The content of form.

FASHION, uninformed souls opine, is lowering and raising women's hemlines, widening and narrowing men's lapels. It reflects, they aver, nothing more than the greed of designers and clothing manufacturers, pressuring us to throw out perfectly good clothes before they wear out; or, worse yet, the vengeance of woman-hating homosexual designers on the female sex. There is even a moral ambivalence, as stated by a character in Albert Camus's The Fall: ''I am well aware that an addiction to silk underwear does not necessarily imply that one's feet are dirty. Nonetheless, style, like sheer silk, too often hides eczema.'' A sensible person is supposed to ignore the dictates of fashion, and simply be him- or herself. Like all half-truths this may be half true. But there is more to fashion than that, by half.

Fashion answers, or tries to answer, a profound human need: the need for change. Conservatives tend to pooh-pooh this need, except when they are out of office. The more literate ones will quote you Pascal: ''All human misery stems from one sole cause, which is the inability to be at rest in one's room.'' (One could also render ''demeurer en repos'' as ''stay put.'') The opposite of en repos is restlessness, which is where fashion comes in. Most of us cannot stay in contented repose either in a room or in a palace. We crave change because it is the cure, more or less, of the oldest known malady: boredom.

Do not underestimate the relationship boredom:change:fashion. Most simply put, boredom means being fed up with one's life, and change means doing something about it. But most of us are stuck with the sameness that is our destiny. We have scant control over other people, over the world; so we try to change what is changeable about ourselves. We want to feel like a new person; to achieve this, or the illusion of this, a modified appearance is indicated. Even a fresh shoeshine or boutonnicre has been known to renew us. A bit.

The great renewer, though, is fashion. We can't do much with our bodies: high heels or platform shoes will add a semblance of height; dieting, no easy task, will make us slimmer, if that happens to be the fashion. We can do a little more with our faces. For women, coiffures and makeup; for men, greater or lesser hirsuteness. But more can be done with clothes: with fashion or, as it used to be called after the French, the mode. Consider Sir George Etherege's 1676 comedy The Man of Mode, featuring the ridiculous Sir Fopling Flutter, based on an actual fop, Beau Hewitt. Sir Fopling is ''the prince of fops, the perfect product of Parisian taste of the day.'' Interestingly, he is a man; the earliest known victims of fashion were men. But so, too, were its earliest arbiters, notably Petronius, author of the Satyricon.

What cannot clothes do? You have thick legs? They can cover them up. You are short-waisted? The dropped waistline can lengthen your waist. Your behind is large? Flare out the skirt. You're a man with a tummy problem? Here's the double-breasted suit. Your chest isn't manly enough? Padded shoulders can create the illusion. And so on. All changes in fashion benefit some wearers; unfortunately, no fashion benefits everyone.

The reversals of fashion are, when you think of it, amazing. The flappers wanted to look boyish for reasons of sexual equality, so the look became flat-chested, tubular. When women are, or want to be, viewed as either good nursing mothers or sex objects, the breasts become built up or exposed. That calls attention to possible ambiguities. So, too, a bikini may imply equally love of tanning or lust for men. Ambiguities and contradictions are everywhere. In a given year, Paris may decree one thing, London another, Milan a third. Different designers in the same fashion center will diverge: do not expect a Ferre to look like a Versace or an Armani like a Zegna.

And yet, in hindsight, some sort of unison emerges. The Directoire low-cut dress with the high waistline gathered at the bust can be found on both the future Empress Josephine and the beauteous Mme. Recamier. Biedermeier, the less sexy German version, is not all that different. But everything changes, at a dizzying pace. Didn't Heraclitus, way back then, observe that you could not bathe in the same suit twice? Sorry, that was the same river.

Whether or not fashion is an art, it certainly behaves like one. There are the great couturiers, sold or copied by the department stores and boutiques, and all manner of cheap knock-offs. Just as you can hang on your wall an original by Manet, you can hang a Manet imitator or reproduction, or a piece of junk. The same goes for what you hang on your body. Of course, art comes into women's wear more than into men's, but it enters both. Men's ties, vests, shirts, and suspenders have been daring enough to compete with women's fashions. And, like other arts, fashion comes in for censorship. Puritanical societies have always tried to control fashion: Christian Lacroix would have had a hard time of it at the Spanish court in its Habsburg heyday. More significantly, artists have often worked, so to speak, hand in glove with fashion designers; so, for example, Sonia Delaunay created patchwork designs for Jacques Heim coats, worked for a textile company, and influenced Patou and Schiaparelli, among others. So Dali designed fabrics for Schiaparelli, and Saint Laurent co-opted Mondrian for a line of dresses.

Why should fashion be denied the status of art? Because it is functional? Is ceramics not art because one can eat and drink from it? Because it is cosmetic? Yes, it beautifies, but by means of something sewn, constructed -- not merely smeared on like a pomade. Clothes, to be sure, wear out, whereas a painting or statue remains; but in the light of today's deliberately perishable art, e.g., Christo's wrappings, permanence seems no longer to be a criterion. Granted fashion differs from other arts in that most of us can participate in creating it, in which case it becomes the art of self-expression.

It can, however, be costly. It takes virtually no money to write a poem or make a drawing. But to dress well, unless you make your own clothes, takes money. Hence modern fashion has bifurcated. For the wealthy, there remain the designers producing expensive haute couture. For the rest, there is something new.

Casual wear, leisure clothes and footgear, have taken over much of the clothing trade. Not long ago there was no such thing as Gap, Benneton, Reebok, Banana Republic, Eddie Bauer, and the countless rest. There you can acquire the latest in tight-clinging or loose-fitting, mainly sport-derived clothes, and an endless variety of footwear that looks like a cross between the old sneakers and the Tower of Babel. Until recently few of these clothes, and none of these shoes, would have passed muster in offices and other respectable surroundings; now they are practically everywhere. Symbolically, Nike is opening a super-store in Manhattan next door to Tiffany's. And all over America's cities you can see women dressed properly, even elegantly, going about with Nikes on their feet.

And not just women: fashion designers themselves appear in public in clothes only the riff-raff would be presumed to favor. I can remember how elegant the great fashion designers of yesteryear were -- men like Pierre Balmain and Jean Patou, to name but two, were always fashion plates, as is Oscar de la Renta today. But I remember my disappointment on meeting Nino Cerrutti sloppily dressed. Since then something has happened. I first noticed it with the brilliant designer Karl Lagerfeld, who looked to me like a cat-burglar in all-black casual wear and with a pony tail dependent from his boding head. The look seemed all right while he was designing trendy clothes for Chloe; but later, at Chanel? Yet that was nothing compared to the downright malevolent and thuggish look affected by Gianni Versace. And Jean-Paul Gaultier, in his skirts, might frighten little children.

How to explain all this? The casual look of the last decades has something to do with the success of the beatniks, something with the latter-day homosexual camp (as opposed to earlier homosexual chic), but mostly with today's trend toward what I'd call diurnal dishabille. At the recent MTV awards, the audience, as Bob Morris reported in the New York Times, consisted of ''honchos and junior honchos, some looking as if they couldn't bother to dress, others looking as if they couldn't bother to do anything else.'' Yet is there really much difference between those extremes? There are clothes from, say, Calvin Klein, Norma Kamali, Donna Karan, Ralph Lauren, and Tommy Hilfiger about which one can't be at all sure which social class they cater to. Some people may consider this democratic and good; I myself have doubts.

Take John Galliano, chief designer at Givenchy, ''born [35 years ago] in Gibraltar, the son of a Spanish plumber who migrated to England in 1966.'' The Times reporter (Mitchell Owens) describes the heir to the impeccable Baron de Givenchy, himself heir to Balenciaga (probably the greatest of them all), as an ''amiable rock-and-roll hipster -- short, dark, wiry, near-constant grin splitting his face from one pierced ear to the other.'' On a given day, he was ''dressed like a cross between a Kabuki warrior and a silent-movie pirate: hoop earrings, billowy Japanese trousers patterned with giant flowers, a tight shirt open to frame a tanned expanse of a hairy chest. Around the waist was a wide snakeskin belt, and each wrist jangled with heavy silver charm bracelets.'' No wonder that he never met Hubert de Givenchy, who was still occupying another part of the establishment.

Is it a matter of social class? Not really. Cristobal Balenciaga, ''the Master,'' was the son of a sailor and a seamstress in the fishing village of Guetaria on the Cantabrian coast. But look at his 1940 portrait photograph by Man Ray and set that beside the verbal portrait of Galliano. Could elegance be merely something a bunch of clever hipsters make for other people, the way someone might deal in garden furniture without owning a garden?

The pirate look is, of course, camp; but the second-story-man look is more minimalism than affectation. Clearly, if minimalism flourishes in music, in the fine arts, to an extent even in literature, fashion will also be affected. Arguably the greatest fashion statement of our century is the blue jeans. Although they go back to a Genoa (in French, G - nes) of long ago, where sailors wore something like them in a fabric imported from Nimes (de Nimes), it was not until Levi Strauss in the California gold-mining days dyed denim indigo that Levi's became the popular and prestigious thing they have become.

Prestigious? Yes, in the Third World, where young men and women are crazy about American jeans. The now-forgotten Soviet novelist Panteleymon Romanov wrote a once-famous novel, For Three Pairs of Silk Stockings -- meaning that any Russian woman of the early Revolutionary period could be had for them. Throughout much of our century in many less-privileged lands, it is for a pair of American Levi's that girls and boys could be bedded. And as if that weren't enough for the still extant house of Levi Strauss to have inflicted on us, it also spawned Claude Levi-Strauss, the father of structuralism. But I digress.

My point is that we live in a dressed-down age. This makes clothes, which had grown inordinately expensive, more generally affordable, and, more important, allows the populism to which our democracy has devolved to inscribe itself on fashion. Fast clothes for people who eat fast food. Of the elaborate neck gear that Beau Brummel devised, his biographer, Hubert Cole, tells us, ''It was, even for the master, a difficult perfection to achieve, and the story soon got around of his valet descending the stairs with an armful of discarded ties, remarking 'our failures!' to the ascending visitors.'' The perfectly tied ''neck-cloth,'' long toiled over until the artist got it just right, is not for our times, egad!

EVEN so, fashion persists as an icon, a talisman, an earnest of our superiority to others. There have always been fashion items that, as it were, exalted their wearers. Lalique jewelry, a Sulka dressing gown (don't call it a robe!), a Fendi fur, Gucci loafers, Louis Vuitton luggage -- to name only some famous status symbols. These objects need not even be beautiful; they need only be genuine. I recall the novelist and fashion writer Alison Lurie remarking that everyone knows what the letters LV (the Louis Vuitton logo) stand for: they stand for ugly. I am sure that some who buy the stuff secretly agree, but you cannot argue with a status symbol.

Fashion is not trivial. Consider only the attention so many great writers paid it. Proust foremost. Consider that the perhaps greatest modern poet, Stephane Mallarme, edited and, under various pseudonyms, almost singlehandedly wrote the fashion journal La dernicre Mode. Consider the praise Shakespeare lavished on the Prince of Denmark: ''The glass of fashion and the mould of form.''

Fashion replicates the trajectory of poetry, as the great Swiss historian Jacob Burckhardt characterized it in his Weltgeschichtliche Betrachtungen (I translate): ''A turn from the necessary to the pleasurable, from the common national to the individual, from the paucity of types to the endlessly varied.'' It emulates history itself as it swirls in a Vicoesque spiral toward reiteration in renewed forms, as the barebreasted fashions of ancient Egypt return as the topless bathing suit of Rudi Gernreich and, nowadays, the ever more protruding breasts from high-fashion dresses.

Above all, fashion reflects bi-partisan politics in its bipolarity as it swings back and forth between opposite extremes. And not just successively, but also simultaneously. In Costume on the Stage: 1600 - 1940, Diana de Marly observes, ''There is always an overlap, and never a sharp division or precise date when one style comes in and another goes out.'' George Melly, in Revolt into Style, provides an excellent account of how London's fashion-conscious Mods and Teddy Boys duked it out with the Rockers and Skinheads, the Mods ''not afraid of looking pretty,'' the Skinheads ''aim[ing] at a hideous anonymity . . . caricatur[ing] their proletarian lack of ambition.'' An in-depth study of the history of fashion must reflect the history of culture, politics, economics, and social trends -- indeed the history of history.

The grandest disagreements are between leading designers. Nettie Rosenstein said, ''It's what you leave off a dress that makes it smart.'' Norman Hartnell, however, pronounced, ''I despise simplicity. It is the negation of what is beautiful.'' Defending the natural, Coco Chanel speculated, ''A woman is closest to being naked when she is well dressed.'' Not so Christian Dior: ''My dream is to save [women] from nature.'' Pierre Cardin fumed, ''The jean! The jean is a destructor! It is a dictator! It is destroying creativity. The jean must be stopped!'' But Yves Saint Laurent disagreed, ''I wish I had invented blue jeans. They have expression, modesty, sex appeal, simplicity -- all I hope for in my clothes.'' The head spins -- like the wheel of fashion on which we are racked.

Oscar Wilde, always a fashion plate -- albeit an eccentric one --has his Lord Goring pronounce, ''Fashion is what one wears oneself. What is unfashionable is what other people wear.'' Elsewhere, Wilde muses, ''Fashion is a form of ugliness that we have to alter every six months.'' This sardonic relativism does not recommend itself to my way of thinking. Each one of us, to be sure, must decide for himself what fashion is. Nevertheless, it is the charm of new designs rather than their ugliness that induces alterations. Perhaps not every six months, but before boredom sets in.

Finally, to those who deny the social significance of fashion, we can always retort with Chamfort, ''Change in fashion is the tax that the industry of the poor levies on the vanity of the rich.'' Bear in mind: fashion is not only Courrcges and Ungaro, Scaasi and Bill Blass; it is also the the great anonymous multitude of workers who stitch away at it and earn a living. That is the stitch that, in time, saves nine times nine million lives.