A friend told me this afternoon that sometimes he agreed with the authors who said that they wrote literature, not science fiction, that science fiction was more about the landscape of the story than the genre. Where it takes place, not what happens there.
This brought up a way I've been looking at fiction for a long time, which I think may be a useful distinction. I've always been of the opinion that there are two kinds of fiction genres, landscape genre, to use my friend's term, and plot genre. Landscape genres are about when and where a story takes place, and the sorts of stories those locations allow -- science fiction and fantasy, historical fiction, and westerns. Plot genres are about specific types of stories and can take place pretty much anywhere -- mysteries, thrillers, adventure stories, and romance. Those are the major ones, although I'm sure there are more, and, of course, literary fiction is a plot genre for the purposes of this distinction, too.
This is what allows for so many kinds of romance fiction, for instance. Historical, paranormal and futuristic (the romance community terms for fantasy and science fiction), contemporary, and so forth. Romance absorbs them all, because romance is about the story of falling in love.
My favorite author, Lois McMaster Bujold, does the the inverse with science fiction and fantasy. Her Vorkosigan series, which is science fiction, contains mystery, romance, and adventure stories among its volumes. They're all science fiction because of the setting and landscape (in the broadest sense) in which they take place.
I also think this is what makes cross-genre books work, and gives us such a variety of possibilities.
For instance, Repeating History is historical fiction with fantasy elements, which are its landscape genres, but it's also an adventure story and a romance, which are its plot genres. How would you break down what you're writing in this way? Does this distinction work for you? Are there examples I'm missing where this does not hold true? Or am I simply the last person on the planet to come up with this concept?