Kristen Lamb is an intelligent and eloquent writer and blogster. You can see her blog here.
She does this thing that many writers do, which is to describe the methods and means of storytelling and writing via metaphor. A sensible mode of instruction, of course. Tried and true as a thing that's been tried a lot and determined to be pretty true.
Thing is about metaphor, though, is it's like describing things with smells: when done aptly, has the power to reach into people and make them remember their childhood like the smell of vomited summer squash (a traumatic memory of mine, at least).
Her metaphors work well usually. She describes plot as the story's bones and she describes the antagonist as the story's engine. I like both of these ideas, not the least because they imply that stories are a kind of diesel-punk skeleton monster, tortured to action by the very thing that gives it life, which sounds cool (and I'll be logging it away as a thing to write about someday). There's a metaphor she uses that I don't think works, and that's something she says about character.
Characters, she says, are like your story's heart.
I don't think so, and this is why:
In modern, western culture, the heart does two things: it provides (figuratively) provides emotion, and (literally) maintains life. I agree that characters have a part in giving stories life and emotion, but I don't think that those are a character's primary functions.
I think that a better metaphor to describe characters in stories would be fingers. This is why: if the diesel-punk skeleton from above has a heart, but no fingers, then it's an interesting idea, but it doesn't do anything. With fingers, the diesel-punk skeleton has the ability to move around and change things.
In a reductionist practice of analysis, stories need to move around. They need to misdirect, conjure, scratch, play music, make signals, conduct, strike out...they need to move. Characters provide movement--they're interactive--they do things.
I do not disagree that the diesel-punk skeleton/Antagonized Plot requires some sort of emotional center and maintainer of life like a heart; I also don't think that the fingers/characters would be divorced from the emotive and living functions of the heart. The characters, I will forever contest, express ever significant part of stories--the "heart" included. I just think that the heart of stories is kept somewhere other than in its characters.
I think that the heart of stories is kept in the reader and the writer, but I'm not sure how to describe that, so I'm going to think about it for a while before I try to explain.