A criterion of diachronic identity based on Locke's Principle

The aim of this paper is to derive a perfectly general criterion of identity through time from a suggestion made by Peter F. Strawson almost thirty years ago in an article called 'Entity and Identity' (1976). The reason why the potential of this suggestion has so far remained unrealised is twofold: firstly, the suggestion was never properly developed by Strawson, and secondly, it seemed vulnerable to an objection that he himself raised against it. Consequently, my aim in this paper is to further develop Strawson's suggestion, and to show that the result is not vulnerable to the objection that seemed fatal to its underdeveloped predecessor.