The trolley is coming, tra la tra la.
  • Trebz/Wikimedia Commons
  • The trolley is coming, tra la tra la.

When I first heard about the trolley problem a few weeks ago on the radio, I must have missed a few details.

The subjects in a research study were given a set of choices: First, imagine yourself alongside a trolley track. Just ahead, a spur branches off. A trolley out of control is hurtling toward the junction. On the spur track there’s one person unaware of the oncoming trolley. On the main line there are five. The trolley will surely run into the five, killing them all. Or you can flip a switch and shunt the trolley onto the spur and only one person will die. What would you do?

Most subjects said they’d flip the switch. Very well, they were told, but now suppose yourself on a bridge that crosses the track. A fat man shares the bridge with you. You could shove him off the bridge and onto the track, which would halt the trolley, costing him his life but saving five others. Or you could let the tragedy take its course. Most of the subjects said they’d let the fat man be, even though—and whoever was laying out the trolley problem on the radio was emphatic about this—the two situations were essentially the same: one life versus five.

So why the difference? What I heard on the radio was that the people who would flip the switch but let the fat man be could not say why. They were obeying no principle they could put their finger on.

That’s ridiculous, I thought.

Yes, I’d have flipped the switch. I also would have screamed Get the hell off the tracks! If I had my wits about me I might have flipped the switch and then flipped it again while the trolley was rolling through the switch, hoping to derail it before it killed anybody.

As for the fat man . . . chances are he wouldn’t allow himself to be easily pushed. Chances are while we were tussling the trolley would roar by underneath. And why would I even think his bulk would stop the trolley? Why wouldn’t the trolley hit him, push him aside, and keep on going to kill five more?

So this was my response to what I heard on the radio—no, I wouldn’t push the fat man. But I could tell you why. I could tell you that the “spur” variant and the “fat man” variant of the trolley problem were not the same problem differently dressed out. They were fundamentally different.

But Sunday I came across the trolley problem in the New York Times Book Review, where it was discussed in a review of two new books: Would You Kill the Fat Man?, by David Edmonds, and The Trolley Problem; Or, Would You Throw the Fat Guy off the Bridge, by Thomas Cathcart. Apparently I’d missed some details.

As reviewer Sarah Bakewell describes the problem’s hypothetical situations, it’s even more unworldly than I’d already thought it was. The people in peril can’t get off the tracks because they’re tied to the tracks! The fat man can be effortlessly pitched off the bridge. And when he is, his bulk will stop the trolley. My first thought when I came across these stipulations was that the trolley problem asks for our visceral reaction to a situation we viscerally know is preposterous.

Is it good science to leave the real world so thoroughly behind? Possibly not.

“Assaulting the Fat Man just feels wrong: our instincts cry out against it,” writes Bakewell, summarizing what the books have to say. “Nothing intrigues philosophers more than a phenomenon that seems simultaneously self-evident and inexplicable.” If this accurately summarizes what the two books have to say, they must be oblivious to the hidden hand of common sense in guiding our response to ethical quandaries. There is nothing inexplicable about believing you wouldn’t do something that—if you did it—almost certainly wouldn’t work.

Bakewell tells us “trolleyology” is part of the philosophy course taught to cadets at West Point, as military officers need to know how to think about hard choices, consequences, and collateral damage. That’s fine, but do they understand that some tests that may not plumb the depths we’d like to think they do?

Should you kill the fat man? Follow this link and take the quiz—a series of questions that ask how you’d respond to a version of the trolley problem. (Here it’s a runaway train threatening a total of six persons who simply cannot get off the tracks in time.) After a series of questions that ask in a general way about your moral sensibility, the quiz gets down to brass tacks.

Would you divert the train onto the spur? And, when you’ve answered that: Would you push the fat man off the bridge and stop the train—or would you “allow the train to continue”?

You can’t protest the question. And you can’t skip it. If you try to, a message in red letters shows up on the screen: Please make a choice!

Are West Point cadets also taught how to dig in their heels and insist those aren’t the real alternatives?