For 25 years and counting, Gary K. Wolfe has been the principal book reviewer for Locus, the essential magazine for anyone interested in fantasy and science fiction. A professor of the humanities at Chicago’s Roosevelt University, he is also the editor of the Library of America’s “American Science Fiction: Nine Classic Novels of the 1950s” and is currently at work on a companion set focusing on the 1960s. Over the years, I’ve often heard him speak about established, neglected and emerging science-fiction writers, always with precision and measured elegance. As they say of James Bond, nobody does it better.

You’ll recognize this as soon as you begin to listen to Wolfe’s Great Courses lectures in “How Great Science Fiction Works.” He opens by defining his subject by borrowing a simple, but useful observation from Samuel R. Delany: Realistic fiction is concerned with events that could have happened, fantasy with events that could not have happened, and science fiction with events that have not happened or not happened yet. Following a brief nod to some instances of proto-sf (Lucian, Thomas More, Swift), Wolfe then begins in earnest by examining Mary Shelley’s “Frankenstein.”

To date the birth of modern sf to this 1818 novel isn’t a new idea. Brian W. Aldiss first suggested it in the initial version of “Trillion Year Spree,” a standard history of the field, which he co-authored with David Wingrove. Wolfe forthrightly acknowledges Aldiss, as he did Delany. This same critical graciousness runs throughout these lectures. When Wolfe talks about utopias and dystopias, pulp magazines, “the robot from Čapek to Asimov,” the spaceship as an icon, or the themes of evolution, deep time and the wasteland, he brings to bear everything he has thought and read and reviewed. He clearly loves science fiction and wants you to understand why. His accompanying booklet consequently offers recommended readings, discussion questions and an extensive, annotated bibliography of both primary and secondary texts.

Above all, Wolfe reminds us that modern sf isn’t “all that Buck Rogers stuff,” let alone comic-book movies consisting largely of special effects. H.G. Wells’s “The Time Machine,” Olaf Stapledon’s “Star Maker,” George R. Stewart’s “Earth Abides,” Walter M. Miller Jr.’s “A Canticle for Leibowitz,” Ursula K. Le Guin’s “The Left Hand of Darkness,” Gene Wolfe’s “The Book of the New Sun” — these are serious works of literature, as thought-provoking and beautifully written as any fiction you will ever read.

To underscore contemporary sf’s global reach and cultural diversity, Wolfe devotes his penultimate lecture to the novels of Nalo Hopkinson, Nnedi Okorafor and Lavie Tidhar. He then brings his thoughtful and wonderfully entertaining course to a close by pointing listeners to one final classic: Daniel Keyes’s “Flowers for Algernon.” No one who has ever read this heart-rending story can ever doubt the artistry and literary power of great science fiction.

(Black Coat Press)

While Gary Wolfe is a superb critic, reviewer and teacher, Brian Stableford is something even rarer: fantastic literature’s leading scholar and historian. In just the past year, he has brought out two long-planned, magisterial works of literary excavation, “New Atlantis: A Narrative History of Scientific Romance” (Wildside, four vols; paperback, $15.99 each) and, late this spring, the even more groundbreaking survey, “The Plurality of Imaginary Worlds: The Evolution of French Roman Scientifique.”

In these parallel studies, Stableford argues for national differences in the American, British and French traditions of fantastic literature. To overgeneralize, American science fiction grows out of pulp-magazine storytelling, while the British scientific romance emphasizes social criticism and satire. But in France, as Stableford shows, the “roman scientifique” or “scientific novel” is primarily idea-focused, being rooted in both the philosophical fables of Cyrano de Bergerac and Voltaire and in the distinctly transgressive works of 18th-century pornographers and 19th-century political radicals.

“The Plurality of Imaginary Worlds” meticulously tracks French representations of the marvelous from the early Middle Ages to the outbreak of World War II. Yet only a few of the writers covered are likely to be familiar to American readers: Jules Verne, of course; probably astronomer Camille Flammarion, author of “Omega: The Last Days of the World” (1893); and, perhaps, J.-H. Rosny, who wrote my own favorite alien encounter story, “The Xipéhuz” (1887), as well as the novel behind “Quest for Fire,” the 1981 film about prehistoric humankind. Happily, Stableford summarizes virtually all the works he discusses, and even more happily has been translating many of them for Black Coat Press.

On the most basic level, “The Plurality of Imaginary Worlds” provides a book list for the adventurous reader. Stableford tells us that Restif de la Bretonne’s “The Discovery of the Austral Continent by a Flying Man, or The French Daedalus” (1781) is “undoubtedly the most significant work of science-based speculative fiction produced before the 1789 Revolution.” We learn that Louis Geoffroy’s “The Apocryphal Napoleon” (1841) might well be the first work of alternate history. In it, Napoleon’s invasion of Russia proves successful and the Corsican upstart eventually becomes the Sovereign of the World. Humorist Albert Robida’s “Saturnin Farandoul” (1879) takes its Baron Munchausen-like title character and has him tangle with Captain Nemo, Phileas Fogg, Michael Strogoff and other Jules Verne heroes. In “The Blue Peril ” (1911), Maurice Renard brilliantly depicts a race of spider-like aliens who live in the upper atmosphere of the Earth. Villiers de l’Isle-Adam’s “Tomorrow’s Eve” (1886) features a female android created by none other than Thomas Edison. In “Caresco, Superman” (1904), André Couvreur imagines the perfect utopia as a kinky sexual paradise.

As a scholar, Brian Stableford can’t be faulted, at least not by me. However, his prose, while clear enough, does tend to be loose and baggy, and sometimes a word — through inattentive proofreading — will have been left out of a sentence. Such quirks and blemishes hardly matter, though, given that “The Plurality of Imaginary Worlds” invites its readers to explore an entire galaxy of unfamiliar and exciting fiction.

Michael Dirda reviews books on Thursdays in Style.

HOW GREAT SCIENCE FICTION WORKS

By Gary K. Wolfe

The Great Courses. 12-1/2 hours. Available on DVD, CD and for download

THE PLURALITY OF IMAGINARY WORLDS
The Evolution of French Roman Scientifique

By Brian Stableford

Black Coat. 672 pp. Paperback, $49.95