Abstract
Personal indexicals are often taken to refer to the agent of an expression’s context, but deviant uses (e.g. ‘I’m parked out back’) complicate matters. I argue that personal indexicals refer to the extended self of the agent, where the extended self is a mereological chimera incorporating whatever determines our behavioral capacities. To ascertain the persistence conditions of personal identity, I propose a method for selecting a level of description and a set of functional properties at that level that remain constant over a lifetime. I argue for functional constancy, and against continuity, as the central determinant of diachronic identity.