On Greatest Lit list:
• Riverworld (1971–83)
• World of Tiers (1965–77)
• Dayworld (1985–90)
At a relatively late age for a novice writer, Philip Josť Farmer won acclaim for his first science-fiction novella The Lovers (1952), which combined alien biology and sex. It worked so well that the American author worked the same features into his novels and stories forever after. One of his noteworthy early stories was "Open to Me, My Sister", whose title gives an idea why it was considered "disgusting" by potential publishers.
Not that Farmer's tales all strike the same note. In fact, they include some of the most varied and exotic writing in sci-fi, sometimes crossing over into the fantasy realm. His Father Carmody series of stories in the 1950s features a murderous priest who sorts out theological puzzles on various planets. In his novel The Wind Whales of Ishmael (1971) the sole survivor of Herman Melville's Moby Dick falls through time into a future Earth when the oceans have dried up and primitive people have taken to the skies in airships powered by gas-filled animal bladders.
Between 1965 and 1977 he produced an imaginative and humorous series of novels known collectively as World of Tiers, which gained a following. The first in the series, Maker of Universes, begins with mild-mannered professor Robert Wolff walking through a wall into another universe. In a world of stacked environments he must fight his way through various levels to regain his rightful place as ruler (a life he had apparently forgotten during his stay on earth). The world-hopping fun continues in The Gates of Creation but Wolff's ally, the pleasure-loving trickster, Paul Janus Finnegan (also known as Kickaha) comes to steal the reader's interest—to take over as the central character in the rest of the series with A Private Cosmos, Behind the Walls of Terra and The Lavalite World. The series was revised and republished in the early 1980s.
Farmer's greatest work however is the more serious Riverworld collection (1971–83), starting with the Hugo Award-winning To Your Scattered Bodies Go. Everyone who has ever lived is resurrected on a planet alongside a mysterious long river. The quest to discover the purpose behind this created world is carried out by real-life figures from earth's history—including Richard Burton (the explorer), Samuel Clemens, King John, Herman Goering, Jack London, and Cyrano de Bergerac—along with fictional personalities, such as Naz, the friendly Neanderthal, as the series continues with The Fabulous Riverboat, The Dark Design, The Magic Labyrinth, Gods of Riverworld and more works by both Farmer and other writers who have joined the fray.
Other notable entries in the Farmer oeuvre:
• Tarzan Alive: A Definitive Biography of Lord Greystoke (1972), a pretend biography of Edgar Rice Burroughs' fictional apeman, employing Joseph Campbell's ideas about mythology.
• The prize-winning, punning novella Riders of the Purple Wage (1967).
• Venus on the Half-Shell (1975), which Farmer wrote under the name of Kilgore Trout, an SF-writing character from a novel by Kurt Vonnegut, Jr. Confused yet? There's more. Farmer later wrote some stories as Jonathan Swift Somers III, a character in Venus on the Half-Shell written by Kilgore Trout — or Farmer...or....
• The Unreasoning Mask (1981), a novel that mixes space opera with cosmic speculation, including concepts such as multiverses, human space travel as a carcinogen to be fought by humongous antibodies, an idiot god — hard to follow at times but thought-provoking.
• The Dayworld series (1985-90) in which overpopulation has forced every body to be shared by seven people, each taking a turn for a day of every week.
• The Wold Newton Family project which tries to tie together many of Farmer's and other authors' works into one grand, chaotic scheme.
And lots more. Not everything Farmer does works, but it's fun to watch him try.