We’re going by Duke University today but first, a side trip to New Orleans.

I wrote about that river city last week, and specifically about a survivor of Hurricane Katrina named Gralen B. Banks. Banks, I said, lives in a FEMA trailer and laments a rebuilding process that is frustrating and nightmarish.

This brought a number of e-mails from folks advising Banks to quit sitting on his duff and waiting for a government handout. Get a job, they thundered. Be self-reliant.

The funny thing is, Banks has a job, thank you very much. The column noted rather prominently that his business card identifies him as the managing director of a consulting firm. I pointed this out to a few folks, but I’ve yet to hear them respond to that inconvenient truth.

That’s not surprising. Some people have a narrative in their heads where Katrina is concerned: It’s about lazy black folk waiting on the government to save them, incompetent Democratic politicians, poor President Bush, unfairly maligned. Anything you say about the storm gets fed through the meat grinder of that narrative, contradictory fact gets pulverized like gristle, and you are left with a “truth” that validates only what they believed all along.

We all have our narratives. And if we’re not careful, we end up trapped by them.

Which brings us to Duke where, 13 months ago, members of the men’s lacrosse team were accused of raping a stripper. The incident roiled the nation because it had no shortage of narratives. It had class: students at an elite university vs. a working mother. It had gender: male prerogative vs. female vulnerability. And of course, it had race: white vs. black.

Turns out the story had everything except, perhaps, a leg to stand on. Charges were dropped last week after months in which the accuser kept changing her story and corroborative evidence was found to be nonexistent. The attorney general of North Carolina took the unusual step of blasting District Attorney Michael Nifong as a “rogue prosecutor.”

One is reminded, perhaps inevitably, of the Tawana Brawley debacle of 20 years ago when a 15-year-old black girl claimed to have been gang-raped by white men. It never happened – a grand jury said that – but the question of the incident’s actuality is entirely separate from and, some might say, secondary to, the fact that many people believe it happened. It is emotionally true if not really true.

Or as a woman named Collette Wright told the New York Times 10 years ago, “If Tawana Brawley was to get up … and say it was a hoax, I’d say she was lying. We know what happened to her.”

“We know” because it fits the narrative we carry in our heads.

I’m not saying one’s narratives are by definition untrue or without worth. Many of us used the story of 20-something Strom Thurmond having his way with the family’s 16-year-old black maid to illustrate various narratives of class, gender and race; that was fair game. What I am saying is that being too quick to slap a favorite narrative atop an incident can make you miss things you otherwise might have seen.

So the Duke affair is a cautionary tale for prosecutors, pundits, folks standing at the water cooler and others who are inclined to judge guilt and innocence. It requires us to reassess how we know what we know. Is it fact, or just a narrative squeezed through the meat grinder? Truth, or just its emotional equivalent?

Or as an editor told me once: Be rigorous in fact-checking stuff you don’t know. Be more rigorous in fact-checking stuff you do.

I’ve always thought that was excellent advice. I bet the men of Duke would agree.