Science Fiction in the Twentieth Century is the first book to challenge the traditional approach to science fiction as a series of texts and authors. Science fiction is identified as a cultural phenomenon whose ideas and imagery, through books, films, television, computer games, and children's toys, have become part of the everyday language of the late twentieth century.

Edward James traces the development of science fiction as a distinct genre from 1895, the year of publication of H. G. Wells's The Time Machine, through the growing American domination of the field in the 1930s and 1940s, to the emergence of cyberpunk in the 1980s.

A peculiarly twentieth-century genre, science fiction has tried to make sense of the rapidity of technological change and the impact which science and technology have made on our society. By imagining other worlds and possible futures, the genre allows us to view our present-day situation with greater detachment and perspective.