Locke’s account of personal identity has been highly influential because of its emphasis on a psychological criterion. The same consciousness is required for being the same person. It is not so clear, however, exactly what Locke meant by ‘consciousness’ or by ‘having the same consciousness’. Interpretations vary: consciousness is seen as identical to memory, as identical to a first personal appropriation of mental states, and as identical to a first personal distinctive experience of the qualitative features of one’s own thinking. (...) There is wide agreement, however, that Locke’s theory of personal identity is meant to complement his moral and theological commitments to a system of divine punishment and reward in an afterlife. But these commitments seem to require also a metaphysical criterion, and Locke is insistent that it cannot be substance. The difficulty reconciling the psychological and metaphysical requirements of the theory has led, at worst, to charges of incoherence and, at best, to a slew of interpretations, none of which is widely accepted. (shrink)

John Locke discusses the notions of identity and diversity in Book 2, Chapter 27 of An Essay Concerning Human Understanding. At the beginning of this much-discussed chapter, Locke posits the place-time-kind principle. According to this principle, no two things of the same kind can be in the same place at the same time . Just what Locke means by this is unclear, however. So too is whether this principle causes problems for Locke, and whether these problems can be resolved. This (...) is significant because the place-time-kind principle is foundational to Locke's discussion of identity. Moreover, the place-time-kind principle stands at the center of a number of lively and long-standing debates in Locke scholarship. These include the debates over the ontological status of Lockean persons, and whether Locke is a relative identity theorist, to name just two. In this paper, I offer a survey of how Locke's place-time-kind principle has been interpreted in the secondary literature. The aim of this taxonomy is to clarify where the differences between competing interpretations lie, and additionally show just how challenging it is to determine which reading is best. (shrink)