The Oxford Handbook of Skepticism features twenty-six newly commissioned articles by top figures in the field of skepticism. In the history of philosophical thought, few themes loom as large as skepticism. Skepticism has been the most visible and important part of debates about knowledge. Skepticism, at its most basic, questions our cognitive achievements, challenges our ability to obtain reliable knowledge. It casts doubt on our attempts to seek and understand the truth about everything from ethics, to other minds, religious belief, and even the underlying structure of matter and reality. Since Descartes, the defense of knowledge against skepticism has been one of the primary tasks not just of epistemology but philosophy itself. Part One contains articles explaining important kinds of skeptical reasoning. Part Two focuses on responses to skeptical arguments. Part Three concentrates on important contemporary issues revolving around skepticism.