Despite a few surface similarities such as having the same readers and writers, fantasy and science fiction have far less in common than most think. Let's take a look at the history of each and see what they reveal:
Fantasy
Fantasy is the descendant of myth, fairy tale, and legend; the stories of Zeus, Osiris, and a thousand other gods; the tales retold by the Brothers Grimm and Hans Christian Andersen - most have common themes, similar motifs, archetypes that have survived for millenia. In 1948 Joseph Campbell traced the common thread of myth in his book The Hero With a Thousand Faces using the psychological theories of his day as justification (my review of the book, for more detail).
A subset of the motifs used in mythology have survived and live on in modern fantasy. Most modern fantasy is fashioned after one of the first and greatest works of fantasy, J.R.R. Tolkien's The Lord of the Rings. Most or all best-selling fantasy series have many of the same motifs including those by Robert Jordan, David Eddings, Terry Brooks, and Tad Williams.
The prototypical fantasy story is as follows:
A seemingly common man finds that the fate of the world rests on his shoulders. A great evil threatens, and he holds the key to preventing universal ruin. The quest is presented by a wise one who will serve as mentor and guide through the course of the story. The hero accepts the quest, but reluctantly - it is important that he not be seeking glory and power, because that is exactly the type of person that he is there to defeat. The hero then assembles a group of friends with extraordinary abilities to help him on his quest. Often, though not always, he finds that he was fated for this quest, and that he has unknown and untapped internal powers. The hero musters his courage, completes the quest, and returns to his life, albeit changed, reborn.
There are many partial exceptions to the recipe outlined above, but few with a truly different flavor. Fantasy is about strict adherence to archetypes - new themes bring a bitter taste.
Science Fiction
Science fiction's origins are vastly different than those of fantasy. Although it technically existed earlier, sci-fi didn't really flourish until around 1930, the age of pulp.
Around that time a number of pulp magazines sprung up, edited by fellows such as Hugo Gernsback and John W. Campbell (completely different Campbell from the one mentioned earlier). They recruited enterprising young men such as Isaac Asimov, Robert Heinlein, and Theodore Sturgeon to write short stories at a couple pennies per word. Thus, a genre was born.
During what is often referred to as "the golden age" of science fiction, much of the work produced was in short form, either in magazines or anthologies. The novel steadily gained ground, however, and in the late '60s or early '70s short fiction was on the decline.
Unlike fantasy, science fiction has a multitude of themes, with no strictures against violating preconceptions. Although science fiction is fundamentally about people, many of the story ideas arose from...surprise...science. Many of the early writers in fact were scientists - Isaac Asimov, for instance, was a chemist. As such, they turned to the scientific method and what is known in physics as a "gedanken experiment."
A popular method of experimentation is to change one variable and see the results. A gedanken (german for thought) experiment is one that is carried out in the head because it's impractical to do in reality. Combine these two ideas, apply them to humanity, and a story is born. For instance, what would our society be like if drugs were used for everything? How would our society differ if people were hermaphrodites? Science fiction shows us who we are by showing us humanity under extreme circumstances, often with surprising but telling results.
Because of its origins in short fiction and basis in experimentation, science fiction often has neither the time nor the inclination to adhere to the themes present in fantasy and other genres. Sci-fi still has its themes, but they are routinely violated.
Blurring The Line
Of course, attempts at classification can be made difficult by those stories with a foot on each side of the line. Star Wars, for example, has the structure of a fantasy story with the trappings of science fiction (George Lucas is a fan of Joseph Campbell's theories). Such stories no doubt contribute to the close kinship shared by fantasy and science fiction.
Regardless of how you want to define the genres, they both have a wealth of fine stories that should both entertain and educate you, if you keep your eyes open. Follow the links for a few of my favorites.
