Felicity Jones is a master of understatement.

Sadly, gender semantics get in the way of calling her “a mistress of understatement,” but as Jones knows, gender semantics are often obstacles for women.

In “On the Basis of Sex,” in theaters on Dec. 25, Jones stars as Supreme Court Justice Ruth Bader Ginsburg. Writer Daniel Stiepleman (Ginsburg’s nephew) and director Mimi Leder follow the future jurist from a young mom attending Harvard Law School in the late 1950s through her first landmark gender discrimination trial in 1972.

It’s the sort of film viewers may bawl at the end of, but these are tears moved by neither by triumph or tragedy. They are tears of —

“Relief? It’s a relief isn’t it?,” Jones offers. “The film shows sometimes change can happen. Because sometimes one gets a little um, disheartened.“

The actress pauses. She takes a sip of water, which she has poured herself, and then she finishes her understatement in a calm, collected English accent: “One gets a little disheartened by the present situation.”

Jones says this at a hotel less than a mile from the White House, where “the present situation” is continuing to dishearten, infuriate and enrage many American women.

“We still have to keep fighting against much of what Ruth was arguing against,” Jones says. The academy award nominee is wearing a chic and professional gray wool pantsuit, and seems far more at ease than the young Ginsburg she portrays.

Despite her English upbringing, Jones understands the challenges facing women in American politics, past and present. She spoke with The Lily about gender roles, growing up on all-male sets and the notorious icon she plays in the movie.

The Lily: As a British actor, how were you able to take on a role that required knowing the ins and outs of the American political system?

Felicity Jones: Much of what Ruth was arguing against is still very much in play. You’d have thought the film was going to be in this distant and dusty past, but the issues are as relevant as they ever have been. My belief in her, and what she’s about and what the film said was so great, I couldn’t pass up the opportunity. So I just became completely detail focused, and obsessive about those details, and my responsibilities to inhabit Ruth.

TL: Could you define “obsessing over details’?

FJ: It’s every aspect, on every front: Physically, emotionally and intellectually, you want to understand the world that the character is navigating, and do justice to the justice.

TL: Did you have any tutoring in law? Or read any of RBG’s decisions?

FJ: Yes. A lot of her cases are online. You can listen to them, and that was really, really helpful. I spent a lot of time listening to Ruth Bader Ginsburg’s vowel sounds. Her vowel sounds shift and change. [She faced] a lot of snobbery, being from Brooklyn. Most people had a more standardized accent, and that was fascinating, channeling [her Brooklyn accent]. When she gets upset or angry or cross, you hear the Brooklyn vowel sounds coming through much stronger. She was coming up against such an ingrained patriarchal system completely in the bedrock of the law, and how she navigated that, how she harnessed that anger and how she brought people over to her side is fascinating. She does that in the tone of her voice, and the way she speaks, and the clarity of her argument. She was an incredible writer. She had Vladimir Nabokov as her tutor at Cornell.

TL: I didn’t know that.

FJ: It explains so much about her care for words, her honoring words and even in her speech. When I went to meet her, it was interesting to see how slowly see speaks. She takes great pause before she says something, because she knows words are very, very, powerful.

TL: But until late in the film, Ruth he has some difficulty speaking in court. She’s been teaching at Rutgers, because law firms didn’t want to hire a woman, and a Jew. Is it fair to say that she has to learn to let confidence in her written words embolden her public speaking skills? I think her husband Marty [played by Armie Hammer] says something like that.

FJ: Absolutely. It was something that she knew very early on. In the film, obviously, [we had to] find the drama in the story. But I think she had an understanding of how persuasive she could be, that she did have the power to change people’s minds.

TL: You are best known for playing physicist Stephen Hawking’s wife in “Theory of Everything.” This new movies puts you back in the 1960s. Did you think about Jane Hawking while you were preparing or making “On the Basis of Sex”? And did you take any satisfaction in getting to play a woman from the same time period who is much more self-actualized?

FJ: There are a lot of similarities in these two women trying to make their way in a deeply patriarchal society. They are both trying to navigate this incredible pressure to be appealing, to be ladylike, to be inoffensive, to meet all these expectations of their gender, and not to be disruptive. Ruth learns to do that in a more sophisticated way.

TL: I don’t want to be shallow, but can I ask about the clothes? Ruth has some pretty sparkly moments in this film.

FJ: No, that’s not shallow. The clothes are equally fascinating. ... Ruth is a punk icon because of her love of style, and her consistency of style more than anything. In the vein of someone like Anna Wintour or Karl Lagerfeld, Justice Ginsburg also has stuck to what works for her. The collars are iconic, and I think an icon is made through repetition. She found what works for her.

TL: Although early in the film, she can’t even decide what dress to wear to a dinner with the dean of Harvard Law School [played by Sam Waterston].

FJ: So much of playing the role was showing someone finding her way, and showing how someone becomes an icon. She didn’t start off like that. She went into the world much more hopeful, and kept getting knocked backed and kicked back. It’s interesting showing how someone has to get tougher. How does she navigate that? [Ginsburg] has said herself that in the ’70s, she didn’t want to waste time using hair curlers. The gender stereotype had shifted, and the expectations had changed. She was saving all this time in the morning by just pulling her hair back. It was about pragmatism. She’s a very busy woman who doesn’t want to spend hours thinking about her hairstyle.

TL: She gains more confidence. The fashion traces the arc of the story.

FJ: Exactly. One of her first lines is, “Which makes me look more like a Harvard man?” She’s in the minority, and at first, she’s trying to fit in. but what we start to see is a woman who is saying, “I am going to do this on my own terms.” The society changes, and she realizes she doesn’t have to conform. But initially, it’s frightening. It’s nerve racking.

TL: Those opening scenes are scary, with just a sea of men marching across Harvard. But that was reality. She was one of nine women in her class.

FJ: I totally identified with that feeling of being in the minority and being an outsider from growing up on film sets. Often, there were just a handful of women, and that is not best situation to be in. It’s a much more harmonious when you have 50/50 in the workplace. Men and women both benefit from that.

TL: I love how the first time we see Armie Hammer’s character, he’s feeding their baby in a high chair.

FJ: From such a young age, [Ruth and Marty] were defying gender norms: The idea that the man should be tough and the one going off to work and the woman should stay at home. They pushed against that continually, and that’s what Justice Ginsburg is saying: the greatest shift will happen when men are given equally responsibility to look after children as women.

TL: There’s no meet-cute in this movie, no romance. We just meet them as a couple.

FJ: Exactly. What’s been so fascinating at screenings has been the response to the presentation of masculinity in the film. That is so important to the story. There aren’t many films that address that, a couple functioning in a very healthy way. This relationship is not about being macho for either of them. There are not competitive. And it’s important that people see that as a possibility for men and women.

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