John Locke accepts that every perception gives me immediate and intuitive knowledge of my own existence. However, this knowledge is limited to the present moment when I have the perception. If I want to understand the necessary and sufficient conditions of my continued existence over time, Locke argues that it is important to clarify what ‘I’ refers to. While we often do not distinguish the concept of a person from that of a human being in ordinary language, Locke emphasizes that (...) this distinction is important if we want to engage with questions of identity over time. According to Locke, persons are thinking intelligent beings who can consider themselves as extended into the past and future and who are concerned for their happiness and accountable for their actions. Moreover, for Locke a self is a person, considered from a first-personal point of view. I show that the concept of self that he develops in the context of his discussion of persons and personal identity is richer and more complex than the I-concept that he invokes in his version of the cogito. I further argue that Locke’s moral and religious views explain why he emphasizes the need for a conceptual distinction between persons and human beings. In the final section I turn to the reception of Locke’s view by some of his early critics and defenders, including Elizabeth Berkeley Burnet, an anonymous author, and Catharine Trotter Cockburn. (shrink)