For 2,000 years, the standard philosophical model of knowledge was that it could be defined as a justified true belief. According to this way of thinking, we can know, for example, that we are human because [1] we believe ourselves to be human; [2] that belief is justified (others treat us as humans, not as dogs); and [3] the belief is true. This definition, which dates to Plato, was challenged by Edmund Gettier in one of the most influential works of philosophy published in the last century – a three page paper that produced two clear examples of justified true beliefs that could not, in fact, be considered knowledge. Gettier's achievement rests on solid foundations provided by his mastery of the critical thinking skill of analysis. By understanding the way in which Plato – and every other epistemologist – had built their arguments, he was able to identify the relationships between the parts, and the assumptions that underpinned then. That precise understanding was what Gettier required to mount a convincing challenge to the theory – one that was bolstered by a reasoning skill that put his counter case pithily, and in a form his colleagues found all but unchallengeable.

This book enriches our understanding of knowledge and Gettier's challenge, stimulating debate on a central epistemological issue.

For 2,000 years, the standard philosophical model of knowledge was that it could be defined as a justified true belief. According to this way of thinking, we can know, for example, that we are human because [1] we believe ourselves to be human; [2] that belief is justified (others treat us as humans, not as dogs); and [3] the belief is true. This definition, which dates to Plato, was challenged by Edmund Gettier in one of the most influential works of philosophy published in the last century – a three page paper that produced two clear examples of justified true beliefs that could not, in fact, be considered knowledge. Gettier's achievement rests on solid foundations provided by his mastery of the critical thinking skill of analysis. By understanding the way in which Plato – and every other epistemologist – had built their arguments, he was able to identify the relationships between the parts, and the assumptions that underpinned then. That precise understanding was what Gettier required to mount a convincing challenge to the theory – one that was bolstered by a reasoning skill that put his counter case pithily, and in a form his colleagues found all but unchallengeable.

Offering a philosophical examination of the concept of luck and its relationship to knowledge, this text demonstrates how a more nuanced understanding of the relationship between knowledge and luck can enable us to see past some of the most intractable disputes in the contemporary theory of knowledge.

The Gettier Problem has shaped most of the fundamental debates in epistemology for more than fifty years. Before Edmund Gettier published his famous 1963 paper, it was generally presumed that knowledge was equivalent to true belief supported by adequate evidence. Gettier presented a powerful challenge to that presumption. This led to the development and refinement of many prominent epistemological theories, for example, defeasibility theories, causal theories, conclusive-reasons theories, tracking theories, epistemic virtue theories, and knowledge-first theories. The debate about the appropriate use of intuition to provide evidence in all areas of philosophy began as a debate about the epistemic status of the 'Gettier intuition'. The differing accounts of epistemic luck are all rooted in responses to the Gettier Problem. The discussions about the role of false beliefs in the production of knowledge are directly traceable to Gettier's paper, as are the debates between fallibilists and infallibilists. Indeed, it is fair to say that providing a satisfactory response to the Gettier Problem has become a litmus test of any adequate account of knowledge even those accounts that hold that the Gettier Problem rests on mistakes of various sorts. This volume presents a collection of essays by twenty-six experts, including some of the most influential philosophers of our time, on the various issues that arise from Gettier's challenge to the analysis of knowledge. Explaining Knowledge sets the agenda for future work on the central problem of epistemology.

With one exception, all of the papers in this volume were originally presented at a conference held in April, 1978, at The Ohio State University. The excep tion is the paper by Wilfrid Sellars, which is a revised version of a paper he originally published in the Journal of Philosophy, 1973. However, the present version of Sellars' paper is so thoroughly changed from its original, that it is now virtually a new paper. None of the other nine papers has been published previously. The bibliography, prepared by Nancy Kelsik, is very extensive and it is tempting to think that it is complete. But I believe that virtual com pleteness is more likely to prove correct. The conference was made possible by grants from the College of Human ities and the Graduate School, Ohio State University, as well as by a grant from the Philosophy Department. On behalf of the contributors, I want to thank these institutions for their support. I also want to thank Marshall Swain and Robert Turnbu~l for early help and encouragement; Bette Hellinger for assistance in setting up the confer ence; and Mary Raines and Virginia Foster for considerable aid in the pre paration of papers and many other conference matters. The friendly advice of the late James Cornman was also importantly helpful. April,1979 GEORGE S. PAPPAS ix INTRODUCTION The papers in this volume deal in different ways with the related issues of epistemic justification or warrant, and the analysis of factual knowledge.

Develops a new logic paradigm which emphasizes evidence tracking, including theory, connections to other fields, and sample applications.