I'm a science fiction fan, but I've also come to realize that as a fan and a student of literary theory, I make a pretty good science fiction critic.

Science fiction literature and film are two of the most socially charged genres of literature (I suppose I could just say "media"). Serious science fiction -- not the stuff by Robert Aspirin and the like -- deals with issue that we confront every day, especially if science fiction is set in the future.

Darko Suvin, probably the world authority on science fiction criticism, defines science fiction this way:

SF is distinguished by the narrative dominance or hegemony of a fictional "novum" (novelty, innovation) validated by cognitive logic. [...] Quantitatively, the postulated innovation can be of quite different degrees of magnitude, running from the minimum of one discrete new "invention" (gadget, technique, phenomenon, relationship) to the maximum of a setting (spatiotemporal locus), agent (main character or characters), and/or relations basically new and unknown to the author's environment. [...] The novum is postulated on and validated by the post-Cartesian and post-Baconian scientific method. This does not mean that the novelty is primarily a matter of scientific facts or even hypotheses; and insofar as the opponents of the old popularizing Verne-to-Gernsback orthodoxy protest against such a narrow conception of SF they are quite right. But they go too far in denying that what differentiates SF from the "supernatural" literary genres (mythical tales, fairy tales, and so on, as well as horror and/or heroic fantasy in the narrow sense) is the presence of scientific cognition as the sign or correlative of a method (way, approach, atmosphere, sensibility) identical to that of a modern philosophy of science. Science in this wider sense of methodically systematic cognition cannot be disjoined from the SF innovation, in spite of fashionable currents in SF criticism in the last 15 years -- though it should be conversely clear that a proper analysis of SF cannot focus on its ostensible scientific content or scientific data. Indeed, a very useful distinction between "naturalistic" fiction, fantasy, and SF, drawn by Robert M. Philmus, is that naturalistic fiction does not require scientific explanation, fantasy does not allow it, and SF both requires and allows it. (Darko Suvin, Metamorphoses of Science Fiction: On the Poetics and History of a Literary Genre, 63-65.)

What does this mean? It means that science fiction (1) deals with some new innovation, which can also be a character or setting in addition to a thing. (2), The innovation's operation must be supported by what we call the scientific method; that is, its nature and function must be explainable through logic and reason and that operation and function must be supported through empirical (observable) means. Suvin uses the word "supernatural," which is a key component of what science fiction is not. If anything, science fiction grounds itself in the natural: in the rational, observable world. Something which exists beyond our own realm of being is off-limits -- unless it is explained through logic, reason, and empirical support. Thus the USS Enterprise is an element of science fiction because we can see that it operates utilizing an innovation (warp drive, let's say) which is explainable via scientific reasoning; that is, the ship does not go "because we say so" or because of a magic spell. It goes because of a complex reaction between matter and antimatter, mediated by a dilithium crystal, producing high-energy charged plasma, which feeds drive coils that produce a warp field that makes the ship go.

Why is it so important to pin down what science fiction is? Science fiction critics want to first define the genre and then see how that genre interacts with other genres, producing science fiction fantasy (Star Wars) and science fiction horror (Alien). Ursula K. Le Guin subsumes science fiction under fantasy, which is probably a safe bet. If we were going to divide literature into realms of realism, we would probably have "naturalistic fiction" (fiction that aims to replicate or duplicate the conditions of the author's present time and place, what Suvin calls a "spatiotemporal locus") and "fantastic fiction" (fiction that is set in a time and place that is not the author's time and place).

Even these genres get confusing, though. Stephen King produces what we might call "naturalistic horror." His characters are normal people like us and they live in normal places like we do, in our own time. This is why his stories are so frightening: the possibility exists in Stephen King that the horrific, a world usually relegated to fantasy, can enter our own world. We don't have to travel to Transylvania to encounter a vampire. One might exist in our own backyard, in our quiet Maine town, and we wouldn't know it until it was too late. Horrifying things can be found in normal places: the sub-basement of an old mill, a Colorado hotel, suburban America, or even a laundromat.

Michael Crichton writes "naturalistic science fiction," in which characters from our own time and place utilize a novum, whether it is dinosaur DNA (Jurassic Park), a time machine (Timeline), an alien spacecraft (Sphere), or an embedded microchip (The Terminal Man). His characters are, again, like us, but they find themselves in situations unlike ours through the use of scientific innovations. Ultimately, something goes horribly wrong with these innovations -- man has overstepped his boundaries -- and the characters have to get out of a precarious situation, usually with some sort of time limit (in Jurassic Park the book, Grant and the kids had to get back to the control room to stop a boat laden with hidden velociraptors before it arrived on the mainland).

Isaac Asimov's The Gods Themselves is a good example of fantastic science fiction, "real" science fiction. His novel is set alternatively on Earth of the future, Moon of the future, and an alternate dimension of the future. Its novum is a gateway between our dimension and an alien dimension that allows the transfer of energy between the two dimensions. This innovation is not magic; it operation is explained meticulously to the reader.

Science fiction has something to say about our society. Horror has something to say about our selves. Michael Crichton's The Terminal Man is a treatise on unchecked technological progress that could ultimately result in the dehumanization of man by technology. He wrote the book at the mere beginning of the computer revolution. Stephen King's The Stand deals with the nature of evil, something that has existed and will always exist even if society no longer exists (spolier: cf. the ending where Randall Flagg, the Dark Man, washes ashore on an island inhabited by primitive people; society is not a prerequisite for evil. It is man's nature to be evil as well as good).

We divide things into genres to see how one genre is different from another, and see how they interact and change over time. There will be more discussions of science fiction, its nature and its change, in this space -- you can count on that.