James Toback begins his searching, stimulating documentary "The Big Bang" with his sales pitch to a prospective producer. He tells him, more or less, that he knows how it all started. It came to him, he says, as he was standing out on the balcony of his hotel in Santa Monica.

How what started, the producer asks.

The cosmos, Toback says.

The cosmos?

Yeah, it started with the orgasmic explosion of God.

The orgasmic explosion of God?

Toback tells him that he wants to make a movie about it, and wants the picture to be about everything -- "God, love, sex, crime, madness, death."

Great, the producer says. Let me see the script.

Well, Toback responds, there is no script.

Okay, then, who's going to star in it, he asks.

Well, Toback says, there are no actors or stars, per se. Just people talking, all kinds of people.

So let me get this straight, the could-be producer says. You want me to put up money for a film with no script, no stars, just people talking?

Pause.

Yeah.

With that, "The Big Bang" commences, and it is just as the director promised -- a film about everything. Toback presents us with a collection of different types: an astronomer, a gangster, a basketball player, a jazz musician, a Holocaust survivor, a movie producer, a painter, a philosopher. Sitting across from them, the provoking interlocutor dressed in a black leather jacket poses the Big Questions: Is there such a thing as God? How did the universe begin? How do you define the "self"? Who are you?

The answers he gets vary in depth and interest. The Little Girl, Emma Astner, says the universe began first as dust, then there was a squirrel, then a dog, and her design is about as well formulated as anyone else's. Most of the interviewees, who were assembled in a mansion in Tenafly, N.J., seem slightly taken aback by the questions, and not merely the ones of a personal or sexual nature. Nobody, it seems, has given all this much thought, certainly not to the extent the director has.

But what Toback's subjects deliver, even if their answers aren't especially thrilling, are bits of themselves, their personalities, their experiences. Where the film is most specific, where it focuses on real biographical detail, is where it is most engaging. This, certainly, is no accident, though Toback slips his inquiries in delicately, somewhat under the veil of philosophical exploration. The group reflects a remarkable diversity of types and styles, and as the film goes along, it becomes a celebration of that variety and richness. The Boxer, Jose Torres, who was once the light-heavyweight champion, has a quiet, gentlemanly elegance as he talks about his fears of insanity and chaos. "That is the thing that scares me the most," he says.

By contrast, the Basketball Player, Darryl Dawkins, is all bravado and street-corner posturing. "I'm 6 feet 11 of steel and sex appeal," he says. Dawkins is one of the film's most vivid portraits, perhaps because his approach to life is so simple and direct. He is defined completely by his appetites. Asked how he would like to spend the rest of his life, he says, without hesitation, to get a yacht, put a couple of girls on it and cruise around the world. "You know, party. Drink champagne out of slippers, eat-away bathing suits, that kind of thing."

The Gangster, Tony Sirico, who is also a screen actor, is one of the documentary's most moving characters, especially when he talks about the woman he loved and left his wife and children for and who ultimately deserted him when he was sent to prison. "The first six months in the can, you didn't wanna know me. I was a dangerous, dangerous kid."

There's an emotional charge to others as well. The Mother, Missy Boyd, has the most wrenching moment, when she describes watching the car accident that killed her young daughter. The Filmmaker, Don Simpson, who produced "Top Gun" and "Days of Thunder," comes across as an intelligent, articulate man who's grown a hard shell of coarseness over a bruised, sensitive past. Only the testimony of the Survivor, Barbara Traub, seems intrusive, if only because we've heard these horrors recounted so many times before.

Toback, too, reveals himself in the process of asking his questions, poking fun, in his encounter with the Model (Sheila Kennedy), at his image as a lothario by lounging provocatively close to his attractive subject. In a sense, Toback, who also directed "Fingers" and "Exposed," is annotating his own driven, Dostoevskian sensibility. And his movies as well. Still, there's an airy lightness to the film, a conviviality that comes both from Barry Markowitz's soothing camera movements and from Toback's insistence on not pushing things too hard. As an interviewer, he's the last thing you'd expect him to be from his other films, relaxed and nurturing and almost blithe. Thinking deep thoughts seems to have mellowed him.

The Big Bang, at the Biograph, is rated R and contains some frank talk about sexual matters.