This is a towering biography of a giant intellect.The author sheds light on the varieties of darkness that shade the life and thought of, arguably, Germany's most influential 20th-century philosopher. His book also gives an excellent account of Heidegger's 'existential' ideas, highlighting the inimitable charisma surrounding both his writing and person. The manner in which he weaves Heidegger's thinking into the intrigues of his life makes for fascinating reading - nowhere more so than in Heidegger's relationship with Hannah Arendt, his secret lover in the 1920s and his loyal advocate after the war. Safranksi's biography is brisk, lucid and illuminating. We like to think that good writing makes for good living. Great minds are not always great moral beings. That such blindness could in this case partner some of the best philosophical work of this century is a puzzle indeed. Heidegger may have come close to some kind of reckoning when he confessed after the war: 'Nietzsche undid me!' The attempt to assume the role of superman going 'beyond good and evil' in order to think and live dangerously leads to moral blindness. What still shocks is that this very attentiveness to the dark destiny of the West goes hand in hand with an extraordinary moral insensitivity: the equation of agriculture with Auschwitz. Safranski explains the context of such a statement - the domination of every aspect of modern life and death by technology, which is itself a symptom of our forgetfulness of Being. Thus he could, for example, argue that 'the motorised food industry is essentially the same as the manufacture of corpses and gas chambers'. Enthralled with mountain peaks, he ignored life down in the valleys. Entranced with the big question of Being, he forgot about the needs of ordinary human beings. His friends understood that, even though he was one of the most profound thinkers about the modern destiny of Being, he was incapable of sound judgement at a moral level.

The fact that most of Heidegger's intellectual admirers after the war were Jews lucky to escape the holocaust (Hannah Arendt, Paul Celan), left- wingers such as Sartre and Marcuse, or Resistance leaders such as the poet Rene Char, is a token of just how puzzling the philosopher's brief conversion to Nazism in 1933 actually was.

Martin Heidegger by Rüdiger Safranski