This collection contains three kinds of papers: mainstream, formal, and programmatic. The mainstream papers use tools like conceptual analysis and historical scholarship to illuminate the nature and extent of our knowledge and justified belief. The formal papers bring tools like modal logic and probability theory to bear on these same topics and related topics like proper reasoning. The programmatic papers outline new approaches to epistemological research. All the papers appear here for the first time. As usual for this sort of volume, the quality varies with the best papers being quite good.