Genre writers of ambition sometimes start to wonder why the rest of the world does not take them as seriously as it should. "Isn't my work as valid as some damn sensitive coming-of-age story?" they wonder. "Isn't a charge of Comanches or a crash landing on an ice planet or a body discovered face down in the koi pond as significant an event as an adulterous encounter during a grant-funded year abroad?"
I'd say they are, but not because all of those things exist in some kind of common literary space. I think there really are genre boundaries, because genres are communities of practice, sets of agreed-upon techniques and tropes, and market segments aimed at audiences with certain already existing characteristics. They exist, not in the same sense the chair I'm sitting in exists, but certainly as definitely as, say "left-liberal urbanites with a need to feel compassion" or "Red Sox fans" or "model railroad enthusiasts" exist.
There is lately a bit of buzz about this in my own field, shown, in one instance, by a book edited by my friends John Kessel and James Patrick Kelly, The Secret History of Science Fiction, ably reviewed by Paul Witcover here. Is science fiction part of a continuum of literature, or is it somehow separate?
Is "Thai food" part of the continuum of food, or is it somehow separate? Is "big band swing music" part of the continuum of music or....etc. You get the idea. And I think you already know my answer. These are communities of practice, sets of agreed-on techniques and tropes, and productions that appeal to a certain market segment. Many of us like responding to our fellow writers, like being able to test ourselves against great writers of the past, like having some standard techniques available to us so that we can focus on experimenting in other ways, and like knowing something about who our audience is and what it cares about. These are not pathetic weaknesses. In genre there is strength.
I was going to start this entry writing about Lonesome Dove, which I just finished--Western being another genre. Some other time!