Letter from France: Why I love Paris in the autumn.

As a concept, “spring forward, fall back” fits Paris to a tee.

The global collective consciousness may well hold the City of Light to be paradise in springtime — spring rites and spring rain, the spring in the step of forward-looking dreamers who dream of April in Paris, and pipe that old tune. But what about the fall, alias autumn? If you ask me, the unsung season is an equally fine time of year to make Paris your own — often without the crowds or peak rates.

Forget the foursome of three-syllable months with ponderous names: “September,” “October,” “November” and “December.” Subtract the prosaic “fall” from the notation. Then try singing “Au-tumn in Paaa-ris.” It’s every bit as catchy as “A-pril.” As with April, the “thrill” of autumn sometimes rhymes with “chill,” though nowadays climate change can provide T-shirt weather right up to mid-November.

Weather — la météo — is the merest part of Paris’ fall-back season. For the French, fall stands for the end of enforced rural isolation with in-laws and enfants terribles, the end of sunburns and heat stroke — climate change again — and a return to the stimulating animation of this self-consciously enlightened metropolis, la Ville Lumière.

Fall isn’t l’automne in Paris anyway, it’s la rentrée — the re-entry. There’s the “political re-entry,” the “scholastic re-entry,” the “cultural re-entry,” and others still — re-entries for food, wine, fashion and industrial action. Falling back into place in autumnal Paris is as natural as gravity, the metaphorical space-capsule of life drifting leaf-like back to Earth, or plummeting like a chestnut, the correlative objective of la rentrée.Horse chestnut trees grow everywhere in town but are only noticed when flowering in spring, or raining uneatable fruit in fall. Their blossoms stand for spring, and their chestnuts symbolize fall. Parisians polish plump marrons d’Inde — horse chestnuts — as they hurry to work past second-hand booksellers along Seine-side sidewalks, or while jogging in the fashionable Bois de Boulogne. Some think of Proust, others of Hemingway. Unlike the author of A Moveable Feast, the stylish locals I know do not apply wax from the crooks of their nostrils to lend brilliance to the dark, spherical trophies they rub like worry beads. For many here, chestnuts are the amulets of this militantly secular society.

Fittingly for a city that’s a work of art in continuous evolution, come October the streets, sidewalks, parks and sweeping riverside esplanades of Paris exude Impressionist moodiness and stage-set atmosphere. Fog puffs up, dressing the Eiffel Tower in frilly underpants. Crispy golden leaves spin down from the nearly 100,000 trees on the city’s thoroughfares.

From an aesthetic standpoint, Paris becomes more likeable, more approachable, more intelligible in fall. As the sycamores and lindens denude themselves, a thousand architectural details are revealed — wreaths and garlands, composite capitals, or elaborate ironwork on balconies and rooftop pergolas. The long perspectives and obsessive symmetry suddenly make sense, whether or not you endorse the cannon-shot boulevards Baron Haussmann built over a century ago.

On them and every other usable surface, café and restaurant terraces spill chairs into the path of pedestrians. Terraces stay open despite the chill. Using them the way spiders use webs, the organizers of gastronomic or Bacchic festivals capture passersby. Half a dozen urban vintners including Jacques Melac in the 11th arrondissement pluck their grape bunches and make a show of it on TV. The lonely vineyard atop Montmartre is shorn of its grapes. Ditto the one at Bercy, in the gorgeous “Jardin de la Mémoire” on the Seine.

Other guzzlers celebrate the theoretical quaffability of that frothy purple beverage, Beaujolais Nouveau, but the less said about such activities the better. In the privacy of their homes, the owners of ready-at-last vintage wines raise bottlings from cellars into dining rooms with a sigh of satisfaction: who can drink a Château Margaux or Romanée Conti in July or August?

Making the mouth water wherever you wander is the woodsy scent of roasting chestnuts, the kind not intended for horses. It wafts up from impromptu, unlicensed stands on many a street corner, stands operated by legions of invisible aliens, many of them the kind the current French rightwing government would like to deport en masse.

Unsurprisingly fall is the best season bar none for food in Paris. From the mom-and-pop shops that have not yet been killed off by big business, out come the mounds of steaming sauerkraut, the sausages and hams, the pâtés, terrines and foie gras, duck confit and other fatty delicacies. They feature heavily at foires aux gras — “fat fairs” — and at self-styled “terroir” and “regional” markets.

Like the illegal chestnut sellers, legal market stands arise overnight to sell mushrooms such as the proverbial cèpes or champignons de Paris. There’s a lively fall food fair on the Seine facing Notre-Dame, and another on Pont Louis Philippe, the bridge linking the Right Bank to the Ile-Saint-Louis. Place Saint-Sulpice has one, too (and a Christmas market). Even the city’s weekly or twice-weekly street or farmer’s markets, often drab in other seasons, explode in fall with a kaleidoscopic harvest bounty, including pheasants in full plumage.

The royal treatment is lavished on the citizenry in October at the Chateau de Versailles: that’s the only time of year when the “King’s Kitchen Garden” sells its splendid, Louis XIV heirloom produce — 150 varieties of pear and 200 of apple — to the masses.

For gastronomes there’s one class of food that alone would justify an autumn trip to Paris: fromage. Odoriferous cheese-mongers’ grottoes display only-in-fall delights. My favorite is luscious, unctuous, oozing, eat-with-a-spoon Vacherin (aka Mont d’Or). But the parade of artery-plugging delicacies goes on. Those shoulder-to-shoulder chocolate shops of the chic Saint Germain district or the trendy Marais may sit empty in hot weather but bustle when temperatures drop. Bakeries beckon, three per city block, their steamed-up windows stacked with savory tarts and dazzling, caloric desserts, unnecessary yet essential to the pursuit of Parisian happiness.

Strange to tell, as the obesity pandemic rages elsewhere, most Paris natives remain slim. The French paradox, say some. Perhaps. Maybe it’s because people still eat fresh food here and attempt to enjoy themselves. They also do a lot of walking, talking and gesticulating in that inimitable, agitated, Parisian way.

Fall entertainment takes many forms. The mainstream, official, subsidized extravaganza of dance, theater and suchlike is le Festival d’Automne, while photography is honored this November by Paris Photo.

More excitingly, this is when denizens discover the Emperor’s new clothes and his new omelette too: the insanely complicated, unwearable creations of the haute-couture crowd, and the ludicrously uneatable food-art conjured by the Michelin multiple-star brigade. Fall fashion shows colonize whole quarters with tents and runways. There the initiated swoon over five-digit pheasant plumage, decolté designer rags, tears in fabric and tears on cheeks, pins, scars, exposed flesh, elevator pumps and mind-boggling corsets.

Meanwhile the celeb chefs’ serve up not vulgar food but “emotions,” thrilling, shocking and awing the susceptible leisure classes.

From sidewalk stands and old-fashioned cook-shops to the haute runways and $300-a-plate temples of gastronomy, the eating and fashion orgy can seem out of step with our troubled times. The recession? The ten-percent unemployment rate? Wars, terrorism, global warming and poverty? Yes, but not, apparently, in Paris “Intra-muros” — within the city walls now girded by a beltway. Here everything stays comfortingly the same thanks to that age-old edict, wealth.

Happily the hedonistic orgies do not unduly affect the lives of most Parisians or visitors. The noisy, up-all-night summer frenzy is finished by October, and a comforting, off-season quiet steals back on the brisk evening breeze. Because clocks fall back a vital hour, it’s easy to get out early and claim your favorite café table, the one with the perfect view from the Café de la Mairie, for instance, of homely Saint-Sulpice swaddled in scaffolding. The trio of joints on the downstream tip of Ile-Saint-Louis afford sidelong glimpses of Notre-Dame’s buttressed back. If you don’t mind dropping $10 for a café-crème and a croissant, the soaring belltower of Saint-Germain-des-Près is what you get at Les Deux Magots. But only if you can see, think and hear over the cellphones, BlackBerrys, iPads and other wireless destroyers of peace common at posh places.

That’s why I prefer to perch at unknown cafés and saunter in unglamorous neighborhoods. Here you soon discover the real Paris. Despite the re-entry’s animation, fall is the unrushed season, a time of inky newspapers on wooden sticks, of thick, well-thumbed novels, of deep yawns and slow trawls, of scattered sun and sodden tennis balls kicked for yapping lapdogs wearing gem-studded collars. The yawns are often caused by the well-thumbed novels, short-listed for the Goncourt and other literary prizes handed out in autumn.

Other urbane seasonal sports include avoiding the joggers, sprinters and speed-walkers who reappear in their thousands and devise novel ways to bump into, trip up, splatter and otherwise terrorize visitors and anyone who strolls at a normal pace. A different menace comes from Paris’ grizzled boule-bores. Refreshed by their summer break, they begin tossing their polished steel balls that hop, skip and jump under your feet on the sycamore-lined alleys of a dozen parks, notably the Luxembourg Gardens.

In fall, this most sublime of Paris parks drips with impossibly colorful, impossibly long, trailing chrysanthemums. Peer close up and you’ll see that the mums are trained along wire frames, the way pears are espaliered. They’re a merger of bonsai and topiary, unique, as far as I know, to Paris. Like the horse chestnuts, they signal the arrival of fall. They also highlight two hallowed days: All Saint’s Day, November 1, and All Soul’s Day, the 2nd. For the French, mums are memory flowers. Despite the much-trumpeted secularism of the République, the back-to-back duo of Catholic holidays draws countless Parisians into flower shops to buy chrysanthemums, or to parks and cemeteries to admire them.

Beyond the Luxembourg Gardens, the most astonishing displays of mums and other memory flowers are at Père-Lachaise cemetery, the repository of the nation’s Great and Good. At each turn in its ten miles of twisting, cobbled roads or looping dirt lanes you’ll find chrysanthemums marking family tombs, all 70,000 of them.

Many Père-Lachaise regulars object to a recent fad, imported like so many fine things from the “Anglo-Saxon” world: Halloween. It still startles me to see French children dressed with sartorial perfection as devils, princesses or pirates soliciting door to door. Paris apartment buildings are bank vaults, so kids attend lavish private Halloween parties instead, or cavort in parks and cemeteries, where they’re viewed with gimlet Gallic eyes.

Certainly, strikes and political snafus happen in all seasons. But French unions look forward with glee to la rentrée. Each fall brings its blend of industrial and social action. This year, the focus is pension reform: should the minimum retirement age stay 60, or rise to 62? The number of years worked, and the nature of the job, are supposedly factored in. So too is the death rate-steady at 100 percent. But with everyone here seemingly reaching 100, despite or possibly because of the foie gras and chocolate, the numbers no longer add up.

So elusive are statistics that when the nationwide late-September strike against President Nicolas Sarkozy’s reforms was held, the organizers counted 3 million participants, the authorities a mere million. What other country can still mobilize that many marchers — nearly all of them peaceful, orderly and well educated?

It’s uplifting to tap into the Parisians’ grim cheerfulness. Most are determined to keep social democracy alive, and many want to turf out the bonus-loving free-marketeers who denounce it as “the welfare state.” No wonder autumn marches become fêtes featuring wine and song — tea is rarely served at these left-leaning parties. Visitors and residents who don’t have trains or planes to catch sometimes find short strikes instructive, even enjoyable. For one thing, solidarity fills the air, and everyone walks or rides bikes, proof Paris thrives when public services shut down.

Feisty and opinionated, many Parisians look forward to la rentrée for another reason: colorful controversies and succulent scandals ripen like Vacherin in autumn. The 2010 season features a rerun starring billionaire Liliane Bettencourt, France’s richest woman, heiress to the l’Oreal cosmetics fortune, and Minister of Labor Eric Woerth, plus President Sarkozy himself, and a celebrity cast of glam photographer-artistes, bevies of society doctors, CPAs, lawyers and conservative party fundraiser-politicos.

Less consequential but even juicier to the culture-vulture set is the kerfuffle involving the mega Claude Monet exhibition at the Grand Palais. A magnificent retrospective with 170 artworks from 70 museums, it has everything — almost everything — to send Impressionism lovers to Seventh Heaven (the show runs until January 24, 2011). The “almost everything” is the missing pièce de résistance. It’s what keeps Paris chuckling, clucking, wrangling and lining up, not just at the Grand Palais, but also at the Musée Marmottan. Why?

Because Monet’s masterpiece, the one that gave Impressionism its name, “Impression, soleil levant,” isn’t in the Grand Palais show. It’s at the Marmottan, the centerpiece of a rival exhibition, “Claude Monet: son musée” (October 7, 2010-February 20, 2011). The Marmottan’s director has reportedly placed animosity above the public interest by refusing to lend the painting and then trying to steal the limelight. Where else could a dispute between museum directors grip a nation? Duels used to be fought for less. Now rivals lambast each other with sound bites. That’s civilization.

But follow the money for the real story: “Monet” sounds like “monnaie” — meaning coin, cash, money. The retrospective is expected to draw 700,000 visitors. Anyone wanting to see Monet’s misty vision of dawn breaking over Le Havre will have to pay twice for the privilege.

Monet famously captured spring in his paintings, but what better way to wind up a fall trawl than to segue from the Grand Palais to the Marmottan to a third helping of the master — his Waterlilies — at L’Orangerie? This lovely mini-museum is in the Tuileries, the city’s second-most sublime park. Like the Luxembourg across the Seine, the Tuileries distills the essence of Paris. The requisite horse chestnuts pelt visitors, and ice cream, pastries and gourmet fare are dispensed from outdoor cafés. The park’s seemingly endless perspective-physical and historical-runs from the former seat of royal power at the Louvre, past Monet at L’Orangerie, along the Grand Palais, all the way up the chestnut-lined Champs-Elysées to that crowning symbol of la République, the Arc de Triomphe, where the flame of French nationhood burns eternal, whether in April or autumn.

An American author and journalist based in Paris, for the last 25 years David Downie has been writing about European culture, food and travel for magazines and newspapers worldwide. His nonfiction books include Enchanted Liguria, Cooking the Roman Way, The Irreverent Guide to Amsterdam, and three critically acclaimed volumes of travel, food and wine in the Terroir Guides series: Food Wine the Italian Riviera & Genoa, Food Wine Rome, and Food Wine Burgundy. His travel memoir Paris, Paris: Journey into the City of Light, which Jan Morris called “Perhaps the most evocative American book about Paris since A Moveable Feast,” will be reissued in 2011 by Broadway Books. His latest books are Paris City of Night, a classic thriller set in Paris, and the forthcoming Quiet Corners of Rome (spring 2011). His website is www.davidddownie.com.

[Photos: Flickr | Luke Robinson; Luke Robinson; freethan; t3mujin; amymengel; randomduck; Celso Flores; felipe_gabaldon; Ryan S B]