From a Glowing Campfire to a Bleak Street : Monologues: Spalding Gray and Eric Bogosian are skilled monologuists, but where one cultivates, the other detonates.

Spalding Gray one night, Eric Bogosian the next: What different ways these men inhabit a bare stage, and with what different demons.

Gray, with his air of the self-obsessed Yankee--Woody Allen as Ethan Frome--stoutly maintains that he cannot make things up, that he merely distills and describes what goes on around him. The events he leads us through may be real, but it would be disingenuous of us to overlook the skill that goes into shaping the trip.

Gray is an intellectual’s tale spinner from the tradition of flannel-shirted campfire storytellers. His night’s entertainment, which he calls “The Monster in a Box,” conducts us on a journey with a dozen rambling side trips and diversions; the feeling in the audience is that we’re there to listen. Laugh, perhaps, but most of all be held in the grip of the yarn.

We expect to be manipulated; actually part of the edge we may feel as he begins is wondering just how he’ll do it. Gray initially lulls us; then having done that, guides the storytelling as firmly as a practiced orchestra conductor. There are even music-like crashes of volume and tempo, followed by hushed passages of contrast.

Gray’s work has a great plus: It’s anti-high concept. For all of us in the grip of high concept’s punishing simplicity, in films, on television, an evening of such complexity that it can’t be described in one sentence is as seductive as a weekend in the country.

The superurban Bogosian, who becomes more than a dozen characters in turn, is as seductive as shrapnel. Lulling anyone is the last thing on his mind. His evening of “Sex, Drugs, Rock & Roll,” is, as he’s said, built around “what jerks men are,” and he has no lack of candidates, divided between street people and business people.

He opens with the insistent rap of a subway panhandler who knows guilt better than Freud and non sequiturs better than Dan Quayle. He offers the television talk-show appearance of an aging British rocker, his anti-drug message fuzzed by his fond memories of the high old bad days, his current cause, the Amazon Indians, only a trifle compromised by his own virulent--and unconscious--racism.

They are only part of a searing gallery, not laughable as much as pungently observed. It’s also one of the bleakest nights I can remember in the theater.

Bogosian is undeniably brilliant. Part of what makes him so glitteringly effective is that he’s as good an actor as he is; his whole body contorts with the fury roiling at the innards of every character and his connection to that frenzy is immediate. He is also absolutely exhausting, and--at least in my case--he throws a pall of sadness that hung on for days.

Who can live through this much desolation without one moment of compassion? Bogosian won’t allow it. He pulls the pin on one after another perfectly realized, self-deluding loser and watches, sardonically, as the shards fill the theater.

Listening as each character spewed his venom and was skewered by his own words, I kept wondering how the audience around me could be laughing at these hell-images. And they were; roaring at virtually every line.

The clue was in this audience’s age. Although more than a few in Gray’s audience were in their 20s, he also drew his share of baby boomers and even parents of baby boomers. Probably three-fourths of Bogosian’s audience was younger, a generation brought up on David Letterman and Eddie Murphy, and whose comic heroes include Andrew Dice Clay. They came expecting hip stand-up and the shock and assault that have become part of it.

In a way, the skills and values of that kind of stand-up desensitizes its audience to the pain of the characters they watch. When Spalding Gray brings up the suicide of his mother, the audience I was with dropped into hushed shock. Bogosian’s crowd, whose expectations of monologue were completely different, might well have laughed--they laughed at everything else.

In terms of monologue-through-character, Bogosian is more in Lily Tomlin’s school of multiple roles than in Gray’s self-focused single persona. (Gray does sketch in other characters, but only with lightning-quick strokes. The strokes with which he creates a meeting of CAA agents are as fast and nasty as paper cuts.)

It’s interesting to consider Bogosian’s work in the light of “The Search for Signs of Intelligent Life in the Universe.” Tomlin played women and men, from teen-age to grandparents; she attempted no less than the summation of an entire era; she dealt with street people and the handicapped in a way that was realistic but without either condescension or excesses of sentimentality. Most of all, the evening emanated from a tangible center of humanism. (Tomlin has at last finished fine-tuning the film version of “Intelligent Life;” and it should be out at last this year.)

Bogosian’s character’s are, superficially, different from one other, but at heart they’re virtually the same: know-nothings who either have power or yearn for it. Tyrants, hypocrites, coke-heads, superstuds, burn-outs and phonies, It’s not a very broad range. His time frame is no broader, the socially bleak present. And permeating everything is the feeling that Bogosian empathizes with none of his characters; he stands apart from them and above them.

This one-note, one-era narrowness, couched with such smugness, is part of what makes “Sex, Drugs, Rock & Roll” such a thin, malnourishing evening. (Bogosian himself has suggested that the variety is limiting; he’s retiring this show after its Mark Taper date.) Bogosian’s intentions may be as pure as any hellfire-and-brimstone preacher’s; he may be as dedicated as Gustave Dore, drawing the lineaments of hell so explicitly that readers would turn away from any temptation.

But for the pain it costs us to follow him on his unrelieved descent, we badly need some reassurance: a tiny ray of light somewhere, for people, for our society, for the planet. It isn’t forthcoming. The effect can make one feel simply punished and desolate.

It’s not simply that Gray deals with less shattering material so that it’s easier to feel warmer about his work. Gray goes into extremely dicey emotional areas; his mother’s death and the shock waves from that experience; his AIDS material, which puts the fear of AIDS in first-person perspective.

The real difference between the two solo performers is the way we leave the theater. With Bogosian we have been stunned witnesses to a series of detonations. With Gray we have shared a taste of the commonality of human experience.