There's many forces that can "drive" a story, but my pet theory is that there's three main ones: plot, character, and theme.
If plot is what's driving a story, the first thing the author thought of while writing the story was probably, "Wouldn't it be interesting if X happened?" Shakespeare's stuff, for example, is pretty plot-driven: you're watching because you want to know what happens when two star-crossed lovers fatefully meet, or you're wondering what a Danish prince is going to do when everyone around him starts getting offed.
If character is what's driving a story, then the character, or the dynamic between some set of characters, is what the author was probably thinking of when they first conceived the story. Nabakov's Lolita and Twain's The Adventures of Huckleberry Finn are both character-driven: you're reading Lolita because the inside of a pervert's head is a fascinating place, or you're reading Huck Finn because Huck is such an endearing, fully-realized character. (Or, random anime example: Cowboy Bebop. The show's "plot" is only five episodes; everything else is just character studies.)
Now, theme. Hrm.
Most of the time, I would tell you that it's folly for an author to approach a story from a "theme"-y angle. It's the kind of story that happens when an author starts by saying, "I want to explore the isolating effects of technology on people in the 21st century," or, "I want to tell a story about how the boundaries between people are more fluid than they seem," or whatever.
The problem is that there's no motor driving this sort of story along. A reader doesn't frantically turn pages because they want to know what happens next in the theme-they want to know what happens next in the plot. And a reader doesn't fall in love with a theme the same way they can fall in love with a character.
And a lot of the time, when theme is what's driving a story in a writing workshop, you can tell-because the story is filled with some lovely symbolic anecdotes, and perhaps some nice imagery, but the characters aren't very interesting, and not a whole lot happens, so you're bored by page three. Done very poorly, that story can start to feel like an Aesop: a plot so stagnant it could be summarized in a tweet, and characters so flat they may as well be called Mouse and Lion.
I thought for a long time that, if you're writing a story and you're thinking about theme first, you're Doing It Wrong ™: theme is what naturally arises when you've got a strong plot, or a solid cast of characters, but if you're thinking about theme first, then you're trying to slap the roof on when you haven't even built your foundations.
But Miyazaki, as far as I can tell, works theme-first. And he does so powerfully.
I'm basing this off of two project proposals of his I discovered: the proposals for
Spirited Away and
Princess Mononoke. Though I wasn't able to find much information accompanying these documents, they appear to be his "pitches" for those projects: him explaining what exactly the movies were going to about.
And neither of them mention very much about characters or plot at all. It's just theme. Like this, from the first paragraph of his Spirited Away proposal:Today, the world has become ambiguous; but even though it is ambiguous, the world is encroaching and trying to consume (everything). It is the main theme of this film to describe such a world clearly in the form of a fantasy.
Or this, from his Princess Mononoke proposal:We depict hatred, but it is to depict that there are more important things.
We depict a curse, to depict the joy of liberation.
It's possible that he was only emphasizing the themes in these project proposals because that's what the studio wanted to see, and he was really wanting to make something intensely character/plot-driven. But, based on the final products, I'm inclined to think he really did think about these in a theme-driven way. Spirited Away isn't really about Chihiro or Haku so much as it's about what it's like to try and find some measure of strength and autonomy in an unfriendly world. Princess Mononoke is pretty plot-y, admittedly, but it's also deeply concerned with the irresolvability of conflicts between man and nature, and with the conception of "beauty" in a world of violence and brevity, and the plot is (arguably) subservient to those themes.
I have a couple ideas for why the theme-y approach works in these contexts:
* Maybe it's easier to get away with theme-driven stories in a visual medium. After all, there's a difference between the sort of story you can tell with two hours of colorful animation and the sort of story you can tell with several hundred pages of prose. But I think there's probably theme-driven books, too. The first one that comes to mind is Le Guin's A Wizard of Earthsea: the book certainly has a decent plot and cast of characters, but the main thing you remember after reading that book, even years later, is the ending-which I'm not detailing here, because spoilers, but suffice to say it is pretty damn theme-y.
* Maybe, even if theme was foremost in his mind when he conceived of the stories, Miyazaki made characters and plots that were so strong that they ended up driving the story, instead of those themes. This may actually be the case; I'm undecided as of yet.
* Maybe these distinctions I'm making are wholly arbitrary-maybe all stories all have varying degrees of emphasis on plot, character, and theme, and trying to determine which one is "driving" the story is the sort of academic exercise that abstracts away necessary, messy details. This may also be the case; I have been known to overthink things.
* Or-maybe thinking "theme first" is a valid approach to story-making, albeit a very difficult one. And, if this is the case, perhaps I should be more receptive when theme-y story ideas come to me, rather than tending to disregard them as abstract nonsense from the outset, since evidently at least one guy is able to shape those ideas into good stories.