Louis Vuitton’s Teenage Dream

PARIS — Fashion’s fetish for youth is the Gordian knot at its center: often the very generation that obsesses about it most is the one least likely to be able to afford to wear it.

The fixation has been attributed, variously, to the need for new ideas and/or seducing future shoppers, but on the penultimate day of the fall season, in the vaulted entry hall of the Musee d’Orsay, filled with 19th-century marbles hosting their first fashion show, Nicolas Ghesquière of Louis Vuitton offered a different explanation.

Adolescence is, he wrote in his show notes, a period of “inspiring idealism, hope for the future, for a better world.” A period when the tendency is to believe you can actually fix what the generation before you screwed up (at least if you aren’t being overwhelmed by how bad it is, which is the less romantic and possibly more realistic interpretation). Still, not a bad fantasy to be reminded of, right about now.

Ever since he took the helm of Louis Vuitton’s women’s collections back in 2013 Mr. Ghesquière has been time-traveling: through centuries, periods and movements. Why not through the ages of man (and woman)? When things look really grim, perhaps the answer really is to cherchez le teenager. Or the teenage self.

So Mr. Ghesquière delved into his memory box, remixing bits and pieces of the recent past, changing proportions, clashing patterns and messing with history in a complex game of dress-up and allusion.

There were oversize suiting jackets paired with trousers in Lurex and brocade and floral neckties. Some shirts had thick velvet scarves attached to their hems to create a peplum, fringed ends brushing the floor. Graphic pinafores in embroidered tweeds came with big, squared-off pockets at the sides like panniers, or in silk chiffon, layered over chunky sweatshirts in floral jacquard with photos by David Sims of weedy, disaffected ’90s youth, smack in the place of a cameo pin. The photos were also sprinkled over dresses and giant polo shirts, like posters from an old bedroom gone rogue.

At the end, some floaty embroidered dresses appeared under oversize striped rugby shirts or chunky knits. It was as if a kid had tunneled into the closets of her elders, tossed everything up in the air and seen where it landed. The combinations were sometimes awkward and often strange, but there was nothing vintage about them.

“Freedom is all,” Mr. Ghesquière wrote, “without directive or impediment.”

Even if the results didn’t look so interesting, it would be hard to argue with that. You find your liberty where you can.

Or try to. Giambattista Valli did it by navigating between the French youthquake of the 1960s and ’70s and the classic decorative arts, though his abbreviated minidresses in Aubusson prints, wide-angled flares and mousseline gowns seemed mostly trapped — not in amber but in his preferred rose-tinted lens.

Chitose Abe of Sacai did it via her signature hybrids, reimagining pieces normally associated with utilitarianism and protective cover in couture shapes, so tank tops and parachute skirts became graceful, drop-waist dresses; bubble puffers were merged with a trench yoke; bra tops woven into shearling to create an empire line; and bustiers born out of overcoats. Less chaotic and more considered than they have sometimes been in the past, they still forced you to check your assumptions.

And Stella McCartney did it in a collaboration with the 85-year-old artist Frank Stella. (Stella by Stella being, apparently, a bit of levity neither could resist.)

His oeuvre provided the inspiration for her collection, shown on the top floor of the Centre Pompidou with all of Paris spread out below and a recording of President John F. Kennedy’s 1963 “A Strategy of Peace” speech at American University in Washington playing as a prelude.

Designers have been borrowing from the art world for as long as they have been chasing the youth vote, and though the obvious referencing can often seem lazy or reductive, like the fashion version of a souvenir tee, here it proved inspired, challenging Ms. McCartney to stretch her own design thinking.

Sometimes the relationship was literal — knitwear pieced together along the lines of Mr. Stella’s “V-series” of lithographs, his bright “Spectralia” mélange reproduced on a swingy trouser suit and jersey dress, the graphic diagonal stripes on chunky fake furs and trouser suits a direct nod to his work. Sometimes it was more abstract, as in the structured lines of shoulders, billowing sleeves on silk blouses sliced open to (ahem) frame the arms and cool cotton denim boilersuits, the kind worn by artists in studios, treated to look like crushed velvet. But it always looked easy.

The wisdom of age, and all that.