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. (shrink)

A common reaction to functional diversity is to group entities into clusters that are functionally similar. I argue here that people are diverse with respect to reasoning-related processes, and that these processes satisfy the basic requirements for evolving entities: they are heritable, mutable, and subject to selective pressures. I propose a metric to quantify functional difference and show how this can be used to place psychological processes into a structure akin to a phylogenetic or evolutionary tree. Three species concepts are (...) repurposed from biology and used to understand relationships in that tree. (shrink)