Watching the audacious French actress Emmanuelle Devos in “Violette” is like observing an MRI of a female nervous system at full sizzle. Anger, lust and pain pinwheel across her features; her posture telegraphs spasms of elation and distress. She plays Violette Leduc, who has been called France’s greatest forgotten writer. Her erotically charged memoirs and novels impressed Sartre, Camus, Cocteau and Genet; she described passion as frankly as any male author.

We meet Violette in late 1944, a survivor of two world wars and numerous intense, volatile affairs with women and men. Self-conscious about her plain looks, uncertain of her prospects as she approached 40, an incandescently intelligent social misfit, she was practically designed by fate to be a novelist. Devos channels those raging emotional tides in a performance that is a major achievement.

The opening is a terrific stage-setter. Violette races through nighttime woods, a black-market food smuggler on the run from the authorities. When she arrives at the farmhouse where she is lying low, the owner barks “Money!” (she’s behind on the rent) and “Door!” (she didn’t close it). Throughout the film, doors literally close against Violette, emphasizing her outsider status, and financial worries hover like vultures. Turning every scene into an emotional tightrope act, director Martin Provost sidesteps the inertia that can afflict literary bio-pics.

Moving to Paris immediately after the war, Violette finds a mentor, benefactor and unrequited crush object in feminist writer Simone de Beauvoir. A dour, cool intellectual, she recognizes Leduc’s iconoclastic talent and introduces her to like-minded publishers. The provincial Leduc, who camouflages her insecurity with ostentatious clothes, is a visual joke beside the severely chic Beauvoir (willowy Sandrine Kiberlain).

Leduc, whose autobiography notes, “My mother never took my hand,” finds the withholding aristocrat irresistible. The lovelorn, strong-willed Leduc, who experiences everything in her body, wants affection. Hyper-rational Beauvoir, who exists solely in her mind, offers only encouragement. Their clash of personalities becomes a psychosexual tête-à-tête, never quite fusing or breaking apart. There’s a rich irony in two such articulate creatures being unable to communicate.

Another angle into Leduc’s mind arrives when her despised, beloved, take-charge mother Berthe (Catherine Hiegel) arrives on the scene. In a snap, Violette turns into a simpering middle-aged schoolgirl who can’t dress herself without Maman’s help. Provost richly evokes the period setting. Balancing technical artistry and dramatic pull, he leaves a lot unsaid, telling the story in impressionist dots and dashes. It has no formal dramatic structure, and yet what’s there is so wholly felt that it seems vividly lifelike. The gale-force urgency of Devos’ performance is sometimes too wrenching to watch, yet too gripping to ignore.