As a science fiction writer, the third most common question I get asked (after “Where do you get your ideas from?” and “How can I get my book published?”) is, “Why do you keep writing science fiction now that we’re living in the future?”

It’s certainly true that many of the old dreams of science fiction have been fulfilled, or bypassed. And it does feel as if we’re living through a time of accelerating change. But to imagine there is no role for science fiction in 2004 is to miss the point of the literature.

Science fiction has (rarely) been about the overt prediction of a definite future. The central rhetorical power of science fiction comes from plausibility: the future may not be like this, but it could be. But the literature is generally not so much about the future itself but a response to the tensions, anxieties and dreams of the time in which it is written. Science fiction is a response to change.

This goes back to the origins of science fiction. The literature can be seen as an offshoot of older traditions, such as tales of fantastic voyages, but authorities have traced the roots of the modern genre variously back to Mary Shelley’s Frankenstein (1818), to the work of Jules Verne and H. G. Wells in the 19th century, and to the American pulp-magazine revolution pioneered by Hugo Gernsback in the 1920s. What these disparate times have in common is that they were all points of flux, of change, scientific, technological or philosophical.

In Shelley’s time James Watt’s steam engines were offering glimpses of a new era of human power over nature — and Frankenstein is not a prediction about the age of cyborgs to come but a fable of the morality of wielding such power. In H. G. Wells’s day the great shock of evolutionary theory was working its way through society. And so Wells’s classic The Time Machine (1895) is not really a prediction of the year AD802,701 but an anguished meditation on the implications of Darwinism.

As the focus of our concerns has moved on, a whole variety of science fictional “futures” has been generated. The science fiction of the 1950s and 1960s heavily featured tales of nuclear warfare and its aftermath, in the glowing rubble of a post-holocaust world, like Walter Miller’s A Canticle for Leibowitz (1960). But there were also dreams of what it means to be human in a Universe shaped by a post-Einstein cosmology, such as Arthur C. Clarke’s The City and the Stars (1956). In the 1980s the explosion of computing power led to “cyberpunk” fantasies like William Gibson’s Neuromancer (1984). Today we dream of, or fear, the possibilities of a transhuman future opened up by information technology, biotechnology and other developments. These ideas are explored in books such as Tricia Sullivan’s Maul (2003). My own Coalescent (2003) deals with the horrors of a collective future for mankind.

Of course as time progresses some raw material becomes outdated. Neil Armstrong’s first footsteps on the Moon in 1969 made obsolete a whole library of science fictional dreams of lunar exploration, from H. G. Wells (The First Men in the Moon, 1901) to Tintin (Explorers on the Moon, 1954). But nobody would suggest expunging Wells’s great book from the canon for such a literal reason; the fiction is what counts, not the science. Meanwhile the Moon isn’ t the only goal of spaceflight dreams; there is a whole Universe out there, from Mars to the stars and beyond — plenty of room for story.

Science fiction is fiction; it is primarily entertainment. But it has always served an educational role in accustoming its readers to think about other possibilities, other places and times — to deal with change. Public debates on subjects like biotechnology are informed, if sometimes in a lurid way, by past science fictional representations: we all learnt about cloning from the mini-me Hitlers of The Boys from Brazil (1978).

Science fiction explores the consequence of change, then, but it is a way of dealing with change, of learning about it, of internalising it — not so much prophecy as a kind of mass therapy, perhaps.

The nature of the genre itself is undoubtedly evolving, however. These days you find science fiction lurking all over the place. Science fictional tropes have become so familiar and widespread that a book like Maggie Gee’s The Flood (2004), a disaster story of the near future and so on the face of it clearly science fiction, is published without reference to the genre. And a movie like The Truman Show (1999), with a premise that might have come straight from a 1950s Philip K. Dick story, can be presented as drama, not science fiction.

Even champions of the genre strive to be inclusive. The two most recent recipients of the Arthur C. Clarke Award, for the best science fiction novel published in Britain, were Christopher Priest’s The Separation, an alternate-reality fantasy of the Second World War, and Neal Stephenson’s Quicksilver, an historical novel of the 17th-century scientific revolution — neither of which Hugo Gernsback, say, would have recognised as science fiction at all.

This outreach is partly the consequence of an unfortunate snobbery about the genre label. This is driven largely by the perception of media science fiction, some of which — Star Wars, Star Trek — can be decades behind the best of the prose, though the best, like The Matrix (1999), deserves attention and praise. This can lead to challenges for the publishers, such as the distancing of Margaret Atwood’s futuristic Oryx and Crake (2003) from the taint of genre.

But surely the very success of science fiction in shaping our modern world-view and as a source of fictional techniques and possibilities is responsible for its own propagation. In a recent interview (in Locus, the science fiction newsletter) Terry Pratchett said: “Science fiction is like some big generation ship that’s crash-landed on a planet, and in order to build new structures people are taking away bits of it. You can still see the shape of the thing, but everything has been cannibalised for different purposes . . . I don’t particularly think this is bad.” Science fiction has been assimilated, but it’s still there.

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