THE PROBLEM of what to wear began with the fig leaf.

Dress as the object of moral wrath followed soon after (Isaiah 3: 16-24). The latest trend, seen in the two books under review, is to study the significance of clothes, what they show and tell about people.

Kennedy Fraser's The Fashionable Mind, a gathering of her columns from The New Yorker over the past decade, takes fashion seriously, but not solemnly. When she describes British fashion as "often extraordinarily and meticulously refined" but as always retaining "a touch of affectionate humor," she characterizes her own feeling for clothes. She is fascinated by fashion, but wary of its trivial, transitory side; her tone is ironic, bemused, deadpan. She questions Charles Revson, "the philosopher-king of the cosmetics world," about makeup. "Remembering the Revson faith in eyes, I asked him about the future of false eyelashes." The scene that follows--he peers at her eyes and recommends Moon Drops mascara, which she is wearing--is amiably satiric.

Fraser is tentative about defining fashion, as opposed to the clothes worn by most people at any time. She distinguishes cleanly between style, good taste, and elegance. Her heart is with style, which is "individualistic, aristocratic, and reckless." It is "more akin to a philosophy" and "closer to an art" than "its humble relative, good taste," which is bourgeois, concerns "broad, lifetime progress, and never makes mistakes." One need not be fashion conscious or up on celebrities to find her analysis of style arresting. Without pretentiousness, without straining, Fraser links her embodiment of style, Bianca Jagger, to Dandyism. Baudelaire, she speculates, would have seen in her what the dandy represented to him, "the best kind of human pride . . . the urge to fight and destroy triviality."

Fraser's essays interpret various social changes. Fashion photography has moved from the portrayal of models in dreamlike isolated elegance to showing them in motion, as if in real life. The common acceptance of nudity on European beaches has led to new manners, and sunglasses have become "modesty's last frontier." Her reports on shopping (from boutiques to electronics), body fitness, the new agelessness, hats, and executive women tell us how we live now.

The book also chronicles the fluctuating careers of designers and the accelerating fashion cycles from the end of the miniskirt through the revivals of fashions from past decades and so to the impasse of today. Coming to this country from England after an Oxford education, Fraser took over The New Yorker column in 1970, the year American women rebelled against fashion decrees. Thereafter, fashion in the old sense of rules and authority vanished. For her, the '60s was "the last period when fashion spoke with a kind of common voice." Novelty in fashion, though artificially kept alive by the trade and its publicists, ceased to be important.

The title essay, "The Fashionable Mind," concerns the infiltration of cultural and social life generally by fashion in the guise of trendiness, surfaces, and appearance. This piece is too abstract to be effective social criticism, but the best essays, including those on the British and French fashion worlds and on the Spanish designer Balenciaga, are remarkable for their esthetic sensitivity, historical grasp, and solid information.

Fraser has a novelist's eye for the sharp, telling detail and a flair for capturing the mood of time and place: Fifth Avenue on a summer's stroll in 1971; denim as a texture and an evasion of fashion in SoHo lofts where former SDS members take up the art of wok cuisine; the appalling crush at the fall collections in Paris where "even as a professional fashion woman elbows another in the ribs, she narrows her eyes to take in the details of her victim's cunningly draped Parisian shawl."

This is a special book. Fraser, who never talks down, has a voice of her own.

The same cannot be said of Alison Lurie. The Language of Clothes, her first book of nonfiction, is a babel. Only once in a while do we make out the clear, bright voice heard in The War Between the Tates and sometimes in her five other novels.

The New York Review of Books published two parts of The Language of Clothes and Roland Barthes is invoked in the second paragraph, but our first impression that Lurie is pioneering a sociological or semiotic study of clothes proves wrong. Laying down the grammatical rules of dress, she hasn't bothered much about the rules of evidence, logic, argument, or the English language.

There are footnotes and a bibliography and baffling references to "informants," including "my friend the lady executive," "a former journalist," and "a journalist of my acquaintance," who come forward to give testimony like actors in a TV commercial. As far as I can make out, the "informants" are the friends Lurie thanks in the preface, and her research consisted of attending national conventions where she observed regional dress.

The pseudo-scientific objectivity would have been only a blemish, if Lurie had succeeded otherwise on the strength of her own insights. As it is, she rarely produces a pleasing shock of recognition or of novelty. New sections are introduced with primer-like statements such as "Black, the reverse of white, is the color of night and darkness."

Other generalizations are untrue to experience or prove, as George Orwell said, that the "slovenliness of our language makes it easier for us to have foolish thoughts." On the subject of "vulgar words" in dress, Lurie writes: "A torn unbuttoned shirt, or wildly (sic) uncombed hair, can signify strong emotions: passion, grief, rage, despair." They can, but except in melodrama, or complexly in Hamlet, do they usually? Playing golf in jogging clothes or riding a bicycle in a bathing suit on a hot day would cost a fashionable person "a drastic loss of prestige." In some fashionable circles such behavior would provoke no comment, or might even be thought rather stylish. Women who wear blurred abstract prints are inclined to be "somewhat out of touch with the natural world." Lurie must be unfamiliar with rural Virginia. For examples of a certain type of conservative dress, Lurie uses "Young Republican supporters" (junior Young Republicans?) and "certain civil engineers" (certain graduates of MIT?).

The slipperiness of fact and phrasing is pervasive. Tattoos are "difficult to remove if you enter another stratum of society." Apparently easy enough otherwise. "If maximum fertility is to be achieved, we must select members of the opposite sex rather than our own to make love to." As a passing comment on the erotic function of clothes, this statement raises unintended questions on population growth. White for weddings became conventional not 50 years ago, as Lurie has it, but more than 150. Red may be a hazard to health if we're to believe Lurie: "physiologically, the sight of this color causes a rise in blood pressure, respiration rate and heartbeat." That Southern women tend towards "bows, ruffles, lace and embroidery" and consider suntans unfashionable sounds to me like Scarlett O'Hara, not the South today.

Fact and fiction are blurred. One of Lurie's special twists is to use literary sources for examples, but it doesn't work. As evidence for what can happen to an adolescent who dresses to look older than her age, Lurie refers to the trouble Carson McCullers' Frankie in A Member of the Wedding gets into. This is on the level of using Lady Macbeth as a warning to ambitious wives.

The helpfulness of Lurie's tips on dressing for success in sexual and business affairs may be judged by her warning that the "clerk who dresses like his boss is apt to be regarded by other clerks as a cold fish or an ass-kisser." A secretary who makes the same mistake "is seen as snotty and pretentious." The vulgarity of phrasing is typical of Lurie's style. The hard-boiled "with it" tone she has adopted taints even the better parts of the book.

The good things include amusing bits and pieces on sailor suit fashions for children, the cycle of ideal beauty from Victorian sylph to Edwardian grande dame, the symbolism of stripes and dots. The cartoons, advertisements, and photographs assembled by Doris Palca to illustrate the book are diverting. Despite such lighter moments, the rewards for working through the jumble of Lurie's book are too slight for the labor involved.