What's literary fiction? What's science fiction?
My father's been reading Alan Lightman's Einstein's Dreams, and tells me he found Einstein's apparent lack of filter, lack of ordinary sense of the reasonableness of ideas, very interesting. He said he thought every high school student should read it, if only to see the value of being so free, mentally, from ordinary constraints. When I think of Lightman, I think mostly of his book Origins, which I enjoyed very much, and of attending a small, awkward reading of Good Benito. I'd been surprised at the reading; the quality of the prose didn't seem to me very good, didn't seem to me to reflect the man's intelligence or subtlety of mind, which I think are easy to see in his nonfiction.
My father thought I was being a pain in the ass. He told me to get past the quality of the prose and look at the ideas, which is something I've been doing lately in reading recommended SF. It occurred to me that most of the conversation I've heard praising SF has indeed been about the ideas, often complex and powerful ideas, and often with a sense of clarity and cool interrogation that makes me think hypothesis. Poetry, a literate, sustained, fine-art sense of language and what it can do, doesn't seem to be a requisite part of the show, and I think it is very much in what I think of as literary.
There are enough disgruntled blog discussions of "what is literary" that I suspect it hasn't got a long life ahead of it as a genre. (See here and here, for example.) The question "what is art", though, attracts the same sense of frustration and annoyance, and I don't think it's going away. Wikipedia's prudent entry points out that the definition of "literary merit" is important legally, but otherwise doesn't want to get involved.
I wonder if the relative importance of ideas and poetry are real differences between literary and SF, and a reason why there's this low-grade antagonism. I wonder if champions of each are simply blind to what the others see as valuable.