Boogie Nights takes us on a voyage through the back streets of the late 1970s and early '80s. Eddie changes his name to Dirk Diggler. And together with co-stars Reed Rothchild (John C. Reilly), Amber and Rollergirl, Eddie becomes the toast of the adult film industry. Action clips from a series of his films look like bad Starsky and Hutch. (Yes, I know that's redundant.) In them, Eddie stars as a secret agent named Brock Landers who beats up bad guys and saves the world as he beds all the beauties along the way. Interesting, isn't it, how close that description comes to capturing the long James Bond series. Is it just a matter of where you put the camera when you shoot the sex scenes?

Eddie and his pals get rich. Eddie buys himself a red Corvette, a fancy pad and furnishings that make us hold our sides laughing. Before we get too smug, though, we need to remember what Graceland looks like. And Elvis is a god, isn't he? As with Elvis, things go bad after a while. Too little discipline, too much dope. Elvis turned his head, and his audience was stolen by the Beatles and the Rolling Stones. Eddie gets sloppy, and pretty soon the naked guy in front of the camera goes by the name of John Doe (Jonathon Quint). In fleshpot Hollywood, as in the mainstream, what goes up must come down.

There's so darn much to like about this movie. It is notable, first of all, for its firm determination to avoid being judgmental. Boogie Nights is neither a champion of the pornographic film industry nor its self-righteous accuser. The characters the film situates in the industry are mostly damaged. Eddie comes from a horrible lower-middle-class home with a vicious mother and an impotent father. Rollergirl is a high-school dropout. Amber is a divorced mother who has lost a custody battle with her cold ex-husband. A black performer named Buck Swope (Don Cheadle) has turned to porn because of the dearth of decent roles for black actors. In one fashion or another, all these folks are looking for a family. Some troubled souls in our society turn to religious cults; these people find an oddly nurturing community in the adult film industry.

But just as Anderson probes the scandalous to find the human dimension at its core, he refuses to romanticize and, in that manner, to patronize his characters. Eddie is an innocent (his last name isn't Adams by accident). And he's actually quite nice, as illustrated by his relationship with Scotty (Philip Seymour Hoffman), the homosexual sound man. But Eddie's not exactly the brightest bulb in the lamp. In the film's sober denouement, we can see the extent to which life has reduced him to his own sexual member. Amber really does care for Eddie, and there's no question that her maternal instincts are both strong and genuine. But she's a contemptible jerk for turning Eddie on to cocaine. Jack readily plays father to Eddie and Rollergirl both, but his dreams of genuine artistic achievement are laughable. He means what he says, but his coarse exegesis on art porn is a howler. When Jack studies footage of his latest skinflick and waxes ecstatic about what he has wrought, we can't help but think of his nursery-rhyme namesake's penchant for self-congratulation. And, in addition, Anderson recognizes that the adult film business is a magnet for legitimate creeps. The man who bankrolls Jack's films is busted for kiddie porn, something Anderson obviously does condemn.

Anderson's script is endlessly inventive and far more interested in complexity of characterization than in forthrightness of theme. But he has points to make. One can't help but reflect that the various debauches of the '70s gave way to the cultural backlash of Reaganism in the '80s. The character of Little Bill (William Macy) may be seen as an emblem of this transformation. He works in the pornographic film industry, but he's incensed at the sexual licentiousness of his wife (real life porn star Nina Hartley). His wife's thoughtless behavior is wrong, but Little Bill's responding violence on New Year's Eve 1979 is not an appropriate response.

Elsewhere, issues such as race bubble up with great subtlety. Both Buck and the black female star, Becky Barnett (Nicole Ari Parker), seem to have arrived on the porn scene for slightly different reasons than their white counterparts, and both try to escape to notably unglamorous places. Becky moves off to Bakersfield with a man who manages an auto parts store. Buck strives to realize a dream of owning his own audio equipment outlet. Moreover, it is fascinating to note that the problems the picture's characters encounter are not the direct by-products of having sex on film. AIDS is never introduced, for instance, nor are any other sexually transmitted diseases. Neither is sexual jealousy among the performers ever a problem. Rather, trouble stems from that traditional host of vices, including greed, vanity, faithlessness and various forms of excess. It is clear that Anderson is not out to automatically censure people who appear in and make sexually explicit films, but he is ready to condemn drug abuse, infidelity and violence.

Boogie Nights' dialogue recalls Kevin Smith's Clerks and Quentin Tarantino's Pulp Fiction. It is casually explicit and riotously funny. In one segment, Eddie drives us into the aisle with laughter as he holds forth on pornography and the lessons of history. And Reed splits our sides with his ridiculous self-assurance as he contemplates what life would be like if he weren't a porn star: "I'd just have sex on my own time."