Ever since Plato it has been thought that one has knowledge only if one has belief, one's belief hits the mark of truth, and does so with adequate justification. The debate between Laurence BonJour and Ernest Sosa primarily concerns the nature and conditions of such epistemic justification, and its place in our understanding of human knowledge.

BonJour defends a traditional, internalist epistemology, according to which epistemic justification derives from the subject's taking what is given to his conscious awareness, and accepting claims or steps of reasoning on an a priori basis. Sosa defends an externalist virtue epistemology. He rejects the sort of internalist foundationalism favored by BonJour, while agreeing to put aside questions of knowledge and its conditions, in order to focus on epistemic, rational, justification. He accepts that a belief's having a reliable source is not enough to render it thus justified. The two comprehensive positions that are the antagonists in this debate represent syntheses of the main views that have been proposed with regard to the nature of epistemic justification. The confrontation between them throws light on significant and interacting aspects of the subject.

Review

"It is a wonderful treat for anyone interested in epistemology to find an exchange on the most basic epistemological problems between two such distinguished practicioners as BonJour and Sosa. This debate is conducted with the mastery and sophistication we have come to expect from them. Epistemic Justification is particularly valuable because not only does each author present and defend a position, but each responds at considerable length to the other." -- William P. Alston, Syracuse University

"BonJour and Sosa offer a penetrating exploration of the internalism/externalism controversy in epistemology. While they vigorously and effectively argue for quite different conclusions, the ability of both philosophers to clearly, fairly, and sympathetically evaluate alternative views results in an outstanding philosophical debate that contributes greatly to our understanding of some of the most fundamental issues in epistemology." -- Richard Fumerton, University of Iowa

"This format, and the eminence of each author, makes the book a valuable addition to the field for practitioners, but also potentially useful as an introduction to many of the most basic problem of contemporary epistemology." -- Choice

Laurence BonJour is Professor of Philosophy at the University of Washington, where he teaches epistemology, history of modern philosophy, metaphysics, philosophy of law, and political philosophy. He is the author of three books: The Structure of Empirical Knowledge (1985), In Defense of Pure Reason (1998), and Epistemology: Classic Problems and Contemporary Responses (2002).

Ernest Sosa is Professor of Philosophy at Brown University and Distinguished Visiting Professor at Rutgers University every spring term. He has written widely on epistemology and is author of Knowledge in Perspective (1991). Sosa and His Critics, edited by John Greco, is forthcoming in the Blackwell series, Philosophers and Their Critics.