Science fiction is a genre of fiction. It differs from fantasy in that, within the context of the story, its imaginary elements are largely possible within scientifically-established or scientifically-postulated laws of nature (though some elements in a story might still be pure imaginative speculation). Exploring the consequences of such differences is the traditional purpose of science fiction, making it a "literature of ideas". Science fiction is largely based on writing entertainingly and rationally about alternate possibilities in settings that are contrary to known reality.
- Science fiction is the search for a definition of man and his status in the universe which will stand in our advanced but confused state of knowledge (science), and is characteristically cast in the Gothic or post-Gothic mould.
- Brian Aldiss, Billion Year Spree: The True History of Science Fiction (1973), Ch. 1: "The Origins of the Species"
- The hardest theme in science fiction is that of the alien. The simplest solution of all is in fact quite profound — that the real difficulty lies not in understanding what is alien, but in understanding what is self. We are all aliens to each other, all different and divided. We are even aliens to ourselves at different stages of our lives. Do any of us remember precisely what it was like to be a baby?
- Greg Bear, "Introduction to 'Plague of Conscience' ", The Collected Stories of Greg Bear" (2002)
- Science-fiction works hand-in-glove with the universe.
- Ray Bradbury, "Introduction" in The Circus of Dr. Lao and Other Improbable Stories (1956)
- Science fiction is the most important literature in the history of the world, because it's the history of ideas, the history of our civilization birthing itself. ...Science fiction is central to everything we've ever done, and people who make fun of science fiction writers don't know what they're talking about.
- Ray Bradbury, Brown Daily Herald, March 24, 1995
- I hate the whole ubermensch, superman temptation that pervades science fiction. I believe no protagonist should be so competent, so awe-inspiring, that a committee of 20 really hard-working, intelligent people couldn't do the same thing.
- No less a critic than C. S. Lewis has described the ravenous addiction that these magazines inspired; the same phenomenon has led me to call science fiction the only genuine consciousness-expanding drug.
- Arthur C. Clarke, "Of Sand and Stars", 1983
- Nothing is deader than yesterday's science-fiction.
- Arthur C. Clarke, The Sands of Mars, 1951.
- SF has never really aimed to tell us when we might reach other planets, or develop new technologies, or meet aliens. SF speculates about why we might want to do these things, and how their consequences might affect our lives and our planet.
- John Clute, Science Fiction: The Illustrated Encyclopedia (1995)
- Science fiction is, after all, the art of extrapolation.
- It is absurd to condemn them [science fiction stories] because they do not often display any deep or sensitive characterization. They oughtn't to. ... Every good writer knows that the more unusual the scenes and events of his story are, the slighter, more ordinary, the more typical his persons should be. Hence Gulliver is a commonplace little man and Alice is a commonplace little girl. If they had been more remarkable they would have wrecked their books. The Ancient Mariner himself is a very ordinary man. To tell how odd things struck odd people is to have an oddity too much; he who is to see strange sights must not himself be strange.
- C. S. Lewis, "On Science Fiction", 24 November 1955 talk to the Cambridge University English Club on; published posthumously in Of Other Worlds: Essays and Stories (1966)
- I like to present my characters—whether they are in the past or in the future—with interesting moral choices, and it seems to me that science-fiction writers are, or should be, the prophets and moralists of today. I am fairly well up on the biological sciences, but I am deeply uninterested in gadgets. A writer's job is to write about people with sympathy and insight.
- Naomi Mitchison, in Anthony Wolk, "Challenge the Boundaries: An Overview of Science Fiction and Fantasy," The English Journal 79 (1990), p. 27.
- Sci-fi can be succinctly defined as speculation, whether based on established scientific facts or on logical pseudo-facts consistent with the framework of the fiction in question, involving smelly green pimply aliens furiously raping or eating, or both, beautiful naked bare-breasted chicks, covering them in slime, red, oozing, living slime, dribbling from every horrific orifice, squeezing out between bulbous pulpy lips onto the sensuous velvety skin of the writhing sweating slave-girls, their bodies cut and bruised by knotted whips brandished by giant blond vast-biceped androids called Simon, and written in the Gothic mode.
- Peter Nicholls, True Rat 7 (1976)
- Science fiction rarely is about scientists doing real science, in its slowness, its vagueness, the sort of tedious quality of getting out there and digging amongst rocks and then trying to convince people that what you're seeing justifies the conclusions you're making. The whole process of science is wildly under-represented in science fiction because it's not easy to write about. There are many facets of science that are almost exactly opposite of dramatic narrative. It's slow, tedious, inconclusive, it's hard to tell good guys from bad guys — it's everything that a normal hour of Star Trek is not.
- Remember that Jules Verne was a sort of Shakespeare of science fiction, and we would feel derelict if we did not give his stories in our columns.
- The "hard" science-fiction writers are the ones who try to write specific stories about all that technology may do for us. More and more, these writers felt an opaque wall across the future. Once, they could put such fantasies millions of years in the future. Now they saw that their most diligent extrapolations resulted in the unknowable ... soon.
- Vernor Vinge, "The Coming Technological Singularity" (1993)
- I have been a soreheaded occupant of a file drawer labeled "Science Fiction" ever since, and I would like out, particularly since so many serious critics regularly mistake the drawer for a urinal.
- Kurt Vonnegut, The New York Times Book Review, 5 September 1965; reprinted in Wampeters, Foma & Granfalloons (1974)
- We hope it will not be long before we may have other works of Science-Fiction [like Richard Henry Horne’s ‘‘The Poor Artist’’], as we believe such books likely to fulfil a good purpose, and create an interest, where, unhappily, science alone might fail. [Thomas] Campbell says, that ‘‘Fiction in Poetry is not the reverse of truth, but her soft and enchanting resemblance.’’ Now this applies especially to Science-Fiction, in which the revealed truths of Science may be given, interwoven with a pleasing story which may itself be poetical and true—thus circulating a knowledge of the Poetry of Science, clothed in a garb of the Poetry of life.
- A Little Earnest Book upon a Great Old Subject by William Wilson, 1851.
- This is the first recorded use of the term science fiction in history.