The days are long gone when philosophers in the Anglo-Saxon tradition could airily dismiss Heidegger’s magisterial Being and Time as based on a mistake of language. His central importance in twentieth-century thought is now unquestioned. Sartrean existentialism, the philosophical hermeneutics of Gadamer and the deconstructionism of Derrida all have acknowledged roots in the work of Heidegger. His late writings which depict mankind as the ‘custodian of Being’ fit well with the ecological concerns of the present-day, and his advocacy of ‘thinking’ as opposed to ‘philosophising’ is in accordance with a growing suspicion of the worth and adequacy of philosophical systems as such. Along with this widespread recognition of the power and profundity of his thought, however, it is also necessary to take stock of the fact that Heidegger was an enthusiastic proponent of National Socialism and an admirer of Hitler.

There have been attempts to downplay the Nazi connection by his admirers and, not least, by Heidegger himself. Hugo Ott, as a historian rather than a philosopher, has undertaken the task of documenting the extent and nature of his involvement with the movement. Whilst there may be cavillings at some of his interpretations, there can be little doubt that his findings are based on scrupulous attention to the available documentary sources. There can be little serious doubt either as to the truth of his general conclusion that Heidegger’s associations with National Socialism were deeper and longer-lasting than has generally been recognised, and that Heidegger’s own subsequent statements about the matter were evasive and inadequate at best, and often downright mendacious. Indeed, it is questionable whether Heidegger ever recognised that he had been fundamentally mistaken in his espousal of the Nazi cause; nowhere in his writings is there an unequivocal disavowal of his former enthusiasms.

In a letter to Jaspers, Heidegger once spoke of ‘two thorns in my flesh – the struggle with the faith of my birth, and the failure of the rectorship’. The faith of his birth was Catholicism. Heidegger’s upbringing was as a child of humble origins in the conservative and devoutly