'God is dead', announced Nietzsche - before going on to abolish himself. Envious contemporaries of Nietzsche ridiculed him as a mad man - and yet they came closer than they knew in characterising a philosopher in whose thought ambivalence approximated to disintegration of the self. While the nineteenth century's coherent, consistent systems of certainty came crashing down ingloriously at the very first touch of the twentieth, Nietzsche's discourses...