In This Article Expand or collapse the "in this article" section John Locke: Identity, Persons, and Personal Identity

  • Introduction
  • Relevant Works by Locke
  • Monographs
  • Locke’s Account of Identity
  • Locke on Substance, Mode, and Body
  • Locke on Persons, Moral Agents, Accountability, Action Appropriation, Reward and Punishment
  • Locke on Personal Identity, Consciousness, and Memory
  • Theological Context
  • Common Objections: Circularity, Transitivity, “Fatal Error”
  • Responses by Locke’s Contemporaries and Early Critics
  • Neo-Lockean Theories and Other Present-Day Approaches

Philosophy John Locke: Identity, Persons, and Personal Identity
Ruth Boeker
  • LAST REVIEWED: 10 November 2022
  • LAST MODIFIED: 25 June 2013
  • DOI: 10.1093/obo/9780195396577-0056


John Locke offered a very rich and influential account of persons and personal identity in “Of Identity and Diversity,” which is chapter 27 of Book 2 of his An Essay concerning Human Understanding. He added it to the second edition in 1694 upon the recommendation of his friend William Molyneux. Locke’s theory was soon after its publication discussed by his contemporaries and has influenced many present-day discussions of personal identity. Distinctive about Locke’s theory is that he argues that the notion of a person is to be distinguished from that of a human organism, or “man” to use Locke’s term, and that of a substance. By distinguishing the notion of a person from the more traditional notions of a human organism and a substance, Locke is able to address moral questions of accountability without having to take a stance on the question of whether the underlying ontological constitution of a person is material or immaterial. The chapter can be divided into two parts: in the first he outlines his general account of identity, and in the second he applies his general account of identity to persons and personal identity. The discussion of Locke’s general account of identity in the secondary literature has focused on whether Locke’s account of identity can be regarded as a version of the thesis that identity is relative and on how Locke understands modes and substances in chapter 27. The secondary literature on Locke’s account of persons and personal identity often focuses on how Locke’s claim that personal identity consists in sameness of consciousness is to be understood. However, some interpreters also draw attention to the importance of the moral and legal dimension which Locke makes explicit in his claim that “person” is a forensic term (II.xxvii.26). Moreover, some scholars have argued that Locke’s theory is to be understood in its religious context. The objections which have repeatedly been raised against Locke include the problem of circularity and the problem of transitivity; Locke’s reference to “fatal error” in II.xxvii.13 has also been regarded as a serious problem for his view. In the 20th century, psychological accounts of personal identity were often called neo-Lockean theories. It is controversial whether neo-Lockean theories differ from Locke’s own theory, and it can be asked whether the moral and religious dimension of Locke’s theory constitutes an important difference.

Relevant Works by Locke

The most important source for understanding Locke’s account of identity, persons, and personal identity is Locke 2008. (References to the Essay are given by Book, chapter, and section; e.g., II.xxvii.9.) Locke offers his account of identity, persons, and personal identity in II.xxvii. Locke’s journal entries from 20 February 1682, reprinted in Locke 1936 and Locke 1683, document his early thoughts on the topic. Other particularly relevant chapters include “Of Power” (II.xxi), which he revised at the time he wrote II.xxvii; his chapters on modes, substances, and relations (II.xxii–xxiv, xxviii); and his chapter on general terms (III.iii). Among Locke’s other writings, his correspondence with Molyneux (Locke 1976–1989, Volumes 4 and 5) provides helpful insight into the composition of II.xxvii. Additionally, some parts of Locke’s correspondence with Edward Stillingfleet help to clarify Locke’s views (Locke 1824, Volume 3). Helpful background is further provided by Locke 2002, Locke 1997, and Locke 1988, especially the chapter “Of Property” (Locke 1988, II.v).

  • Locke, John. Identity of Persons. Bodleian Library MS Locke f. 7, 5 June 1683.

    Locke’s first note concerning personal identity. Not as fully developed as his later theory, but Locke already rejects the view that personal identity consists in sameness of material particles or “corporeal spirits” and claims that personal identity consists in memory and knowledge of one’s past.

  • Locke, John. The Works of John Locke. 12th ed. 9 vols. London: Rivington, 1824.

    Contains Locke’s major works, including posthumously published writings and letters. Volume 3 presents Locke’s letters to Stillingfleet.

  • Locke, John. An Early Draft of Locke’s Essay: Together with Excerpts from His Journals. Edited by R. I. Aaron and Jocelyn Gibb. Oxford: Clarendon, 1936.

    Contains Draft A of Locke’s Essay, which was written in 1671, and excerpts from Locke’s journals that illuminate Locke’s arguments in the Essay. Locke’s journal entry from 20 February 1682 concerns immortality and provides relevant background to his account of personal identity.

  • Locke, John. An Essay Concerning Human Understanding. Edited by Peter H. Nidditch. Oxford: Clarendon, 2008.

    Critical edition, based on the fourth edition (1700; originally published in 1690, second edition 1694). Best edition for students and scholars. The text is unmodernized and includes Locke’s own index. The chapter “Of Identity and Diversity” (II.xxvii, originally published in 1694) is reprinted in John Perry, ed., Personal Identity (University of California Press, 2008).

  • Locke, John. Two Treatises of Government. Edited by Peter Laslett. Cambridge, UK: Cambridge University Press, 1988.

    DOI: 10.1017/CBO9780511810268

    Originally published anonymously in 1690. This edition is prepared for students and contains a detailed introduction, helpful annotations to the text, suggested readings, an extensive bibliography, and an index.

  • Locke, John. The Correspondence of John Locke. 8 vols. Edited by E. S. De Beer. Oxford: Clarendon, 1976–1989.

    Critical edition of Locke’s correspondence. Locke’s correspondence with Molyneux can be found in Volumes 4 and 5 and is reprinted in Mark Goldie, ed., John Locke: Selected Correspondence (Oxford University Press, 2002).

  • Locke, John. Political Essays. Edited by Mark Goldie. Cambridge, UK: Cambridge University Press, 1997.

    A helpful collection which makes easily accessible major and minor essays by Locke focused on political, moral, and religious themes. Locke did not write a systematic work on morality, and the essays included in this collection provide good insight into his thinking on the subject. Contains an introduction, bibliography, and index.

  • Locke, John. Writings on Religion. Edited by Victor Nuovo. Oxford: Clarendon, 2002.

    Offers a good selection of Locke’s writings on religion, prepared for students and scholars. Nuovo’s helpful introduction outlines Locke’s deep interest in religion and theology and suggests that understanding Locke’s works in the context of his religious writings helps one to realize how many of Locke’s works bear upon his religious work.

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