Probably the most divisive philosopher of the 20th century, Martin Heidegger is considered by some to be the greatest charlatan ever to claim the title of philosopher, by some as an apologist for Nazism, and by others as an acknowledged leader and central figure to many philosophers. Michael Inwood's lucid introduction to Heidegger's thought focuses on his most important work, Being and Time, and its major themes of existence in the world, inauthenticity, guilt, destiny, truth, and the nature of time. These themes are then reassessed in the light of Heidegger's later work, together with the extent of his philosophical importance and influence.