Hey, who doesn’t love a good retrospective courtroom drama, or a tasteful picture about a smart writer having a think? Taking place after the most dramatic action it describes, Margarethe von Trotta’s Hannah Arendt bears a certain burden of innate narrative slackness. This, you’ve been warned, is a film about ideas — chiefly that the mere suggestion of evil’s banality could have been internationally scandalous once. But so it was when New School philosophy professor Arendt, having covered the 1961 trial in Jerusalem of genocidal bureaucrat Adolf Eichmann for the New Yorker, declared the man a willful nobody, “incapable of satanic greatness.” Also, she assayed the complicity of Jewish authorities in mass-killings of their own people. This was not a way to win friends, although in retrospect it has been shown to influence people. Here Arendt is played by Barbara Sukowa, who, in her trustworthy erudite poise, has the peculiar advantage of periodically resembling PBS NewsHour correspondent Margaret Warner. Without much actorly stuff to do, Sukowa makes the most of scrutinizing the trial, reflecting on the tutelage (and more) she had from Martin Heidegger (Klaus Pohl), smoking and thinking in her book-lined office, smoking and thinking in a forest, and not getting thrown, much, by hate mail or friendly accusations of arrogant detachment. Meanwhile the American intellectuals in her midst seem archly hammy, either because von Trotta and Pam Katz’s script can’t quite nail their vernacular or maybe because their dialogue was dubbed in postproduction. (Hard to tell.) In any case, the film does effectively substantiate the claim, as Heidegger once put it to young Ms. Arendt, that thinking is a lonely business.