One reason Jane Austen’s novels have been so much adapted to film is that they provide a pleasure in plot and dialogue that has been rare in Hollywood since the fasttalking Silver Age of film.

Because they traverse an invisible matrix of manners, Austen’s characters go to great lengths to be explicit and complete in their communications. Indeed, Austen’s characters always communicate at two levels; their polite conversation is overlaid with silent discretions and meanings – exactly the kind of thing an actor can supposedly express.

It is the preoccupation with manners, rules, and other “truths universally acknowledged” that makes Austen’s plots timeless, and inspires adaptations like “Clueless” or “Bride and Prejudice,” which set the stories in the ritualized teenage microcosm of high school or modern-day India, respectively.

Straight adaptations, set at or near Austen’s own time and played according to her rules, have both the advantage and disadvantage of drawing upon Austen’s own language.The mid-1990s saw Douglas McGrath’s screwball “Emma,” starring Gwyneth Paltrow, as well as Ang Lee’s moving “Sense and Sensibility,” starring Emma Thompson. Each production was noble in its own way, preserving the frank, articulate spirit of Jane Austen even as they redacted her stories of female friendship into vendible romances.

That there has been no major film version of “Pride and Prejudice” perhaps owes to the unrivalled 1995 BBC miniseries,and especially its Darcy, Colin Firth. The trick to any production of “Pride and Prejudice” is Darcy, who must be cold before he is warm.

Mr. Firth convincingly bundled intensity with rudeness, planting the seed of Elizabeth’s (Jennifer Ehle) eventual admiration. In doing so, he actually inspired Helen Fielding in writing “Bridget Jones’ Diary,” thus making “Pride and Prejudice” the template for the entire chick lit genre. He also played the corresponding character in the film adaptation of Ms. Fielding’s book.

Besides Darcy, there is one question to ask of any “Pride and Prejudice” production: How does Lizzy compare to her elder sister, Jane? Jane is meant to be more beautiful, flattering the reader’s good taste in preferring Eliza. This dichotomy is usually glossed by making Jane blonde, and Eliza brunette, (although a minor – unwatchable – 2003 production made Eliza blonde and Jane Argentinian).

Eliza’s relative modesty informs the plot’s great puzzle: Does her eventual engagement to Darcy – who is twice as rich as Jane’s bridegroom – symbolize the triumph of complexity over innocent good looks? Or do they simply recognize one another’s pride, prizing what anyone else would find difficult?

The best productions honor the latter interpretation, emphasizing the privacy of Eliza’s evolving hopes, while the worst – that is, the new “Pride and Prejudice” – disperse both, shrinking the second half of Austen’s novel, figuring Eliza as a lucky girl who overcomes a misunderstanding.

As Darcy, Matthew Macfadyen, an action star from British television, is lukewarm. His Darcy looks dull and virginal, a slacker who wears open-throated shirts and whose aloofness sounds like cluelessness. He is not the catch he should be. Keira Knightley, herself an action heroine, substitutes her aggressive, tomboyish sparkle for the self-possession an Eliza Bennet needs.

This is a teasing Eliza, who suffers more visibly than Jane and laughs almost as easily as her foolish little sister Lydia. Ms. Knightley’s face is too handsome to make a convincing Eliza, though it has a discriminating air, and it is not Ms. Knightley’s fault that director Joe Wright has imagined “Pride and Prejudice” as a thrill for teenage girls, of whom Ms. Knightley must play avatar.

This “Pride and Prejudice” is no Merchant-Ivory scrimshaw; it provides little refuge from the deafening fare next door. The sound of feet-on-wood dominates the crucial country ball scenes, which sound like “Riverdance.”At uncertain moments the camera comes unhinged, to bob like a butterfly at waist level, watching as Mr. Macfadyen tries to figure out what to say to Ms. Knightley. Mr. Wright even inserts one scene in which Eliza stands on a craggy bluff, plumbing herself like a character out of D.H. Lawrence.

Stylish vertical lines triumph in costume; the Bennet home features a Borzoi and a wrecked, undersea color scheme. It seems less important that the Bennet sisters’ home is entailed to the male line than that they generally inhabit the Ralph Lauren creation myth.Their father, Donald Sutherland, is predictably dear; Judi Dench should have been more cutting as Lady Catherine de Bourg.

Worst, though, Austen’s dialogue has been poorly edited. The “accomplished lady” scene, in which Eliza must debate Darcy on the subject of pride, while Jane lies sick upstairs, is particularly difficult to follow. After Eliza climbs into her carriage, to return home with a recovered Jane, Darcy brushes her hand,giving up the game before it has started. Mr. Sutherland’s Mr. Bennet delivers his dour punchlines, as do all Mr. Bennets, but this scriptwriter gives them a wobbly setup.

In fact, this “Pride and Prejudice” has only two things to recommend it over the celebrated BBC production of 10 years ago. Its players, at the aforementioned balls, are much more lively.And its Lydia, played by 18-year-old Jena Malone, is terrifying in her youthful folly.

Why is today’s Austen movie so much poorer than last decade’s? There are many answers to that, not least the talent and taste of its creators. But it is interesting to note what both say about the era that created them.

When Laurence Olivier played Darcy in a 1940 “Pride and Prejudice,” the film’s attitude toward England itself was studious, even enthusiastic. It featured a Punch & Judy show, Waterloo is remembered as last year’s news, and bookish Mary purchases a book by Edmund Burke. His enunciations landed on the same spectrum of brave hauteur as any contemporary star’s mid-Atlantic accent. His and Austen’s Englishness seemed similarly respectable.

Since 1940 England has come down in the world; as a film set, it is known, mapped, and eminently manageable.It is its own genre,trading on diction and a unique notion of the pleasant. Powdered wigs and redcoats stimulate an electric current of near-irony in modern audiences, and Hugh Grant, who acted in the 1995 “Sense and Sensibility,” personifies the modern uses of Austen’s modest personalities.

But this “Pride and Prejudice” advances a cliche even more ridiculous than that epitomized by Hugh Grant: More than once I mistook some of Eliza’s younger sisters for hobbits. If Gwyneth Paltrow’s “Emma” existed in a toylike world, a kind of whimsical Christmas ornament, suggested by that film’s opening titles, Keira Knightley’s Eliza inhabits an almost Medieval fantasy realm, in which she happens to be pursuing a love interest.

Darcy’s first proposal to her, the hinge of the novel, takes place not in a room of socioeconomic proportions, but on a grand rainswept portico in the woods, possibly a confected ruin or temple.Her England is not foggy, but misty. In the 1990s Austen was a gold mine of sexual irony; now we have Elizabeth Bennet standing on a mountaintop. Austen’s books, so accommodating and realistic in their construction, have become a medium for a country that is increasingly imaginary.