Locke's Place‐Time‐Kind Principle

Abstract

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 (2.27.1). 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 placetime-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.

Locke on individuation and identity

“…2 There is some debate on the notion of kind at work here. For an overview, see Gordon-Roth (2015). 3 As Locke wrote later in his Second Reply to Stillingfleet, the principle of individuation 'is the same in all the several species of creatures'.…”

Locke on Individuation and Kinds

“…For those interested in this wider debate, seeGordon-Roth (2015).19 What follows in this section is a rehearsal of the case put forward by DanKaufman (2007). I take it that he is the most forceful defender of this view.…”

“…According to this reading, then, when understood in the relevant sense, a compounded substance and a simple substance can be in the same place at the same time, even should the two substances in question be material. For example, an oak tree is a compounded substance, in the relevant sense, whereas a mass of 5 For an excellent discussion of these three main approaches as well as the main problems associated with them, see Jessica Gordon-Roth (2015). In this brief discussion here, I rely heavily on that paper.…”