THE CENTRAL literary conceit of the cycle of linked tales that Samuel R. Delany calls "Return to Neve`ryon" is explained by his alter-ego K. Leslie Steiner in a preface that appears at the end of the fourth and most recent book in the series, The Bridge of Lost Desire (Arbor House, $17.95). According to Steiner, "Delany's stories are, among other things, a set of elaborate and ingenuous deconstructions" of an Ur text called the Culhar', "that ancient, fragmented, and incomplete narrative, with its barbarians, dragons, sunken cities, reeds and memory marks, twin-bladed warrior women, child ruler, one-eyed dreamer and mysterious rubber balls." That is, the tales of Neve`ryon are postmodern sword-and-sorcery.

Sword-and-sorcery has lurked on the fringes of sf and fantasy since the 1930s, when Robert E. Howard fused historical adventure with supernatural horror in his tales of Conan the Barbarian. Most examples of this largely despised sub-genre are banal and artless, simplemindedly plotted and hamstrung with the most rigid set of conventions you'll find outside of a Harlequin romance. Not so the tales of Neve`ryon.

In lieu of the generic mighty-thewed, empty-headed barbarian, Delany gives us Gorgik, an ex-mine slave and teller of tales who, as recounted in "The Tale of Gorgik," overthrows the institution of slavery in Neve`ryon and, in the process, becomes civilized. Introspective and literate, Gorgik is the barbarian as semiotician, given to anachronistically sophisticated thoughts such as, "Where do I look for a model, a mirror, an image of the questing self seeking self-knowledge?"

Gorgik features prominently in two of the tales in The Bridge of Lost Desire. The protagonist of the third and most complex, "The Tale of Rumor and Desire," is his counterpart, a brutish thief and murderer aptly named Clodon. The adolescent and adult adventures of this ne'er-do-well revolve prismatically around the twin polarities of slavery and lust, and freedom and desire.

In fact, these themes dominate all the tales of Neve`ryon. In this book, as in its predecessors, Delany subverts the formulaic elements of sword-and-sorcery and around their empty husks constructs self-conscious metafictions about social and sexual behavior, the play of language and power, and -- above all -- the possibilities and limitations of narrative. Immensely sophisticated as literature, the tales in The Bridge of Lost Desire are also eminently readable and gorgeously entertaining.

Many of the issues that underlie Delany's tales of Neve`ryon appear in the foreground of his autobiography The Motion of Light in Water (Arbor House/Morrow, $17.95). This memoir of "Sex and Science Fiction Writing in the East Village, 1957-1965" tells two stories. One is the familiar stuff of autobiography: how young Chip Delany -- poor, gay, black, intensely intellectual and enormously talented -- survived "the low-key nightmare" of his marriage to poet Marilyn Hacker and a subsequent breakdown to ultimately define "the limits of {his} own sexual map" and come to accept that he was "that most ambiguous of citizens, the writer."

But the other story -- the one that animates the first -- is the more interesting: how the mature Samuel R. Delany grappled with the esthetic and epistemological problem of autobiography. Because he must adhere to facts, the autobiographer cannot shape a work of the artistic symmetry of, say, the novel. But, because he must shape those imperfectly remembered and inherently subjective facts using the limited medium of language, neither can he shape a work of truth, for "history (as one evokes it in biography, in autobiography) is what most of us do not remember, what most of us cannot speak of."

Delany's resolution of this tension is to acknowledge that the act of autobiography is fiction-making. Introducing The Motion of Light in Water, he alerts us that "even as I work after honesty and accuracy, memory will make this only one possible fiction among the myriad -- many in open conflict -- anyone might write of any of us, as convinced as any other that what he or she wrote was the truth."

Thus placing this memoir/essay/study in "the hugely arbitrary postmodern," Delany tells his story. He writes, with the honesty essential to autobiography, of the people he knew and the books he wrote, of his dyslexia and acrophobia, of his obsessions with hands and subways, and of the meaning of his avocation, sexual orientation, and color. But throughout The Motion of Light in Water he remains a presence both as subject and as author, never letting us forget that what we are reading is, in fact, a fiction.

Art Attacks

IN THE YEARS following 1965, Delany began to publish the essays -- gathered in The Jewel-Hinged Jaw and Starboard Wine -- that eventually would make his reputation as one of the most thoughtful and rigorous critics of sf and fantasy. At the same time, John Clute rose to a similar prominence through review columns published in such magazines as Fantasy and Science Fiction, New Worlds and Foundation. At last someone (Serconia Press, P.O. Box 1786, Seattle, WA 98111) has published a handful of these sometimes hilarious, sometimes maddening, but always insightful pieces as Strokes: Essays and Reviews 1966-1986 (Serconia, $16.95; paperback, $8.95)

Aside from his intelligence, deep understanding of sf, and wide-ranging knowledge of literature, what makes Clute so astute a reviewer is the seriousness with which he takes science fiction. While he acknowledges that it is "generic writing, composed, marketed, and read according to laid-down expectations regarding form and content," he refuses to accept the corollary that sf is an enclave. He presents himself not as a fan but as a "congenital exile" setting about "the job of dissevering joy from glop."

In the best of these essays, Clute homes in on the essence of his subject, be it a writer's oeuvre, an individual story, or a whole class of texts -- as, for example, in his compact characterization of hard sf as "glossy, technophilic, ornate, savvy about the frontiers of knowledge, power-obsessed in the name of hardnosed realism: great on carapace; vacuous on the inner depths." Clute approaches the (few) works he considers excellent with seriousness but not reverence and everything else with a "comic animus" that only occasionally slips into an "excess of rudeness and vituperation."

But while Clute is capable of prose of piercing clarity, he is sometimes culpable of a style of stupefying opacity. In several of his essays for New World, for example, seemingly endless sentences clotted with words such as emphysematious, superfetation, and esemplasy stand as blockades on the road to understanding.

Still, even at its most self-consciously baroque, Clute's writing remains energetic and his insights acute. And the high points of Strokes -- the long essay on "the terrible secret meaning of the ghost-ridden world of {British writer Robert} Aickman's fiction" and the brilliant "decipherment" of Gene Wolfe's The Book of the New Sun -- show just how fine a critic he can be.

A Guide to the Stars

AN UNAVOIDABLE defect of a collection of review colums such as Strokes is that it depicts the genre as a patchwork quilt. A perfect antidote to such incompleteness is the latest edition of Neil Barron's Anatomy of Wonder (Bowker, $39.95), a book likely to be of interest to anyone with more than a passing interest in sf.

The first edition of this awesomely comprehensive critical guide, including contributions from some of the finest critics in the field, was published in 1976 and promptly established itself as invaluable. Now, greatly enlarged, extensively revised, and updated in this, its third incarnation, Anatomy of Wonder embraces the whole diverse spectrum of science fiction on the planet.

Indeed, where else can one find thoughtful essays on, say, Belgian, Yugoslavian, and Romanian sf, supplemented by capsule summaries of major works that most of us will never see and couldn't read if we did? Or extensive, ruthlessly annotated guides to histories, critical works, teaching aids, studies of film and television, magazines, libraries, and private collections, accompanied by a thoughtful, carefully constructed "best-books listing" that ought to be the starting point for any reader's library of science fiction?

But for many readers the heart of Anatomy of Wonder will be its coverage of (adult and children's) English-language sf. These five long chapters tell of the birth of science fiction in post-Renaissance tales of imaginary voyages, its maturation during the years of World Wars I and II, and its prodigal adulthood.

Reading the thoughtful, literate essays in this book and the hundreds of accompanying commentaries, we come to understand how science fiction has evolved into a vast and variegated literature that, in works as diverse as Delany's tales of Neve`ryon and the far-future potboilers skewered in Clute's Strokes, speaks with unique relevance to our strange, postmodern times.

Michael A. Morrison, professor of physics at the University of Oklahoma, writes frequently about fantasy, horror and science fiction. He is at work on "The American Nighmare," a study of the fiction of Dennis Etchison.