Out of Context: On Science Fiction (Definitions)

"Science fiction is a kind of archaeology of the future." (Clifton Fadiman, 1951)

"[Science fiction is] that class of prose narrative treating of a situation that could not arise in the world we know, but which is hypothesised on the basis of some innovation in science or technology, or pseudo-science or pseudo-technology, whether human or extra-terrestrial in origin. It is distinguished from pure fantasy by its need to achieve verisimilitude and win the 'willing suspension of disbelief' through scientific plausibility." (Kingsley Amis, "New Maps of Hell", 1960)

"Science fiction is no more written for scientists than ghost stories are written for ghosts." (Brian W Aldiss (Ed.), "Penguin Science Fiction", 1961)

"It is said that science fiction and fantasy are two different things. Science fiction is the improbable made possible, and fantasy is the impossible made probable." (Rod Serling, The Twilight Zone, "The Fugitive", 1962)

"Science fiction is, very strictly and literally, analogous to science facts. It is a convenient analog system for thinking about new scientific, social, and economic ideas - and for re-examining old ideas." (John W Campbell Jr., "Prologue to Analog", 1962)

"Science fiction is not prescriptive; it is descriptive." (Ursula K Le Guin, "The Left Hand of Darkness", 1969)

"Science fiction is held in low regard as a branch of literature, and perhaps it deserves this critical contempt. But if we view it as a kind of sociology of the future, rather than as literature, science fiction has immense value as a mind-stretching force for the creation of the habit of anticipation." (Alvin Toffler, "Future Shock", 1970)

"Science fiction is the branch of literature that deals with the effects of change on people in the real world as it can be projected into the past, the future, or to distant places. It often concerns itself with scientific or technological change, and it usually involves matters whose importance is greater than the individual or the community; often civilization or the race itself is in danger." (James Gunn, "Road to Science Fiction" Vol. 2, 1979)

"If science fiction is the mythology of modern technology, then its myth is tragic." (Ursula K Le Guin, "Dancing at the Edge of the World", 1989)

"Science fiction is about what could be but isn't; fantasy is about what couldn't be." (Orson S Card, "How to Write Science Fiction & Fantasy", 1990)

"Science fiction is essentially a kind of fiction in which people learn more about how to live in the real world, visiting imaginary worlds unlike our own, in order to investigate by way of pleasurable thought-experiments how things might be done differently." (Brian Stableford, "Space, Time, and Infinity: Essays on Fantastic Literature", 2006)

"Anything you dream is fiction, and anything you accomplish is science, the whole history of mankind is nothing but science fiction." (Ray Bradbury)

"Fantasy is the impossible made probable. Science Fiction is the improbable made possible." (Rod Serling) 

"General fiction is pretty much about ways that people get into problems and screw their lives up. Science fiction is about everything else." (Marvin Minsky)

"[...] science fiction is something that could happen - but usually you wouldn't want it to. Fantasy is something that couldn't happen - though often you only wish that it could." (Arthur C Clarke)

"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)

"Science fiction is very well suited to asking philosophical questions; questions about the nature of reality, what it means to be human, how do we know the things that we think we know." (Ted Chiang)

"Science fiction is, after all, the art of extrapolation." (Michael Dirda)

"Science fiction, outside of poetry, is the only literary field which has no limits, no parameters whatsoever." (Theodore Sturgeon)