Aliens, time travel, sorcerers, and dragons! The domains of Science Fiction and Fantasy literature are recognizable to many people, but it is the messages and social commentary behind these icons that has captivated readers, and more recently critics, in the past two centuries. Science Fiction and Fantasy appear from the outside to be two distinct forms of literature, and yet the two genres share some similar characteristics and roots. This paradox has inspired much debate over the past century, while the movement itself has grown into a booming publishing industry that shows no signs of slowing.

Critics and historians share widely different viewpoints about the origins of Science Fiction. Still, many have conceded that Mary Shelley's 1818 British novel Frankenstein was the first novel to explore the hypothetical implications of modern science. Most agree that Jules Verne's novels from his "Extraordinary Journeys" series, including Twenty Thousand Leagues Under the Sea and Journey to the Center of the Earth, helped to define the movement. Although most of the early works were published in Europe, in the first half of the twentieth century, Science Fiction and Fantasy literature exploded in the United States. This was due in large part to inexpensive, genre "pulp" magazines like Amazing Stories—which reprinted novels like H. G. Wells's The Time Machine and The War of the Worlds—and to more expensive magazines like Astounding Stories—which helped introduce influential new writers like Isaac Asimov and Robert Heinlein. Science Fiction and Fantasy literature inspired many related movements in film, television, and art, and profoundly influenced the development of science and culture in the twentieth century. The field remains dominated by American authors, many of whom continue to use their speculative creations to comment on current realities.