opinion of those who seek to provide "personalized" theories about the Holocaust and/or World War II as due to some defect, medical or otherwise, in Hitler. In his 2000 edition of The Nazi Dictatorship, Kershaw quoted with approval the dismissive remarks made by the German historian Hans-Ulrich Wehler in 1980 about such theories. Wehler wrote:Does our understanding of National Socialist policies really depend on whether Hitler had only one testicle? ... Perhaps the Führer had three, which made things difficult for him, who knows? ... Even if Hitler could be regarded irrefutably as a sadomasochist, which scientific interest does that further? ... Does the "Final Solution of the Jewish Question" thus become more easily understandable or the "twisted road to Auschwitz" become the one-way street of a psychopath in power? Kershaw shares Wehler's opinion, that, besides the problem that such theories about Hitler's medical condition were extremely difficult to prove, they had the effect of personalising the phenomena of Nazi Germany by more or less attributing everything that happened in Nazi Germany to one flawed individual. Kershaw's biography of Hitler is an examination of Hitler's power; how he obtained it and how he maintained it. Following up on ideas that he had first introduced in a 1991 book about Hitler, Kershaw has argued that Hitler's leadership is a model example of Max Weber's theory of charismatic leadership. Kershaw's 1991 book Hitler: A Profile in Power marked a change for him from writing about how people viewed Hitler to writing about Hitler himself. In his two-volume biography of Hitler published in 1998 and 2000, Kershaw stated, "What I tried to do was to embed Hitler into the social and political context that I had already studied." Kershaw finds the picture of Hitler as a "mountebank" (opportunistic adventurer) in Alan Bullock's biography unsatisfactory, and Joachim Fest's quest to determine how "great" Hitler was senseless. In a wider sense, Kershaw sees the Nazi regime as part of a broader crisis that afflicted European society from 1914 to 1945. Though in disagreement with many of their claims (especially Nolte's), Kershaw's concept of a "Second Thirty Years' War" reflects many similarities with Ernst Nolte, A. J. P. Taylor and Arno J. Mayer who have also advanced the concept of a "Thirty Years' Crisis" to explain European history between 1914 and 1945. Functionalism–intentionalism debate In the functionalism versus intentionalism debate, Kershaw has argued for a synthesis