There's a lot of talk about sex in this drama, which isn't surprising given that Sigmund Freud is one of its main protagonists. Viggo Mortensen gives a refined, surprisingly buttoned-down turn as the father of modern psychology in this his third, intriguing collaboration with director David Cronenberg (following A History of Violence and Eastern Promises).
More talk means less action, so it's a change of pace for the latter man as well. Even if the subject seems controversial - and much has been made of a spanking scene featuring Keira Knightley - this is one of the least graphic, least visceral of Cronenberg's films, appealing instead to an organ much higher above the belt.
But as Freud might have said, old habits die hard. The director kicks off with a rather grotesque introduction to Knightley's 18-year-old mental patient Sabina Spielrein as she is admitted to a psychiatric hospital in Zurich in 1904. She kicks and screams and writhes around, pulling faces that would make Jim Carrey wince.
Fortunately, Knightley gets over the hysteria in just a few years with the help of Dr Carl Jung (Michael Fassbender) who is experimenting with Freud's "talking cure". Sabina reveals that she was beaten by her father as a child and finds sexual pleasure in pain, but after confronting this and beginning her own study in psychology, she tempts Jung into helping her relive the past.
If anything about this film is likely to offend it won't be the scenes of sadomasochism - which are actually quite restrained - but the way Jung tries to rationalise his sins. Not only is he a supposed 'family man' (with a permanently pregnant wife), he is a religious man so fervent in his beliefs that he considers specialising in the paranormal. These matters cause friction between the protégé and his mentor, who worries that Jung will bring their "movement" into disrepute.
The shifting balance of power between the two great minds is engaging to watch, especially because Cronenberg uses their actual correspondence in voiceover. Mortensen may seem more like the type to get his point across with a headlock, but in fact he has an aloofness about him that suits Freud brilliantly. He guards the high ground while Fassbender gets typically down and dirty, grappling with Knightley in one scene before wrestling with his mind and 'soul' in the next.
Knightley is bold, but her task is, arguably, the most difficult and the most thankless. While Sabina becomes a source of fascination for both men, she is too easy to dismiss as irrational. Her fierce intellect provokes interesting discussion with Jung on a theory linking the sex instinct with a sort of metaphysical death wish, but her heart always overrules her head, reducing her to the conventional woman scorned. Frankly, if Jung had a rabbit, you would fear for its safety.
Obviously, the love affair between Sabina and Jung is doomed from the start, but that doesn't come with any poignant sense of loss. Curiously, for all the unleashing of blows in the bedroom, Knightley and Fassbender seem to hold something back and it may be due to the very nature of this story; ranking emotion as the simple fallout from synapses firing in the brain. Ultimately, there's no danger of being deeply moved by this film - it's just a tantalising glimpse of part of what makes us human.