Models of the self: Editors' introduction

There is a long history of inquiry about human nature and the nature of the self. It stretches from the ancient tradition of Socratic self-knowledge in the context of ethical life to contemporary discussions of brain function in cognitive science. At the beginning of the modern era, Descartes was led to the conclusion that self-knowledge provided the single Archimedean point for all knowledge. His thesis that self is a single, simple, continuing, and unproblematically accessible mental substance resonated with common sense, and quickly came to dominate European thought. Against this background, the philosophical problem pertaining to self-identity arises and continues to define much of the contemporary discussion. Notably, it arises in the context of the first sustained discussion of consciousness in the philosophical literature, and at a precisely definable point in space, time, and text, in the pages of Locke's Essay Concerning Human Understanding. Locke defines it as the problem of personal identity. Briefly stated, the problem involves finding criteria that can account for the unity of the self in conscious experience over time. Locke's solution -- that consciousness maintains its identity over time only so far as memory extends to encompass past experience -- almost immediately produced philosophical controversies that have not abated to this day