A kind of queasiness prevails in the way men and women relate to each other nowadays. After the no-holds-barred sensualism and the extempore eroticism of the recent past, the search for a new code of manners takes place on shifting sands, in a dance composed entirely of false steps. The movies being what they are (no greater praise in Hollywood than that someone is "close to the audience"), you can see the struggle up on the screen where characters grope for a middle ground between promiscuity and marriage. And, in a parallel, the fight goes on in the way we classify those movies, and decide what is "acceptable" and what is not: the ratings system.

In the eight years that the Motion Picture Association of America (MPAA) has polled moviegoing audiences on the subject, the division of movies into G, PG, R and X has never been more popular: 67 percent of adults with children find ratings "very or fairly useful," up from 59 percent in 1977. The National Association of Theater Owners (NATO) estimates that 85 percent of its members subscribe to, and enforce, the advisories. But if people generally feel that some ratings are necessary, they're less likely to agree as to what kind of standards we need, or which movies should fit where.

The question of standards led to reform earlier this year, when the MPAA introduced the first new category since the ratings were inaugurated in 1968. PG-13, which cautions parents about the suitability of certain films for young children, arose out of controversy over "Gremlins" and "Indiana Jones and the Temple of Doom."

Jack Valenti, president of the MPAA and the inventor of the ratings system, opposed PG-13, and he may have been right; PG-13 has unleashed centrifugal forces within the R category that threaten to explode the whole house of cards. Movies that are barely R are now reedited to qualify for PG-13 (in "Dreamscape," for example, the few shots of a partially nude Kate Capshaw were excised before the film was released); at the other extreme, violent and sexually explicit films are straining the border between R and X. Brian De Palma claims to have censored himself in the production of "Body Double," and the "Crimes of Passion" showing now in See ESSAY, Gx, Col. x American theaters is considerably different from the version screening around the world.

Valenti emphasizes that the ratings are advisory. "If anyone cuts anything, it's because they perceive the rating to be economically disadvantageous. That perception is theirs, not ours. No one is forced to delete or change anything." But such hand-washing is somewhat disingenuous. Many exhibitors have a blanket policy against showing an X film, pornographic or not (such as the giant General Cinema Corp., with more than 1,000 screens); even those exhibitors that don't automatically reject X pictures are leery of them. "We're in the community, and I hate to meet someone in my health club who says, 'What, are you showing porn these days?' " says Ted Pedas of Washington's Circle Theaters, who has historically drawn the line somewhere between "Last Tango in Paris" (which he showed) and "Bolero" (which he turned down).

Television stations won't advertise an X movie; many newspapers have restrictions. And the major studios (all of which are members of the MPAA) won't release an X; they contractually specify that each director deliver a rating no more restrictive than R.

Economic forces, in other words, have conspired to make the idea of a legitimate X picture, formerly not uncommon ("A Clockwork Orange," "Midnight Cowboy," which won an Academy Award for Best Picture in 1969, and "Last Tango" were all originally X releases), almost impossible. Filmmakers, predictably, cry censorship. "I think it should be purely advisory," says De Palma. "Let parents decide. When I was a kid, my parents wouldn't let me go to certain kinds of movies. My mother said, 'You're not going to see that picture. Forget it!' And that was it."

Ken Russell, the director of "Crimes of Passion," is particularly bitter. Besides some oriental erotic art and some drawings by Aubrey Beardsley, the ratings board made him cut two sequences, important to his characters' motivation, before it would grant him an R. In one, the heroine, a prostitute with a double life named China Blue, abuses a policeman with his own nightstick; in the other, the play of shadows on the wall, reflecting lovemaking between the hero and heroine, was intended to demonstrate how they relate to each other sexually -- without it, the attraction between these two dissimilar people is simply puzzling.

"The sadomasochistic scene with the policeman was a turning point in her psychological makeup," Russell says. "A gradual realization that you couldn't separate the two, you couldn't separate your life from your sexual act. It was very powerful, one of the most powerful scenes I've ever shot. And the shadow scene, it was very beautiful actually, but the ratings board only wanted one sexual position, they didn't want half a dozen.

"This is obviously a serious film," Russell complains. "If I wanted to make a porn film, I'd make a porn film as easy as anything. It's as though this damn certificate is an award of merit, and if you don't get it, you're blackballed. Go to the bottom of the class, wash your hands and stand in the corner. It's not as if it's that outrageous -- I see stuff similar on British television almost every week. It's total madness . . . dictating what people can see and can't see."

Such protestations are a little overheated. There's much that is laudable about the film industry's attempt to police itself, and to protect children from images that could disturb them. More importantly, the ratings system protects the filmmakers themselves -- it effectively supersedes the agencies of local censorship that would probably be much more restrictive, particularly in a time when the feminist left has allied with the religious right (for both of whom films like "Body Double" and "Crimes of Passion" are pornographic) in authoring local antipornography legislation under the incongruous banner of civil rights.

"If there were no ratings system," Valenti says, "there would be hundreds of municipal, state and local boards that would perform the same function. That would be chaos in the marketplace. You're going to have to edit a film a hundred times. Now we have a single standard, albeit flawed, albeit subjective."

For Russell, the answer is that "there should be different grades of adult films. We shouldn't all be lumped together." Some have suggested a new category -- "A" for adult, including films that, while unsuitable for those under 18, were also not pornography.

"I would be vigorously opposed to it," says Valenti, who says newspapers, television, exhibitors and the studios would have the same reaction no matter what the alphabetic designation. "A category becomes the same color as the pictures that inhabit that category," he says. As the R category has expanded (even the bowdlerized "Crimes of Passion" is far racier than the X-rated "Midnight Cowboy"), X has become a badge of pornography. More to the point, Valenti says, dividing films into A and X would essentially involve the MPAA in deciding what is obscene and what isn't, a task at which even the Supreme Court has failed; separating adult films into X and A could embroil the MPAA in lawsuits brought by producers given an X.

What Valenti identifies as the strength of the system -- that it is a single, central, simple code -- is also its chief problem. People want more than a ukase of good taste dictated from on high. The latest craze is a system of "explanations," not unlike the parents' guide published by TV Guide and many newspapers (not just "rated R," but "rated R for sexual situations," or "strong language," or "violence"). During their recent convention, NATO considered recommending a division of PG-13 into "PG-13: Violence" and "PG-13: Sex" before ultimately deciding to leave the category alone for a while.

But recasting the code as ratings with explanations, or just explanations, or ratings balkanized into subratings (like A and PG-13), would only dress it up in the Emperor's New Clothes. As Valenti points out, a born-again Christian man from East Texas, unflustered by a movie's murder of a woman, might be profoundly upset if a character took the Lord's name in vain, while a woman in Washington might have quite the opposite reaction. In this context, what would "R: mild language, violence" really mean? The essential problem remains -- whatever you call it, any code will founder on the absence of consensus. Each one of us wants standards, but we want them to be our standards; we yearn for tradition, but can't go home again.

As you watch recent movies with sexual themes, you see men and women grappling with the same problem; marriage is their private version of the ratings code, a way to differentiate acceptable from unacceptable sex, to carve out a sphere of propriety amidst moral chaos. The idea of tradition looks good again, but today, when we finally get down to reviving a taboo like extramarital sex, it seems to threaten us.

The shift in sexual attitudes has appeared markedly in the radical revision of the teen sex comedy. "No Small Affair" gives us the leering, rampant promiscuity that has become familiar in the genre. What's new is that the hero rejects this world. When a prostitute hired for his brother's bachelor party offers the hero a freebie, he asks for a hug instead.

Like "The Joy of Sex," "The Wild Life" and "Where the Boys Are," "No Small Affair" uses free sex to titillate the audience, but makes it clear that it's something to disapprove of. In these movies, the problem isn't that the heroes and heroines can't find sexual partners -- sex offers itself up in outrageous profusion. What they want is old-fashioned courtship: flowers, hand-holding, the first tentative kiss and so forth.

The male menopause sex farce shares the same premise. In "The Woman in Red," Gene Wilder plays an ad executive bored with his marriage; a beautiful fashion model is enough to set him falling off a horse (three times), wearing funny clothes and throwing tantrums in his bedroom. Predictably, he ends up recognizing the shallowness of his infatuation and returns to his wife. The same thing happens in "Thief of Hearts," which might be called a female premenopausal thriller. A woman stuck in a sexless marriage to a workaholic writer fantasizes about a mysterious lover who, sure enough, arrives on cue with his arsenal of pleasure. Does she leave her husband? Of course not!

From the way the eponymous thief squires his prey around San Francisco harbor in his sailboat, plying her with champagne, you think you're watching a full-length screen version of one of those cologne ads. By making sexual fantasy seem so trivial -- "The Woman in Red's" fantasy of a glossy goddess springing from the page belongs not to middle age but to adolescence -- these movies make the decision to opt for commitment seem a lot easier than anyone thinks it is.

"Tightrope" offers a more sophisticated rejection of the sexual revolution; but in a way similar to "A Woman in Red," "Tightrope" stacks the deck. As zaftig, naughty harlots hurl themselves at the hero, played by Clint Eastwood, his face hardens into a furrowed, impassive rictus -- these women look like they're climbing Mount Rushmore. It seems easy for him to opt for marriage -- he may be perverse, but he doesn't seem to enjoy it very much. The problem with "Crimes of Passion" is that Ken Russell enjoys it too much. His prostitute-heroine finds salvation in a mutually supportive marriage founded on old-fashioned, healthy sex. But paradoxically, Russell makes you resent commitment; you found his heroine more entertaining when she was fit to be committed.

"Falling in Love" tackles the question by avoiding it altogether. Robert De Niro and Meryl Streep play two married people who are excited by their illicit trysts; yet, as solid family types, they wouldn't like each other half so much if they thought the other was anything but faithful. The problem is that screenwriter Michael Cristofer never lets them talk about this moral quandary; in fact, he doesn't let them talk about anything at all. The sexual element of their affair is downplayed -- Streep and De Niro get along like old friends, not new lovers -- and when the Moment arrives, Streep decides to call a halt before she's even got her slip off. Cristofer solves the problem of sexual freedom within marriage by just leaving it out -- the movie is one giant ellipsis.

Then there is "Choose Me," one of the first movies to capture the will-o'-the-wisp of sexual style in the '80s. Lesley Ann Warren plays the bartender/owner of Eve's Lounge; the loving circles the camera draws around her become a metaphor for her own self-involvement. Unhappy with her revolving-door love life, she's also incapable of intimacy; the solution comes in the person of Mickey (Keith Carradine), a pathological liar with a re'sume' to match. When Eve has trouble with true love, it's because she associates it with the naive, idealized self that she preserves beneath the luscious, good-time girl personality that she's created. She has disconnected what she is from what she has become, so connecting with other people becomes that much harder.

In the America of "Choose Me," people are unhappy with carefree sex and egotism, but they can't just discard them -- they've become part of the national character. The answer, for director Alan Rudolph, is not to exhume tradition, but to make a kind of joke of it; Mickey asks every woman he meets to marry him. Nothing is "true" in "Choose Me" (it turns out Mickey really was all the things he claims to be), least of all "true love" -- Mickey proposes to every woman he kisses. But when they say yes, he's faithful to them. For Rudolph, constancy in sexual relations is an act of absurd will; in the '80s, even marriage is an occasion for irony. Irony makes taboos porous enough to be livable; it's too bad we can't build irony into the ratings system.