Sigmund Freud, working on his theories of psychoanalysis, came to the conclusion that everything comes from sex. Carl Jung, a younger man, experiments with Freud’s talking-cure methods, but has serious reservations about the idea that sex explains everything. And Sabine eventually purges her tormented mind of her unspeakable sexual fantasies, starts sleeping with Jung, and eventually comes to the conclusion that the sex instinct and the death instinct are inextricably linked.

Sabine’s contributions to the field of psychoanalysis have only recently come to be understood. It is clear in A Dangerous Method that her case of “hysteria” (a distinctly Victorian malady) spurred Freud and Jung into a competition over whose theories were the most valid, and they fought it out in paper after paper. The rupture between the men was “violent,” as can be seen in their voluminous correspondence.

While Cronenberg isn’t known for creating genteel period pieces, A Dangerous Method is certainly in line with the rest of his work and its obsession with the body, which you can see in The Dead Zone, The Fly, Dead Ringers and Crash (a film focused on the linkage between sex and destruction). At a press conference following the New York Film Festival screening of A Dangerous Method, Cronenberg was asked whom he felt more of an allegiance to, Freud or Jung. Cronenberg said he leaned toward Freud, because “I insist on the reality of the human body.”

Peter Suschitzky shot A Dangerous Method, and the screen is awash in golden light, making the buildings of Vienna look like giant, luscious wedding cakes. The detail in filming is exquisite in the interiors, the costumes and the shot set-ups. Carl Jung and Sabine go for an outing in a two-masted yawl with red sails bought for Jung by his wife, and we see the two of them from above, lying in the boat, their bodies intertwined in a perfect double-S; it is the most beautiful and emotional shot in the film.

Viggo Mortensen, a frequent Cronenberg collaborator, was an unlikely choice for the role of Freud (at least that was what I thought going in). But he turns in a terrific performance, witty and intelligent—a carefully constructed character study. Freud is contained in his own theories, and chewing on his ubiquitous cigar inevitably brings up questions of his own oral fixations. He is indulgent of Jung’s flights of fancy, at first, but eventually, as psychoanalysis becomes more accepted, he becomes concerned that Jung’s mysticism will throw everyone off the rails. This Freud has some bite. I was so taken with Mortensen’s constantly alert and cunning eyes. He was always thinking, sometimes on a current that flows in opposite direction of his dialogue. It is a very effective performance, and Mortensen, one of the best actors working today, has shown us something new in his repertoire. It bodes well for his life as a middle-aged actor.

Michael Fassbender is cinema’s current It-boy, with his gloriously erotic and tormented performance as Mr. Rochester in this year’s Jane Eyre, not to mention his superhero-in-training Magneto in this summer’s X-Men: First Class. Shame, his second collaboration with director Steve McQueen (the first being the harrowing Hunger, about the Irish hunger strike in 1981, in which Fassbender played Bobby Sands) is also screening at the New York Film Festival.

Fassbender wears the period of A Dangerous Method easily. The glasses, the mustache, the waistcoat ... all suit him. On a visit to Freud’s house, Carl Jung holds up the maid by his place at the table, so he can take enough food to feed 10 men. These men, coldly analytical in many ways, men of science, were also clearly men of great appetite.

But they were not pathologized for it to the degree that women were, and that was a disconnect in the film that could have been explored more deeply. It’s common knowledge that “uterus” and “hysteria” are closely linked etymologically (often meaning one and the same thing, therefore “hysterectomy”, etc.). Hysteria could be seen as a completely logical response to being a woman in a sexist society, the rigid controlling of their bodies, their fears of sex not being something neurotic but a valid reaction to not wanting to be pregnant for 50 percent of their lives. Jung and Freud, then, discussing things like penises, and orgasm, did so from a position of privilege and standing.

To understand and incorporate ravenous “appetite” into a buttoned-up world of convention and propriety was one of the goals of psychoanalysis. Our subconscious minds are filled with chaos and darkness. Jung and Freud tried to impose order.

Keira Knightley, as Sabine, also suffers from great hunger, and the violently jutting jaw and contorted limbs she shows in the earliest scenes are supposedly indicative of her illness. Knightley has never been better than in her awkward youth in Bend It Like Beckham, a part perfectly suited to her particular strengths as an actress. I never believe her in a corset and I never believe her in an apron or a bonnet. Knightley is obviously A-list, and gets a lot of great parts, but her acting craft is not up to the task of the parts she is given. Knightley, who did a lot of research into Sabine’s particular malady, is clearly reaching for the brass ring in her portrayal of hysteria, but that’s the problem. I see that strain; I see her reaching. While an actress trying to stretch and grow is admirable, Knightley is out of her depth here.

In the first scene, where we see her being dragged against her will into Jung’s hospital, Knightley duly writhes and screams. But I couldn’t help but think of another similar scene, from Norma Rae, when Sally Field is dragged out of the factory and forced into a police car. Director Martin Ritt gave Sally Field one piece of direction for that scene: “Do not let them put you in that car.” Sally Field played that objective within an inch of her life. When Knightley protests, by contrast, she looks like she’s acting.

The screenplay for A Dangerous Method wears its staginess openly in its commitment to long conversations between two characters. The screenplay itself is a “talking cure.” Sex is serious, and a topic worthy of in-depth discussion, and the sense is palpably real in A Dangerous Method that old barriers were breaking down, allowing the formerly unsayable things to come pouring out. At one point, when Sabine is telling Jung one of her more horrifying dreams and how she felt when she woke up, Jung listens quietly. When she finishes, he asks her a simple question, “Were you masturbating?”

She was. The acknowledgement of the darkness of her desires, his casual acceptance that sex drive doesn’t always play nice with societal norms, still feels like a revolution.

Our society continues to have trouble with the implications of the sex drive. Say what you will about psychoanalysis, either Freudian or Jungian, but it was a serious attempt to understand why we are the way we are. Although world events are rarely mentioned in A Dangerous Method, they are still accounted for in the film in an eerie way. As these two men hashed out their differences, discussing sex and death and dreams with one another, the Guns of August were already rolling into place. World War I would soon be unleashed upon the world.

Cronenberg directs A Dangerous Method with elegance and precision, highlighting the intellectual and sexual opposition between the three main characters. He is comfortable with long scenes where all that happens is two people talk to one another.

In today’s cinema, sex is often treated in a juvenile and cruel-minded way, and seriousness about sex is scorned as either pretentious or unrealistic. A Dangerous Method is a welcome change. Let’s talk about sex. It may cure us all.