"You have to have two stories to have a story."

In The Believer Book of Writers Talking to Writers, Grace Paley talks (with Nell Freudenberger) about her short story "Somewhere Else", which is set in both China and the Bronx:

You know - the thing is this: if I just wrote about China, it would be a report, more or less. You have to have two stories to have a story. That's what I've been teaching my classes. You need two stories, at least. And for a novel, of course, you probably need more. I couldn't find the other story. I mean, I wasn't conscious of this; my idea that you need two stories came long after I wrote everything. I said, "Oh, that's what I was doing."

I had never thought of story-writing that way, but it makes perfect sense. You do need two stories to make a story; otherwise, it's just a sketch (or, in Paley's words, a report). Unless you have conflict, you don't really have a story. It doesn't have to be two parallel story lines with separate protagonists that ultimately collide; instead, it can be two aspects of a single protagonist: past versus present, internal versus external, work life versus family life.

Thinking about the story collection I'm working on right now (working title: Marshland), I can already recognize that the stronger stories are indeed comprised of two stories, and that the weaker ones may have an interesting premise but are flat because the conflict (those two stories) is absent.