Understanding Paris: The Cartesian Method

What can a simple ride on the RER reveal about the French approach to problem-solving? Join the author as he heads out to Charles De Gaulle airport one day and encounters a problem in need of a solution.

I was on the RER B light rail north of Paris, and at the last station before a fork in the line a woman’s voice announced our destination. It’s best to pay attention. I was aiming for the airport, but if you catch the wrong train, you wind up in the neighboring community of Mitry-Mory—a town close enough to the runways that you can almost touch the landing gear of passing planes, but a tad inconvenient for boarding.

After the French recording came the British variant, pronouncing Charles de Gaulle as if he were a member of the House of Lords. Then came Italian, the word treno followed by an operatic flourish that morphed Charles de Gaulle into a member of the mafia. And now, because Paris seeks to be cosmopolitan, the same message trundled along in German, announcing in staccato tones that this train was making a beeline for—wait for it—Marne-la-Vallée/Disneyland.

A lanky, blue-eyed gentleman leapt to his feet, his face contracted with confusion. The tone had already sounded to signal the closing of the doors, and in a panic, he now bounded out, his rollerbag flying alongside. The doors slid closed, and we departed.

What just happened? It’s simple: the unfortunate German traveler had found himself transported—not to Charles de Gaulle, but to the Twilight Zone.

There is indeed a Disneyland outside of Paris, but it’s forty kilometers away in a different direction—not even in the same department. Something had gone wrong in the space-time continuum—as though you were driving to Boston, but thanks to a wormhole on the turnpike you ended up in Hartford.

There was, however, an alternative explanation: someone may have simply placed the German recording for the A-line train onto the B-line. Probably the reverse had happened, too, which meant there were now wagonloads of German families equipped with water bottles and fanny packs—the kids sporting Mickey ears—who had just heard that they were being redirected from their holiday to the airport, as though their visas had just been revoked.

Either way, the situation demonstrated a problem, and I wondered how it would be addressed.

In France people pride themselves on what is known as the Cartesian Method. It’s a kind of problem-solving founded on the principal of suspicion. You start with a hunch that things may not be as simple as they seem, which helps you identify a problem. Then you break it into parts, prioritize the steps of your solution, and march forward in the simplest way possible.

The Cartesian method is fundamentally un-American. I, for instance, address problems the way you might swat at flies, just trying to make them go away. The French tend to dissect the fly. They try to understand its motives, and then they figure out how to discourage it from pestering you.

I’m not trying to say one method is better than the other. There’s a time and a place for each. When my friend Guy spends half an hour studying a wine list in a restaurant, I tend to think we could do with a little less dissection. On the other hand, if your country is contemplating the invasion of another nation, probably you don’t want to resort to the swatting impulse. I don’t know. Maybe that’s just me.

Because I head out to the airport every now and then, I was able to track progress on the announcement problem. Two months later I found myself back on the same train, and when we reached the station at the fork, I listened. Passengers who were French, English or Italian were heading to Charles de Gaulle, but our German fellow voyagers were still traveling to Disneyland. This time no one in my car seemed to care, but as the train started forward, I again noticed several blond people with suitcases standing bemused on the platform.

Clearly the officials in charge hadn’t yet reached the first step of the Method: they hadn’t recognized the presence of a problem.

In the course of experiments, I believe scientists should remain simple observers. You don’t want them poking at things in the petri dish and adding their own germs to whatever dread disease they’re breeding. But it occurred to me I might be able to play the hand of God, just to put things in motion. So I went to the website of the RATP—the transit authority—and found a page inviting feedback. It bore an invigorating title: The RATP is listening to you!

I filled out the form, but when I clicked on the submit button, the link was dead. At first I found this irritating, but then I was impressed with the technology. Haven’t we all developed mechanisms for pretending to listen while remaining deaf to suggestions? They had reproduced with exquisite fidelity my own reaction to people’s ideas for my self-improvement. As artificial intelligence continues to refine its miming of human interactions, we should expect more features of this sort.

So it continued. Many months passed. Two years later the B-line trains were still sending Germans scrambling onto the platform, laden with suitcases and duffels. I managed to help one or two, but you couldn’t save them all. It was a weird kind of Sophie’s choice.

Worse yet, I worried I was seeing the same people again and again. After all, having bailed out of the B-line, wouldn’t they just try the A-train? And then, after a couple days at Disneyland, they’d realize it wasn’t an airport, so they’d try the B-line again, setting the whole process back in motion. It had been a long time since I’d read Dante, but I was pretty sure there was a ring of hell just like the RATP.

I tried the website again, and now the submit button worked. I filled out the form and soon received an automated reply assuring me that my input was of the utmost importance. I understood: they had improved their technology, now able imitate the kind of “uh-huh” I emit whenever my mother tells me I should make something of myself.

Still, I knew it was just a matter of time before they figured it out, and once the problem was identified, the dissection of the fly would begin. The only question was: what solution would they cook up? I tried to put myself in Descartes’ shoes. Probably they would just reverse the recordings: some RATP worker would trudge from the A-line office to the B-line with a thumb drive in his hand. But what if the corresponding recording had been lost? Maybe they would cut the words “Marne-la-Vallée/Disneyland” from the German tape and splice in the Italian-accented
version of the airport. Or else they’d approach one of the Germans hanging about the train stations—they were so abundant now—and recruit them to re-record it.

Months later, the misdirection continued. I wondered if it was somehow deliberate. There has always been a French-German rivalry, after all, and although the RATP isn’t known for practical jokes, there’s always (or often) a first time. Another possibility: the recording was part of the government’s plan to stimulate the flagging French economy—starting with taxi drivers.

And then it happened. I was headed out to the airport one autumn morning huddled on my seat, drifting at the edge of sleep. The train stopped at the fork, and the announcements began. First came the seductive tones of the woman in French, easing our passage. Next it was the nasal rendition of that very erect Brit. Then came the impassioned Italian, reveling in our imminent arrival at Charrrrles de Gaulle.

I held my breath as the silence stretched.

The tone sounded and the doors closed. We tipped into motion.

Such brilliance. I hadn’t even seen it coming. They had out-Cartesianed Descartes, finding the simplest solution of them all. After nearly four years, the German recording had been cut.