Magalie Lépine-Blondeau and Pierre-Yves Cardinal in The Nature of Love (Music Box Films)

Opposites attract wildly in The Nature of Love, a funny, poignant, and occasionally bewildering film by French Canadian director Monia Chokri. Sometimes only semi-believable or even faintly bizarre, the movie wins viewers over with its charming leads and optimistic view of the power of love.

As for its 1970s stylistic flourishes and wild shifts in tone, viewer tolerance may vary. The setting is today, but Chokri uses ’70s-vintage backlighting, snap zooms, and grainy film stock that evoke a Me Generation–era nostalgia. You may not have heard Muzak since grocery stores switched to playing Fleetwood Mac, but you’re going to hear something like it in the film’s fluty, shag-carpet soundtrack. Such retro touches make Nature stand out, but also sometimes give its high emotions an air of weird unreality.

Radiant, low-key beautiful Sophia (Magalie Lépine-Blondeau) is a 40-ish college professor whose lectures are peppered with rather pedestrian reflections on love from the likes of Spinoza, Plato, and Schopenhauer. Sophia seems bored with her hyperintellectual husband. She may also be tired of her volatile mother, her in-laws, and her pseudo-artistic brother. With its dinner parties and aggressive name-dropping, Sophia’s social circle is a one-uppy, self-absorbed bunch out of Woody Allen, an effect enhanced by Chokri’s having them address each other in loud cross talk.

While Sophia’s getting the couple’s summer house redone, she notices her hunky contractor’s swagger and physicality. Sylvain (Pierre-Yves Cardinal) notices her too. Suddenly the two are knocking boots in sex so hot it shocks them both in scenes with a ’70s-style frankness and also a very ’70s message of fulfillment. Their new passion rocks her marriage. As Sophia gets to really know Sylvain, she’ll be immersed in an alien class milieu: His family reads like a loud, redneck mirror of her own. And she’ll have to handle someone with his own baggage and set of assumptions quite different than hers.

Nature boldly mixes up themes and moods. Sophia and Sylvain argue about racism, poetry, and her condescending tone of voice, then give in to wild passion. Class stereotypes vie with sympathetic insight. The atmosphere lurches from arch drawing-room comedy to erotic romance to lovelorn weepie. Events move fast, but scenes feel stately.

It helps in such a contradictory mélange that both leads are more than solid. Cardinal brings Sylvain’s gallantry and confidence to the fore. Lépine-Blondeau plays up Sophia’s feminine appeal with a counterweight of vulnerability and wit. The actors help the movie’s contradictions work because of the sense that Sophia and Sylvain really do love each other and can somehow benefit from each other’s personalities and skills. So vive l’amour, then. And remember, as Sophia quotes philosopher Vladimir Jankélévitch, “Real love is irrational.”