Avid readers of biographies have asked me whether it is necessary for a biographer to be sympathetic to his subject: a good question but sometimes a vexing one.
In most cases, sympathy is an advantage, but if you are writing about a monster like Adolf Hitler, can you -- or, more important, should you -- sympathize? Well, no, but you do need above all to seek the fullest possible understanding of who this person was, what shaped him and how he came to be the force for evil and destruction that he undoubtedly was. This too can be a slippery slope toward exculpation; after all, as the French adage has it, "Tout comprendre, c'est tout pardonner" (to understand all is to forgive all).
The great virtue of Ian Kershaw's massive, probing two-volume biography of Hitler, now condensed into one thousand-page-long book, "Hitler: A Biography," is that it aims at -- and produces -- maximum understanding while never betraying so much as a hint of apologia for its rebarbative subject.
A professor of modern history at Britain's University of Sheffield, Kershaw has devoted his academic career to a study of Nazi Germany -- doubtless a depressing, but certainly a necessary, enterprise -- and this devotion shows in the scope and depth of the knowledge he brings to his biography. Indeed, it is interesting that he refers to it, at one point, as "a history of Hitler [that] has to be, therefore, a history of his power -- how he came to get it, what its character was, how he exercised it." You get the feeling at times that he is as much historian as biographer, which fits him superbly to his subject: