Well, Mrs. Perkins mostly stays put, except when she takes the girls away on vacation. More mercurial is Aline Bernstein (Nicole Kidman), a married theatrical set designer who has adopted Tom as her protégé and appointed herself his muse. This makes her Max’s rival, and also the most interesting and unpredictable person in the movie, even though — or perhaps precisely because — it lacks the imagination to know quite what to do with her.

Instead, “Genius” sighs with palpable nostalgia for a supposed golden age of masculine artistic potency and paints the struggle for self-expression in familiar sentimental colors. For Tom, writing is the unbridled expression of the life force, something Mr. Law indicates by hollering and gesticulating and allowing a stray lock of hair to fall just so across his brow. Mr. Firth’s performance is equally broad, even though he’s supposed to be the more uptight partner in this bromance. He grimaces and sighs like a vaudeville Puritan.

But the actors can perhaps be forgiven, since they are continually pushed into scenes that seem designed to halt subtlety in its tracks. The most egregious of these — in which Tom drags Max to a sweaty nightclub in Harlem, pontificating on the spontaneous energies of jazz and boogieing with the working girls at the bar — adds a dash of racial condescension to the cocktail.

It’s dispiriting to see a movie about interesting real-life characters reduce them to clichés, making them less vivid, less fascinating, less charismatic than they must have been. (It’s also a bit disconcerting, though hardly surprising at this point, to see yet another movie with important figures in American history portrayed by British and Australian actors.) “Genius” is full of talk about art, life and greatness, but it’s only talk.

“Genius” is rated PG-13 (Parents strongly cautioned). Cigarettes and other examples of old-fashioned naughtiness. Running time: 1 hour 44 minutes.