The Argument for Subject-Body Dualism from Transtemporal Identity

In recent papers, Martine Nida-Rümelin (NR) has argued for a position she calls subject-body dualism on the basis of three distinct arguments. One is based on reflection on the emergence of phenomenal consciousness (Nida-Rümelin 2010b). One is based on reflection on our treatment of conscious subjects as active (Nida-Rümelin 2006). One is based on reflection on intelligible possibilities of transtemporal identity in fission cases drawn from the literature on person-identity over time (Nida-Rümelin 2010a). In this paper, I am concerned only with last of these arguments. Arguments from reflections on personal identity to a form of subject-body dualism have been around for a while. For example, (Swinburne 1984, 1986) has focused on the implications of duplication cases as well as the possibility of survival of the destruction of the body. More recently (Lowe 2010a, sec. 1.4) has argued for a form of subject-body dualism on the grounds of a difference between the identity conditions for persons and bodies. What I take to be distinctive about NR’s argument is the focus on there being a factual difference between the claims that the original subject is one, or the other, of the two resultant subjects in fission cases. It is the role of this claim in her argument that will be my central focus. I argue that on each of the three most plausible interpretations of this assumption the argument fails.