This volume features more than fifteen essays written in honor of Peter D. Klein. It explores the work and legacy of this prominent philosopher, who has had and continues to have a tremendous influence in the development of epistemology. The essays reflect the breadth and depth of Klein's work. They engage directly with his views and with the views of his interlocutors. In addition, a comprehensive introduction discusses the overall impact of Klein's philosophical work. It also explains how each of the essays in the book fits within that legacy. Coverage includes such topics as a knowledge-first account of defeasible reasoning, felicitous falsehoods, the possibility of foundationalist justification, the many formal faces of defeat, radical scepticism, and more. Overall, the book provides readers with an overview of Klein's contributions to epistemology, his importance to twentieth and twenty-first-century philosophy, and a survey of his philosophical ideas and accomplishments. It's not only a celebration of the work of an important philosopher. It also offers readers an insightful journey into the nature of knowledge, scepticism, and justification.