Unsurprising, perhaps, that a film marketed for its fleeting perversions is, all told, a simple love story between two men. A Dangerous Method is one prom night away from Freud and Jung: The College Years, naively capturing the formation of modern psychotherapy amid the burgeoning friendship of its architects.

Keira Knightley’s role in all this has been, if not exactly oversold, then certainly mischaracterised. Sabrina Spielrein is a profoundly troubled young woman. Knightley imbues her with violent tics that would have you believe a dislocated jaw, so distended is its appearance. Upon her arrival in a Zurich hospital, she is cared for by Carl Jung (Michael Fassbender), a psychiatrist with a keen interest in the virgin field of so-called talking therapies. Their sessions – akin to more modern practices in all but formality – are witness to Jung slowly unpeeling a childhood beset not just by violence, but the torment of her having enjoyed it.

It is clear how David Cronenberg’s film could be confused with a more sordid exploration; likened to a yesteryear Secretary, perhaps. Yet far more profound than its brief moments of masochistic punctuation are the scenes between Jung and Sigmund Freud: his friend, confessor and rival. Their relationship spans several years, and shifts with time. In the beginning, they relate as eager mentor and student, untroubled by discussions lasting 13 hours without pause. Despite his own theories oftentimes being dismissed as spurious, Jung quickly found Freud – already in his 50s by the time of their meeting – an altogether more intoxicating prospect than he had bargained for. He would later caution a friend that “he’s so persuasive; so convincing. He makes you feel you should abandon your own ideas and simply follow in his wake”.

Spielrein is not the third point of a love triangle. Instead, her function is as a point of divergence for the two men. In finally relenting to his patient’s sexual frenzy, Jung is humiliated; scolded for his childish indiscretion. Relations sour further when Freud learns of his friend’s expanding interest in the occult: in the mystical voodoo of tarot and the supernatural. Such fascinations seemed evidence of an intellect in disarray, unable to reconcile its primal drives with an otherwise ordered and idealised life. It was to be a fracture that manifested not only in Jung’s crumbling relations with Spielrein and Freud, but in that of his wife, Emma, and Otto Gross: a confidante whose own ideas on sexual morality would ultimately give rise to those very perversions.

Two titans of philosophy, given body by compelling performances. Fassbender, to whom cinema seemingly owes an entire year of box-office receipts, is the embodiment of denial in a role that sees his intellectualism transformed into paralyzing guilt. He certainly has the face for it. As depicted, Freud is more austere than popular perception would have it, and little room is found for his infamous drug habit. Vigo Mortisson succeeds his deranged turn in Eastern Promises by disappearing into our most famous of thinkers, not by means of prosthetic, but in adopting a rigidly disciplined manner wholly removed from his own.

These characters employ learned gamesmanship in a headfirst dive into the pool of repression. Nonetheless, at a brisk 90 minutes, A Dangerous Method is terminably sleight. Were it not for the weight of Fassbender and Mortensen’s respective performances, the film could easily have collapsed into pompous melodrama. Thankfully, it consistently punches above its weight. Here is the picturesque origin story of a now widely-practiced field. It was not always thus. “Columbus had no idea what country he’d discovered. Like him, I’m in the dark”, Freud conceded. “All I know is I’ve set foot on the shore and the country exists”.