Ernst Kantorowicz was a complex figure whose long incident-filled life seemed to embody many of the contradictions of the twentieth century. A Jew from a disputed area between Germany and Poland who fought on the German side in World War I, he first achieved academic success with Frederick II (1927), a work whose language, in Gabrielle Spiegel's words, often came perilously close to that of the Nazi party in its desire to see a reconstituted...