Writer-director Rebecca Miller makes her first full-fledged foray into romantic comedy with “Maggie’s Plan,” a clever triangle that stars Greta Gerwig as a New Yorker who, concluding that she can’t sustain romantic relationships, decides to become a single mother. But that’s before she falls for John, an adjunct in a university anthropology department and would-be novelist played by Ethan Hawke. He divorces his imperious wife Georgette (Julianne Moore), also an anthropology professor but a far more famous one, to marry her, but after a few years Maggie begins to regret her decision and comes up with a scheme that could just make all of them happy again.

“I think what happens with John,” Miller explained In a recent Dallas interview, “is less about her—and that she can’t have a relationship—but that there’s something not right about their relationship. What she comes to believe is that he’s never really left his wife.—which can be dispiriting.

“The thing about Maggie that I admire,” she continued, “is that she’s unlike most people in that she’s so honest—somebody who is not quite of this world. She doesn’t do things the way other people do them. She’s a really good person, even though she often messes things up. Her logic is usually sort of impeccable: ‘This is falling apart. You’re perfect for this other person, and I’m going to figure this out. It would be so wasteful not to. Otherwise I’ve broken up a marriage for nothing.’ It’s just so odd, because most people don’t do that. She has her own way of looking at things, and she’s really trying to live an honest life.”

Miller was enthusiastic in her praise of the three leads. Of Ethan Hawke, she remarked, “His performance was very generous and brave because he didn’t hold back any of the flaws of the character. He was just right out there. He was also very inventive. He thinks like a writer, but he’s also completely an actor. He said things to me that ended up influencing the movie. The things that he said made me change certain scenes. Actually Greta’s like that as well—very generous and creative, everything that’s best for the film. I felt she was a great collaborator.

“It’s same thing with Julianne, too,” Miller added. She especially praised Moore’s ability “to show breadth in a character” that could have seemed one-note. As Moore plays Georgette, however, “you realize that under this rather forbidding exterior is a woman who’s a very caring mother and has a deep love for [John].”

Miller was especially eager to discuss the academic setting of the film. Reading an early version of the script, a friend of Miller’s suggested that John and Georgette’s specialty sounded a bit like the so-called critical anthropology taught by internationally-known Professor Michael Taussig of Columbia University. “In their own world these people are stars. In fact, Greta studied with Taussig at Columbia,” Miller said. “She knew all about him. When I started to read about Taussig, I got very interested. When you start to really look into it, [his work] makes sense. What he’s doing is commenting on anthropology, but also using his own narrative as well.”

Miller quickly added that she emphasized the aspects of the discipline that could be made to sound ridiculous. “It’s really about character,” she said of the film’s academics. “I love absurdity, and I was interested in the absurd elements of it. I thought it was pretty ripe for comic interpretation.”

When asked how she thought actual critical anthropologists might react, Miller said, “I have a feeling they’re going to be pretty interested. I mean, after all, it’s fun to be kind of brought into popular culture in some way. It’s obviously a humorous take on it—it’s not a documentary—but I think there are elements of truth to it.”

Whatever their reaction, Miller obviously relished employing the academic setting. “One of my favorite things was the scene in the auditorium, where [John and Georgette are debating]. The whole thing is basically a fight between spouses. It was really fun to direct, and also to cut later. It reminded me a little bit of 1940s films, the kind of thing that would have been in a Spencer Tracy and Katharine Hepburn film, where you watch them at work and they’re brilliant people trying to dismantle each other while at the same time they’re just doing their job. It was really fun, and it felt natural to set it in that world.

“And also I live very close to the New School, and so the whole thing about shooting in an environment that I was very familiar with and feels like home was very nice, too.”