"If you set out to tell a story you quickly find that you cannot go just anywhere."
But that's the art of it-- finding freedom in the constraints, keeping the imagination wide open even as the words multiply on the page.
... I was thinking of something else, really--not the matter of defining limits, the aesthetics of form. Rather, something closer to the grammar of narrative, if you will. If you write 'which' or 'how' or 'when' at the beginning of a sentence, those words won't be relative pronouns. They'll be interrogative pronouns, and the sentence that follows will be a question. If you begin a story with a certain tone, style, voice, the narrative that unfolds will have to 'fit' that tone, style, voice. Changing it midstream will be jarring. If there is a dramatic change in the personality of a character, you will be expected to demonstrate cause. Nothing remarkable about this observation: pointing out the obvious--until you start to think about how this affects your subject--the subject that is more than words, more than language, the subject present before you began to write, that impelled you to begin to write. It's what you want the words to be true to--even if that 'something' is not a thing, but a process, a record of a conversation. If you're a "realist," you think in terms of representation, mimesis. You imagine you are guided by the laws that govern in the real world--but that's the joker in the deck: Reality is not made of rules and laws--certainly not as they function in a story; in fiction, these rules are simply conventions we use. Writer's of "realist' fiction follow them because that is what readers expect.
The moment you begin to write (and I think writing is different than speech... though we sometimes speak as though we were writing)... the moment you begin to write, conventional expectations threaten to take over, to high-jack the subject, the "real" subject (forgive me... I don't know what else to call it at this point). I think this is what makes endings so often problematic. The writer gives up--surrenders to the conventions, resigns authorial responsibility. This is related to what I was thinking about in my post on ads and propaganda.
I realize I'm babbling... these are the kind of thoughts that run through my mind when I go to bed, that keep me awake wondering what it is that's gone wrong this time in my novel, wonder how I'm going to rescue it from looming disaster.