Oxford Bibliographies in Philosophy (2013)
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.