The Darkness of the Damned : THE DEMON <i> by Hubert Selby Jr. (Marion Boyars: $19.95; 312 pp.)</i> : THE ROOM <i> by Hubert Selby Jr. (Marion Boyars: $19.95; 288 pp.) </i>

Hung up in echoing patterns of obsession, novelist Hubert Selby’s heroes are forever trying to beat the system but find themselves doomed to a loser’s world. Driven to escape a fatal confinement in material hells of New York City and in complex hells of Being, they mount violent, dark revolts, but are continually pulled back into the damned condition from which they started--discovering, like Marlowe’s Dr. Faustus, that “where we are is hell, / And where hell is we must ever be.”

In Selby’s world of urban lost souls, individual identity is as much beside the point as it is for John Bunyan’s “Everyman” or Samuel Beckett’s “Unnameable.” Suffering through endless “routines” of abjection as ultimate proof of the humility of a dehumanized humanity’s humility before a nonexistent God, his protagonists drift in a fluid, hallucinatory haze of drive and phobia, lust and revulsion, sin and retribution, necessary crime and inevitable punishment.

Headlong, stark and arresting, Selby’s books have the energy, intensity and pain of alienated singular vision and an inexorable momentum of horror that is at once hypnotic and almost too much to bear.

Selby is a self-taught writer who went from P.S. 102 in Brooklyn to the Merchant Marine to a long literary apprenticeship, working at odd jobs while moonlighting as a storyteller. His first book, “Last Exit to Brooklyn,” won some fame--and, due to its raw content, more notoriety--in the mid-1960s.

His three novels of the following decade--”The Room” and “The Demon” (first published in 1971 and 1976, respectively) as well as “Requiem for a Dream”--undeservedly received far less notice. Since then, he has published only one book, “The Song of the Silent Snow,” a collection of short stories to which readers may wish to turn to find early rehearsals of the two novels here under review.

In a significant sense, Selby’s entire work comprises one overlapping tale, with interchangeable settings and a single central figure who, when given a name at all, always is called Harry. In “Last Exit,” he is Harry Black, a union shop steward. In “The Demon,” an almost perfect novel that may well be the writer’s finest achievement, he is Harry White.

White is an ambitious, upwardly mobile young corporate executive with the sex drive of a satyr, the inner tension of a tightly coiled spring and a sleepwalker’s lack of self-knowledge. The latter deficiency, a tragic constant in Selby’s scheme of the doomed, triggers a geometric progression toward despair whose finely calibrated gradations the novelist charts with terrifying, Dantesque precision. Harry may not know it, but each step in his climb up the success ladder, and each mechanical surrender to “the demon that was welling up inside him,” adds to the burden of inarticulate grief, guilt and shame that will become his downfall. And the higher he climbs, the steeper will be his vertiginous tumble into the inferno.

For Harry White, an automaton-like pursuit of sexual release with woman after woman is the only way of appeasing the inner demon. Sex for Harry is not passion but a convulsive compulsion, a wallowing in defilement that defers but does not remove a crushing weight of meaninglessness in his life. Each new conquest brings temporary relief that soon yields in turn to new cycles of tension, self-conflict and pain. An “ideal” marriage to a beautiful, loving wife, an executive vice presidency of his firm, a luxurious home in the suburbs, all the trappings of fortune are but fuel to Harry’s insatiable demon.

When the fall comes, Harry at first does a good job of concealment. A crack-up episode over lunch at the Banker’s Club leads to a hospital visit, where, to his secret dismay, the doctors are able to find no physical explanation of his erratic behavior--”no tumor. . . . Nothing. Just him.” But soon his “night visits to hell” are becoming more and more desperate, his battles with the demon less and less successful. He turns from casual sex to petty theft to gratuitous murder, eventually finding himself immersed beyond all extrication in “the huge cesspool that he felt he was, and could not get away from.”

With Selby’s careful prose taking on the accelerating force of catastrophe, Harry meets his fate in scenes of orgiastic violence and sacrificial self-immolation, an Easter Sunday murder of the Cardinal of New York on the altar of St. Patrick’s Cathedral followed by a final suicidal plunge into the vortex of oblivion.

Harry White’s spasmodic attempt to penetrate the void of being, to force meaning out of the pointlessness of his life, brings him to self-revelation at last. As he dies, all the evasion and avoidance and “games” now swept away, he finds “the truth of his life suddenly thrust in front of him,” his timetables of success obliterated in a timelessness of vision.

It is out of a like timelessness that Selby’s companion novel, “The Room,” begins. A nameless prisoner, charged with a crime he may or may not have committed, speaks to us from his confinement in the remand cell where he is being held pending trial. His telling-over of the repetitive minutiae of abjection, his reveries exposing the repressed traumas of his childhood, the sexual warpings and stuntings of his adolescence, and his violent, imaginary revenges against his captors, make up a canticle of pain that reiterates the central truth of Selby’s dark vision: The interior hell and its torments are at once the supreme proof of cosmic justice and of the absence of mercy from the world.

In Dante’s medieval conception, hell was located at the Earth’s core, and thus farthest from the sun, stars and planets by which human time is told. For Selby’s incarcerated hero, similarly, there is no time, only the unendurable weight of being--”it just seems to drag and drag and weigh a ton. And hang on you like a monkey. Like it’s going to suck the blood out of you. Or suck your guts out. . . .”

Selby is a seeker after the quality of mercy in an age ruled by the indifferent mechanics of quantity, a writer whose books defiantly refuse any such easy accommodation with the social order as is implied in the work of, say, John Updike; as Amiri Baraka once suggested, Selby’s pages are populated by “Americans no character in a John Updike novel would be happy to meet.”

At a time when the most successful fiction is that which provides reassuring distraction from the difficult truths of existence, it is easy to see how the acute and agonized moral vision of a writer like Selby may go ignored by--as culture critic Theodor Adorno once put it--”those who would like to sleep through the deluge that threatens them.” Selby’s works unleash the darkness of the deluge.