1 Endurance, Psychological Continuity, and the Importance of Personal Identity*

Persons enjoy identity over time. But persons do not have temporal parts. They are not four-dimensional entities “spread out ” in time. Rather, persons last over time by enduring. Or so I say. The main objective of this paper is not to defend the thesis that persons endure over time—although I will say something in defense of it—but instead to highlight an important implication of that thesis. I will show that if persons endure, then it cannot be that personal identity over time should be analyzed in terms of—or is nothing other than—psychological continuity. In other words, I will show that any analysis or reduction of personal identity over time in terms of some kind of psychological continuity entails four-dimensional persons and temporal parts. John Locke was the most important historical defender of the view that personal identity should be understood in terms of psychological continuity. And Locke’s legacy lives on. It is no exaggeration to say that among the analyses of personal identity over time defended today and in the recent past, analyses that make heavy use of psychological continuity have enjoyed almost complete hegemony. Such analyses ar