Some years ago, while writing The Heart of the Sea, I asked Karen and Ron to read drafts of the story. They liked the early chapters, which encouraged me to keep plugging away at it. (Getting a complete first draft took three years!) Near the end of the story I introduced a twist to the plot, partly because I had imagined a wonderful character who, I thought, needed to get into print. And the new wrinkle to the story gave me a neat way to wrap it up.
I won't describe the plot twist. Karen didn't like it, and Ron disdained it in very strong language. If I used it, Ron said, it would ruin the story. The Heart of the Sea is a fantasy adventure story; adding a science fiction ending would spoil everything. The new character, however much I liked her, had to be removed.
So . . . The Heart of the Sea got a new ending, which Karen and Ron approved. Eleanor Roosevelt Urquhart got a story of her own. (The name alone makes you want to know her, right? Someday, Buying the Bangkok Girl will find a publisher.) And the whole episode illustrates the principle of "fitness."
We love fiction partly because it puts us in an imagined world. A story may be set in a familiar place, but it records imagined events. One might think that since the events are not real, an author could write anything he wanted. But he can't. There has to be fitness between the parts of the story.
I am not now talking about the moral ground underlying all stories. I wrote about that in an earlier post. See my April 3, 2012, post, "The Limits of Creativity." Instead, I am pointing to a need for the events, characters, and themes of a story to cohere. An author can put angels and spaceships into his story; C.S. Lewis had both in Out of the Silent Planet. But once you have angels, the plot can't progress on strictly materialist lines. One of Lewis's characters is a strict materialist, but the story shows him to be deluded for just that reason.
Suppose someone wrote a story about a sadistic murderer. For two hundred pages, you read of death, dismemberment, blood, and viscera. But then, from pages 201-265, the story consists of the murderer discussing the roses in his garden with his neighbor. The end. Now this would be a shocking story, not because of all the gore, since readers nowadays are used to it, but because of the lack of fitness. In fact, such an extreme lack of fitness would push most of us to conclude that the author was trying to make an existentialist or post-modern philosophical statement. In other words, we would impose on this bizarre story some explanatory scheme--from the outside, not really part of the story.
Fitness is not just a feature of literature. Human existence has narrative form. Esther Meek, a philosopher I have been reading this summer, says that all human acts of knowing ought to be understood as narrative acts. When we understand something, we indwell lots of particulars in a subsidiary way in order to focus on a pattern in a conscious way. Coming to see/understand the focal pattern transforms our earlier knowledge of the particulars. And since we are temporal, narrative creatures, coming to see/understand orients us to the future. We expect the world to "fit" with what we have come to know, even if that fitness often surprises us.