The indeterminacy of identity: A reply to Brueckner

Abstract

Personal identity is not the primary concern in survival; instead, psychological continuity and connectedness, or Relation R, constitute what matters. In cases of fission or “division,” where one individual is psychologically continuous with two future persons, identity fails to hold because identity is a strictly one-one relation, while the psychological features of survival can take a one-many form. This structural divergence demonstrates that numerical identity is not the essential component of what matters in survival. In such branching scenarios, questions of identity are “empty” and indeterminate. While describing the original person as being neither of the resulting individuals may be the most convenient or least arbitrary conceptual refinement, this remains a matter of linguistic description rather than the discovery of a determinate metaphysical fact. A reductionist account of personhood precludes the existence of a “further fact”—such as a Cartesian Ego—that would necessitate a determinate answer in every possible case, including those within a spectrum of physical and psychological change. Consequently, the psychological criterion for identity requires a non-branching clause to maintain consistency, yet the resulting indeterminacy of identity in problem cases does not diminish the significance of the psychological relations that actually constitute survival. – AI-generated abstract.