusion and both seem to be available to the conceptionist. One is the Replacement View according to which objects cease to exist when they fission or fuse. The other is the Multiple Occupancy View – both twins may be present already in the zygote and both persist in a chimera. So, is the conceptionist position tenable after all? I argue that it is not. A zygote gives rise not only to a human being but also to a placenta – it cannot already be both a human being and a placenta. Neither approach to fission and fusion can help the conceptionist with this problem. But worse is in store. Both fission and fusion can occur before and after the development of the inner cell mass of the blastocyst – the entity which becomes the embryo proper. The idea that we become human beings with the arrival of the inner cell mass leads to bizarre results however we choose to accommodate fission and fusion.

(No abstract is available for this citation).

In his Reasons and Persons, Derek Parfit argues from the possibility of cases of fission and/or fusion of persons that one must reject identity as what matters for personal survival. Instead Parfit concludes that what matters is “psychological connectedness and/or continuity with the right kind of cause,” or what he calls an R-relation. In this paper, I argue that, if one accepts Parfit’s conclusion, one must accept that R-relations are what matter for moral responsibility as well. Unfortunately, it seems that accepting that the R-relation is what matters for both survival and moral responsibility leads to a contradiction. My goal, however, is not merely to point out a problem in Parfit’s account. Instead, I believe that once we understand the basic intuitions which lead to this contradiction, it is clear that there is no fully satisfactory way to account for what matters with respect to survival and moral responsibility.