Science Fiction Definitions
Authors have struggled to define the genre over the decades; here are some of the most thought-provoking definitions:
Science fiction is the search for 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 W. Aldiss in Trillion Year Spree: the History of Science Fiction (London, 1986)
Modern science fiction is the only form of literature that consistently considers the nature of the changes that face us, the possibleconsequences, and the possible solutions...That branch of literature which is concerned with the impact of scientific advance upon human beings.—Isaac Asimov
Science fiction is really sociological studies of the future, things that the writer believes are going to happen by putting two and two together. —Ray Bradbury
We talk a lot about science fiction as extrapolation, but in fact most science fiction does not extrapolate seriously. Instead it takes a willful, often whimsical, leap into a world spun out of the fantasy of the author... In fact, one good working definition of science fiction may be the literature which, growing with science and technology, evaluates it and relates it meaningfully to the rest of human existence.—H. Bruce Franklin
A handy short definition of almost all science fiction might read: realistic speculation about possible future events, based solidly on adequate knowledge of the real world, past and present, and on a thorough understanding of the nature and significance of the scientific method. To make this definition cover all science fiction (instead of "almost all") it is necessary only to strike out the word "future." —Robert A. Heinlein in Science Fiction: its nature, faults and virtues, in The Science Fiction Novel, Advent, Chicago:1969
Science Fiction is speculative fiction in which the author takes as his first postulate the real world as we know it, including all established facts and natural laws. The result can be extremely fantastic in content, but it is not fantasy; it is legitimate--and often very tightly reasoned--speculation about the possibilities of the real world. This category excludes rocket ships that make U-turns, serpent men of Neptune that lust after human maidens, and stories by authors who flunked their Boy Scout merit badge tests in descriptive astronomy.—Robert A. Heinlein in Ray Guns And Spaceships, in Expanded Universe, Ace, 1981
Fantasy is the impossible made probable. Science Fiction is the improbable made possible.— Rod Serling