“Hannah Arendt” opens Friday at Sundance Cinemas. Not rated, 1:49, three stars out of four.

In 2009, writer-director Margarethe Von Trotta and actress Barbara Sukowa made a film called “Vision,” about the life of a 12th-century Benedictine nun who fought against church elders over some of the doctrines of her church. Filmmaker and actress reunite for “Hannah Arendt,” another film about a strong-willed woman willing to defy all around her to pursue what she believes to be right. But this woman is by no means — for one thing, she smokes a lot.

Other than that, “Hannah Arendt” is a fascinating look inside the philosopher and writer, and in particular the one series of articles she did for the New Yorker that made her the most famous, and notorious. The magazine’s William Shawn (Nicholas Woodeson) assigned Arendt to cover the trial of Nazi Adolf Eichmann. As Arendt sat in the court, she didn’t see Eichmann as a monster, but rather a chilly bureaucrat who insisted that he was just a cog in a very large machine, serving his function, and as such shouldn’t be held accountable for the morality or immorality of that machine. When someone describes Eichmann as a scary creature, she responds, with a touch of wonder, “He’s a nobody.”

Arendt wrote about this in her New Yorker articles, coining the famous phrase the “banality of evil” to describe the atrocities committed by ordinary men who truly believe they are not doing wrong. The articles would come to change the way the Western world thought about the nature of evil, but at the time, Arendt was excoriated by her fellow Jewish thinkers as an apologist for the Nazi regime.

If they thought they could cow Arendt into recanting her articles, they had another thing coming. Sukowa (a frequent collaborator with Von Trotta going back to “Berlin Alexanderplatz”) makes Arendt a flinty, wily woman, always seeming to appraise people through the haze of her cigarette smoke. It’s both an amazing piece of impersonation and a subtle, canny performance that suggests the sharpness of Arendt’s thinking. But Arendt is not an unfeeling person — she dotes on her ailing husband Heinrich (Axel Milberg). She just has no use for nationalism. “I never loved any people,” she tells one colleague from Israel. “I only love my friends.”

Like “Vision,” “Hannah Arendt” is a story of what happens when ideas clash with emotions, the individual against groupthink. The film ends with a stirring defense by Arendt in front of her classroom that should convince anybody, but her detractors on the faculty are unmoved. They see her as a monster, therefore her views are monstrous, therefore they will not even engage with them.

Some of the film is a little stage-y, and some minor characters in party scenes speak as if they are reading directly from editorials, rather than talking as human beings. But overall “Hannah Arendt” is an engaging look at a small skirmish in one corner of 20th-century thought that illuminates an age-old battle between reason and emotion.