Directors Petra Epperlein and Michael Tucker have taken on a gargantuan task with their documentary The Meaning of Hitler. The title derives from a 1978 book by journalist Raymond Pretzel who published under the name Sebastian Haffner. Epperlein and Tucker conduct a series of interviews as they explore the lure of Nazism in its heyday and in the present. Making visible use of a clapperboard, the directors obviously aren't trying to create a seamless illusion. Interviews with writers such as Martin Amis, Yehuda Bauer, and Saul Friedlander mix with archival footage, location visits (Hitler's underground bunker), and cinematic references including Oliver Hirschbiegel's Downfall. Offering historical insight, small observations (Hitler never really had an occupation), and analysis, the documentary devotes too much time to Holocaust denier David Irving who filed a 1966 libel suit against American historian Deborah Lipstadt. Irving lost, a story told in the 2016 film Denial in which Rachel Weisz portrayed Lipstadt. You could do a lot worse than to check out the many books written by those interviewed. Early in the film, Amis sounds what might be the movie's dominant note: The most interesting thing about Hitler, he says, is that he resists understanding. Epperlein and Tucker are most effective when they take apart Leni Riefenstahl's Triumph of the Will, exposing the absurd pomposity of orchestrated mass rallies. You'll also find references to Trump and the current ascendance of right-wing groups globally and in the US, as well as a look at the fervid idolization of pop-cultural phenomena such as the Beatles. There's a risk in making an essay-like documentary. The movie can seem meandering and digressive. Epperlein and Tucker don't entirely succeed with a cards-on-the-table approach that isn't afraid of unanswered questions. Their movie tends to be a choppy, piecemeal effort in which details tend to be more intriguing than any attempted thesis.