The film begins in 1928 Berlin with the chaotic backstage life of a haughty, grouchy Chinese illusionist, Wei Ling Soo, played by the magician Stanley Crawford (Firth). It's a promising start: Here is Firth, in regal, oriental garb and long mustache, disparaging autographs as “for mental defectives.”

More of this, and “Magic in the Moonlight” could have been a very funny movie. But Wei Ling Soo doesn't again perform, and instead the rest of the film feels oddly missing the jokes it seems built to convey. Crawford — a self-described “rational man” who believes in his art, not in actual magic — sets off to the South of France to unmask a medium, Sophie Baker (Stone), gaining renown for her prescient “mental impressions.”

They meet at the sumptuous Cote d'Azur home of the Catledge family, whose rich bachelor Brice (Hamish Linklater) swoons unapologetically for Sophie. A dance of distrust begins between the cocksure Crawford and the lithe, charming Sophie across a vivid, widescreen backdrop of cars, clothes and coastline.

Crawford, whose fiancee hasn't joined him on the trip, is both supremely confident in his realistic worldview (Nietzsche, he says, resolved “the God problem rather convincingly”) and abundantly unhappy. Audiences will surely see where the film is going as it sets up a quite rigidly explored dichotomy between blithe believing and scientific certainty.

It's an argument for illusion in our lives, no matter how fraudulent; for love, no matter how illogical. “Magic in the Moonlight” is a disbeliever's earnest plea to believe.

These are, of course, ideas Allen has long explored, and “Magic in the Moonlight” often feels like the kind of tidy New Yorker humor story the filmmaker might pen. Even with bright performances and lively chemistry between Stone and Firth, the movie is stale with the fixed rhythm of the written word, not alive to its images, despite the rich setting. (A quick aside: Is it possible to not have good on-screen chemistry with Stone? From Ryan Gosling to Spider-Man, she bewitches everyone.)

Allen is in complete control of the film, both its comic pacing and its philosophical quandary. But perhaps that's the problem: Like Crawford, “Magic in the Moonlight” needs to be less in control of itself. The film doesn't believe in magic enough.

“Magic in the Moonlight,” a Sony Pictures Classics release, is rated R by the Motion Picture Association of America for “a brief suggestive comment, and smoking throughout.” Running time: 100 minutes. Two and a half stars out of four.