A Companion to Heidegger is a complete guide to the work and thought of Martin Heidegger, one of the most influential philosophers of the twentieth century. The volume opens by focusing on the most important elements of Heidegger's intellectual biography, including his notorious involvement with National Socialism. The book then goes on to provide a systematic and comprehensive exploration of Heidegger's work. The contributions proceed chronologically, starting with discussions of his magnum opus Being and Time, moving on to the period of his 'Kehre' or 'turn', and concluding with his neglected later work. A final section contains key critical responses to Heidegger's philosophy, including consideration of his relation to pragmatism, religion, and ecology. Contributors include many of the leading interpreters of, and commentators on, the work of Heidegger.