The Null Device
Margaret Atwood on the difference between science fiction and speculative fiction:
Speculative fiction encompasses that which we could actually do. Sci-fi is that which we’re probably not going to see. We can do the lineage: Sci-fi descends from H.G. Wells’ War of the Worlds; speculative fiction descends from Jules Verne’s Twenty Thousand Leagues Under the Sea.
Out of Twenty Thousand Leagues Under the Sea came Edward Bellamy’s Looking Backward, out of which came We by Yevgeny Zamyatin, then George Orwell’s 1984 and Aldous Huxley’s Brave New World. Ray Bradbury’s Fahreneheit 451 was speculative fiction, while The Martian Chronicles was not.