Jack Vance is burly with a no-nonsense look about him. Physically, he suggests the aging private eye on the late show who wears suspenders and sleeps in his fedora. He is the slower-than-syrup pinch hitter creaking off the bench to bang out the hit you need, the beer-bellied brawler who gets slugged, grunts and keeps coming on.

He is also one of the truly important science-fiction writers of our day, having produced some 50 books over the last 30 years. Beginning in 1945, Vance stories stated showing up in science-fiction pulp magazines. His first novel, a paperback original, became available in 1950, but only to those cognoscenti whose reading material comes off drugstore racks. But somewhere along the way, Vance has picked up the prestigious Hugo, Nebula and Edgar awards for his work, a literary hat trick no one else has matched.

His name is one of the three or four that come up regularly when talking to aficionados of the genre. Yet outside of the inside world he has attracted about as much attention as an invisible man in a soundproof chamber. In a time when hype rather than quality of product sells books, Vance refuses to promote himself, adhering to the old-fashioned notion that story, not personality, is what the reader deserves. He didn't even want his picture on this page.

"A reader is not supposed to be aware that someone's written the story," Vance said. "He's supposed to be completely immersed, submerged in the environment."

The offbeat variety of jobs he had before he began writing full time---fruit picker, carpenter, miner in Sierra towns, jazz cornetist---make for the kind of dust-jacket promo material publicity agents spend hours concocting for the authors. In this case, it's all true.

Jack Vance is a native Californian who has lived in some part of the state for all of his 50 years. He was born in San Francisco, grew up in the Delta town of Brentwood, went to high school in L.A. and attended UC Berkeley where he began as a physics major, only to switch to journalism.

A dedicated reader from very early on, Vance dashed through children's literature with the ease of O. J. Simpson slicing through defensive lines in his prime. Tom Swift, the Oz books, Jules Verne, Edgar Rice Burroughs, Robert Chambers. The exotic and fantastic appealed to him from the word go.

By the time he was 12, he had constructed his own star chart. A decade later, while serving in the merchant marine, he was doing his scanning of the heavens on night watch in the Pacific and Atlantic Oceans.

Today, Vance quietly turns out work from a sprawling house perched high in the Oakland hills, a house he and his wife Norma have been rebuilding with their own hands since 1954 when they bought it as a cottage. Their son, John Jr., now growing out of his teens, live with them.

The same care with which Vance has poured concrete and cut moldings can be seen in his use of language. Armed with a vast vocabulary and a deep understanding of word origins, his prose more often than not is understated.

"The only good style is the style which no one notices," he said. Nevertheless, the Vancian imprimatur is unmistakable. One of his stories starts like this:

"The war party from Faide Keep moved eastward across the downs: a column of a hundred armored knights, five hundred foot soldiers, a train of wagons. In the lead rode Lord Faide, a tall man in his early maturity, spare and cat-like, with a sallow dyspeptic face. He sat in the ancestral car of the Faides, a boat-shaped vehicle floating two feet above the moss, and carried, in addition to his sword and dagger, his ancestral side weapons.

"An hour before sunset a pair of scouts came racing back to the column, their club-headed horses loping like dogs. Lord Faide braked the motion of his car. Behind him the Faide kinsman, the lesser knights, and the leather-capped foot soldiers halted; to the rear the baggage train and the high-wheeled wagons of the jinxmen creaked to a stop."

His output refutes the wisecrack about what is wrong with science fiction that it is neither science nor fiction. In a field cluttered with adjectivitia, with practitioners who use scientific gimmickry to cover imprecise writing, Vance shuns trickery.

"Science fiction in the far-to-medium-distant past concerned itself with scientific processes, or the consequences of some scientific quirk," he said. "Often the writers were pretty much ahead of the scientists. They `invented' any number of things which today are showing up around us. As of today, `science' is so vast in scope that no writer---unless he makes it his full-time job---can keep up."

In addition to his science-fiction work, Vance has also written several detective novels. Just as his fantasy stories explore human behavior and character, the detective work is interwoven with sociological themes. At his best he invites comparison with Utopian writers like Huxley and Orwell. As early as 1956, he was building a novel on the concept of cloning, but his real concern is how characters adjust to this radical scientific innovation.

The novel "To Live Forever" takes place in a future society where a process to halt bodily deterioration has been developed. Since overpopulation is a central problem, only a few can be given the inoculations which prevent natural death. Qualification is based on outstanding social achievement, usually in the arts and sciences. As may be expected, competition is fierce.

Everyone has an equal chance for immortality at birth. When one becomes 16 he can opt for a normal life free of stress, or aspire to the Amaranth (defined in Webster's as an imaginary flower which never fades) Society. To opt for Amaranth is to devote virtually all one's time to study, with the likelihood of immortality statistically improbable. Regardless of whether one tries for immortality or not, when a citizen lives beyond the average age, determined by a giant actuarial computer, he can expect to be visited by an assassination squad assigned by the state. The desirable level of population is thus maintained. Since accidental death is beyond scientific control, successful candidates are cloned upon acceptance.

"When an Amaranth has been admitted into the Society and had taken his final inoculations, he went into seclusion. Five cells were extracted from his body. After such modification of the genes as might be desired, they were immersed in a solution of nutrients, hormones and various special stimulants, where they rapidly evolved through the stages of embryo, infant, child and adolescent, to become five idealized simulacra of the original Amaranth. When invested with the prototype's memory-bank, they became the identity of the original: full-fledged surrogates."

Like much of Vance's writing, "To Live Forever" shows evidence of hurried work. The luxury of taking a year or two to write a book was not available to one whose books sold only moderately well. Though he says he would like to have his books make money, Vance seems, almost deliberately, to have resisted commercial success. During television's adolescent age in the 50's, he scripted several successful "Captain Video" episodes for producers who were more than satisfied. As the series progressed, more and more satire was foisted on the undiscriminating audience, seemingly out of sheer perversity. This departure from the popular mainstream resulted in the termination of Vance's services.

A similar lack of self-interest may be inferred from the unfavorable terms he permitted in the contracts with literary agents. Not only were reprint rights severely curtailed, but in more than one case, he says, he signed away all the rights to his books, necessitating their repurchase years later.

Four years ago, a sincere, 27-year old science-fiction buff entered Vance's life. Tim Underwood had the dream of publishing his favorite author and, with the innocent wisdom of youth, he bought the reprint rights to Vance's first novel, "The Dying Earth." The foresight he exhibited in enclosing a check for $500 with his request did not hurt his chances.

Underwood, a leather worker settled in San Francisco by way of Michigan, was now an incipient publisher. He acquired a partner, Chuck Miller, and the firm of Underwood/Miller began to produce finely made limited editions aimed primarily at libraries and collectors. To date they have produced nine books (seven by Vance), all done in handsome editions of about 1000 on acid-free paper with sewn-signatures, illustrated by various artists. Four more Vance books are slated for publication later this year, one of them a volume of uncollected stories. Miller distributes the books from, of all places, Pittsburgh, while Underwood handles the editorial and production work from his Richmond-District apartment.

This elegant turn of events seems to have had little effect on Jack Vance. He continues to write as he always has. A new novel, "The Face," will be published this fall by Daw Books, a paperback-original house. Like the Amaranth Society, he seems to go on forever. If that immortal group's standards were just, the scope and quality of Jack Vance's achievement would entitle him to membership.

[Sipper is a Santa Barbara rare-book dealer and a frequent contributor to the Book Review]