When Do We Say 'He Is No Longer Himself'? A Pluralist, Functional Theory of Personal Continuity

The phrase “he is no longer himself” occurs in clinical, familial, and legal contexts with an apparent unity of meaning that does not survive analysis. This paper argues that this unity is illusory: the question of when a person stops being themselves admits no single answer because it presupposes a single definition of “self,” whereas the history of the philosophy of personal identity has produced at least five — not so much five competing answers to one fixed question, as five different ways of specifying what that question is actually asking, with verdicts often incompatible on the same cases. The thesis defended here is not relativist: a theory is constructed in which this pluralism can be rendered non-arbitrary by constraining the criterion relevant in a given context to the logical type of the practical act that the judgment must support — a clinical end-of-life decision, an attribution of responsibility, the processing of grief, an assessment of prospective capacity, the determination of death. The constraint thus proposed is an argumentative method for assigning criteria to domains, not an empirical description of how criteria are in fact used — a distinction the paper states explicitly, together with its own structural limits.