CEFISES Seminar: Vincent Grandjean, “Indeterminate Personal Identity”

Series: OLOFOS

Speaker: Vincent Grandjean (University of Neuchatel)

Title: “Indeterminate Personal Identity”

Abstract

In this paper, I discuss a prominent objection to psychological accounts of personal identity over time: the fission objection. I argue that a specific approach to this objection, involving a type of metaphysical indeterminacy, has been overlooked in previous literature. This approach allows for the preservation of the commonly held belief that psychological continuity serves as the criterion for diachronic personal identity, without separating survival from identity or resorting to multiple-occupancy. Specifically, I suggest that a person before fission is identical to one of the two resulting persons after fission, but it is indeterminate which one. Contrarily to previous claims, this approach does not conflict with classical logic or Tarskian semantics, and aligns with David Wiggins’ ‘Only a and b Principle’, according to which facts about objects other than a and b are irrelevant to whether a is identical to b.