Heidegger towers above this century as a thinker able to wrest insights from ancient texts (Plato, Heraclitus, and Parmenides) while simultaneously opening distinctively modern perspectives for contemporaries (Sartre, Tillich, and Arendt). With admirable erudition and sophistication, Safranski recounts the evolution of this giant from a cautious Catholic seminarian to a daring explorer of the depths of anxiety and alienation. A different kind of subtlety--more psychological than philosophical--comes into play in the analysis of why Heidegger veered from his quest for truth to serve Adolf Hitler. While refusing to exculpate him for supporting an evil movement, Safranski shows how philosophical reasoning belatedly helped Heidegger distance himself from Nazism, so opening the way to a fruitful postwar investigation of the human place in a technological world. As the well-told story of a life that combined, as few have, a heroic rage for truth with a tragic vulnerability to error, this biography will make a valuable addition to larger public libraries.