First–my apologies for not checking my facts more carefully regarding the plot of Pride and Prejudice. I do definitely agree with you about where Keeping the Castle fits in your taxonomy. In fact, at the risk of putting my foot into it again, I could say that I think Keeping the Castle also owes something to Emma (I’m thinking here of Althea’s matchmaking tendencies).
As a side note, there is a blurb on the cover of KTC that says “Fans of I Capture the Castle will love this delicious confection.” Now there’s another book I know and love well, and I would have to say that other than the crumbling castle, the marriageable young ladies, and the wealthy neighbors, there really isn’t much similarity there. I Capture the Castle, as much as I loved it as a young teenager, is not at all a “confection” and Cassandra is a very different young woman from Althea. I would have to have a serious readers’ advisory conversation with someone who liked Keeping the Castle to find out what the appeal factors were before I recommended I Capture the Castle to her.
But your taxonomy did bring two things to mind. First, I really like your distinction regarding novels based on fairy tales and myths–the “continuous dialogue.” This is why, I think, those stories are evergreen–because each new one adds something to the ongoing conversation. We find Cinderella stories, for example, in different cultures, and each version tells us something about the culture, as well as telling us a rags-to-riches tale. And obviously, putting these stories in different times and places conveys as much about the time and place in which it was written than about the tale itself.
Second, your fifth category (books that are “not strictly adapting or remaking earlier works but, through allusion and thematic content are reliant on them to some extent”) as well as the one about fairy tales struck home with me as I just finished reading Some Kind of Fairy Tale, by Graham Joyce. It’s a novel about a 15-year-old girl, Tara, who disappears, then turns up 20 years later looking not much older and saying that she lived with fairies (well, she doesn’t use that term) for six months.
Knowing some stories like Tam Lin and something about folklore in general is useful but not essential in following the story. But that’s obviously not what Joyce is trying to do here. In fact, I thought one of the most interesting aspects of the book was the way the psychiatrist who treats Tara takes everything she says and puts it into modern psychological lingo. It made me think about Frances and Elsie in The Fairy Ring and how they might have been treated if they had lived a hundred years later!
Anyway, I did like your taxonomy, and it does help me think about books like The Humming Room and Keeping the Castle. I suspect there may be more categories (I was waiting for you to bring up Shakespeare), but I’ll leave that to you and your inner (or not-so-inner) lit geek.