Toward the end of 1888, a few months before he collapsed in a Turin square tearfully embracing a mistreated horse, Friedrich Nietzsche undertook to assure the world he was to be a destiny, “no mere man, but dynamite.” One day, so he announced in Ecce Homo, his name would be associated with the memory of something tremendous. Yet in explaining what his world-historical importance would be, Nietzsche stopped again and again to ask, uneasily, “Have I been understood?” And indeed has he? It seems that he was right to worry. Over the past hundred years, Nietzsche has meant all things to all people.

Not a movement – social, political, intellectual, artistic – has been without members who championed him as a guiding genius. There have been Nietzscheans of the Left and the Right. There have been Nietzschean vegetarians, sexual liberationists, Zionists, and socialists – also, of course, Nietzschean National Socialists. Undeterred by Nietzsche's well-known swipes at feminism and Christian “slave morality,” there have even been Nietzschean feminists and Nietzschean Christians. “Let woman rediscover her own cruelty, turn on the beaten and mutilate them,” cried Valentine de Saint-Point in imitation of the master. “Nietzsche was an extraordinary phenomenon,” Ernst Bertram explained in 1918, “within the history of Nordic Christianity.”

In Germany, World War I forms a watershed in this flood of Nietzsche interpretation. Before the war, Nietzsche's appeal extended across the German political spectrum and throughout the avant-garde, from radical expressionism to the conservative Stefan Georg circle; only the traditional Right of Church, Kaiser, and Nobility closed its doors to his influence.