We’re pleased to see that a new article on Locke has been added to the Stanford Encyclopedia of Philosophy: “Locke on Personal Identity” by Jessica Gordon-Roth (Minn). Gordon-Roth’s article is exceptionally well-structured and seems like it will be an immensely valuable resource for students, generalists, contemporary metaphysicians, and scholars. She begins by laying out “The Basics” of Locke’s position. First, she describes Locke’s background presuppositions: the fundamental features of identity, the place-time-kind principle, the recognition that persistence conditions vary depending on the type of thing being considered. This leads her to a discussion of Locke’s characterization of persons as “the kind of entity that can think self reflectively and think of itself as persisting over time” and as moral agents. This is what led Locke to argue that “the diachronic identity of persons consists in sameness of consciousness.” Gordon-Roth then discusses all the “imaginary cases” (i.e. thought experiments) that Locke uses to articulate, explain, and defend his conception of personal identity (the prince and the cobbler; waking and sleeping Socrates; the transference of consciousness between thinking substances; Day-and-Night-Man) along with Locke’s questioning of the substantial nature of souls. Taking all of these passages together, Gordon-Roth sees Locke as “carving out a new conceptual space” for thinking about persons and personal identity.

Next Gordon-Roth presents the central interpretative issues Locke’s texts leave us with. She flags the debate between scholars who read Locke as making essentially epistemological claims about what we can know about persons vs. those who read Locke as making metaphysical claims about what persons are and what personal identity consists in. She flags the debate between those who read what Locke is doing with regard to personal identity as coherent with his empiricist approach  in the Essay (the “historical, plain method)versus those who find it anomalous. She flags the debates between scholars who attribute a relativist account of identity to Locke versus those who reject such characterizations. She flags the debates between modal interpretations of Locke’s account of persons versus substance readings of Locke on persons. And she flags the debates between strict memory theorists accounts of Locke’s “sameness of consciousness” versus appropriation accounts. She also flags the difficulties with accounting for what Locke meant by “consciousness” itself. And finally, she flags the debates regarding what Locke thinks gives rise to consciousness.

Next, Gordon-Roth provides us with a very interesting presentation of the early reception of Locke’s account of persons. She presents Joseph Butler’s rebuttals, Thomas Reid’s objections, and Catharine Trotter Cockburn’s defense of Locke’s account. She also presents Edmund Law’s influential late eighteenth-century defense of Locke’s account. Gordon-Roth also looks at how philosophers have used Locke’s account to develop theories that go well beyond what Locke was or would have been comfortable with. From Anthony Collins’ materialist account of persons to David Hume’s fictionalism with regard to persons and personal identity. She also mentions William Hazlitt’s 1805 attempt to undercut the attribution of personal identity to future selves as developing Locke’s ideas in non-Lockean ways.

Gordon-Roth ends her article by exploring the ways contemporary practitioners have made use of Locke’s ideas. She considers how psychological continuity theorists (Perry, Lewis, Shoemaker, and Parfit) as well as opponents to such views (Schechtman) have leveraged Locke’s ideas to support their positions. She considers how animalist accounts of person and personal identity (Olson) have done the same. She looks at how others situate their non-Lockean theories against Locke (Blatti and Snowdon, Adeofe, and Wilkes).

Gordon-Roth’s new contribution to the Stanford Encyclopedia of Philosophy is a rich and rewarding text, which we encourage all Lockeans to check out. It is an excellent addition to the SEP generally and and clearly worthy of standing alongside the other excellent SEP articles devoted to Locke (“John Locke” by William Uzgalis; “Locke on Moral Philosophy” by Patricia Sheridan; “Locke on Freedom” by Samuel Rickless; “Locke on Real Essence” by Jan-Erik Jones; “Locke’s Philosophy of Science” by Hylarie Kochiras; and “Locke’s Political Philosophy” by Alex Tuckness.