It’s fun to play with thoughts, to riffle through ideas, don’t you agree? Take ‘thought experiments’ for example -think up a problem, set some parameters to confine it and see what your brain, unconstrained by external reality, comes up with. It’s almost akin to the Scientific Method some would argue: ask a question; form a hypothesis about it; make a prediction based on the theory; test the prediction; and finally, come to some conclusion. But is it? Can a mind sitting quietly by itself in an armchair, circumvent the need for external reality?

Ever since I first heard it, I have felt uncomfortable with ‘the Trolley Problem’. There have been several iterations of it over the years, but by and large it consists of a runaway coach on a track that is approaching a switch. Down one track is a single person, whereas down another are several people. The coach cannot be stopped, the person (or people) cannot get out of the way, but the switch can be thrown to direct which track is used. The question, of course, is which track to use -either track will result in death.

What does the choice of one track or the other say about the person who has to decide? About their morality? About ethics? About anything, really? It seems far too monochromal for my liking. And, unlike its real-life cousin, by definition a thought experiment cannot really be subjected to any rigorous objective analysis. It’s more like an experiment done in a lab where all parameters are carefully controlled, unlike what would happen in the real world.

But for years I’ve wondered whether my discomfort was misplaced. After all, Einstein used thought experiments. My concerns, like an unused city lot, lay fallow until I wandered into an essay by James Wilson, a professor of philosophy at University College London: https://aeon.co/essays/what-is-the-problem-with-ethical-trolley-problems

As he writes, thought experiments are ‘short hypothetical scenarios designed to probe or persuade on a point of ethical principle. Such scenarios are nearly always presented context-free, and are often wildly different from the everyday contexts in which ethical sensibilities are formed and exercised… Even when scenarios are highly unrealistic, judgments about them are thought to have wide-ranging implications for what should be done in the real world. The assumption is that, if you can show that a point of ethical principle holds in one artfully designed case, however bizarre, then this tells us something significant.’

Sometimes, however, when considered as things that might happen in the real world, we can envisage other conditions that would invalidate, or at least complicate, any conclusions drawn in the thought experiment. We know too much, as it were. ‘Thought-experiment designers often attempt to finesse the problem through an omniscient authorial voice that… is able to say clearly and concisely what each of the thought experiment’s actors is able to do, their psychological states and intentions. The authorial voice will often stipulate that choices must be made from a short predefined menu, with no ability to alter the terms of the problem. For example, the reader might be presented with only two choices, as in the classic trolley problem: pull a lever, or don’t pull it.’ Exactly.

So constraining the choices limits the possibility of novel approaches to the stated problem. ‘Imaginative ethical thinkers look beyond the small menu of obvious options to uncover novel approaches that better allow competing values to be reconciled. The more contextual knowledge and experience a thinker has, the more they have to draw on in coming to a wise decision.’

But there are at least two other difficult challenges with thought experiments: internal and external validity. ‘Internal validity relates to the extent to which an experiment succeeds in providing an unbiased test of the variable or hypothesis in question. External validity relates to the extent to which the results in the controlled environment translate to other contexts…[but] the very features that make an environment controlled and suitable to obtain internal validity often make it problematically different from the uncontrolled environments in which interventions need to be applied.’ In other words, the world just doesn’t work like that.

I remember trying out the Trolley Problem on the guys who meet for coffee some mornings in the food court. I wondered if they felt the same unease with it as I did.

“So, which track are you going to switch the trolley onto?” I asked, after giving them a brief summary of the thought experiment.

Burt put his doughnut back on the paper plate, and wiped some sugar off his cheek. “It’s so obvious, G -I’d ring the bell. All trollies have bells, eh?”

“But what if the workers on the track don’t hear it…?”

Burt rolled his eyes, as he brushed a lock of his paper-white hair off his forehead. “I’d keep ringing it. The workers would hear it when it got closer…”

“But suppose the workers are tied to the track.”

Burt glared at me for a moment. “You didn’t say that. And anyway, why would they be tied to the track? That’s a bit Little Orphan Annieish, don’t you think?”

I decided to relent a little to make it more -what?- real worldy. “Okay, let’s say they’re just deaf…”

Burt was clearly unmoved by my compromise. “Still…”

Jason, who had been quietly munching on a bagel put his hand up.

Burt sneered at the hand. “You’re not in school, Jas…”

Jason blinked and lowered his hand, and then glared at Burt. “Whatever. Anyway G, you said they were working on the track. They’d be able to feel the vibrations on the rails from a moving trolley, so that would warn them to get out of the way.”

I had to sigh; the guys were not really getting into the spirit of the ethical problem I’d offered. “I don’t know how much warning that would give, but let’s say they weren’t actually standing on the rails…” I had to think quickly here. “Let’s say they were on the ties between the rails then.”

Arthur, who had been teacher before he retired, sighed loudly and shook his head. “You folks are missing the point.”

Burt took a big bite from his doughnut. “The point being…?” It was hard to distinguish word from doughnut, but Arthur ignored the sounds.

“It seems to me the problem is bimodal.”

I smiled and nodded my head at him -finally somebody understood the ethics at stake. “Correct,” I interrupted, “There are two choices: the left track or the right track -several deaths, or one death. Which one would you choose, Art?”

He glanced at me quizzically. “I didn’t say there were two choices; I said bimodal: values occurring most frequently in the data set we were given…”

Jason, Burt and I stared at him, but it was Burt that summed it up. “You had too many cookies, Art…?”

It was Arthur’s turn to roll his eyes. “What I mean is that we have to consider two data streams that affect the choice of track…”

“Too much sugar in his coffee,” Jason whispered to Burt.

Arthur ignored them. “First of all, there’s the trolley driver. He would be ringing the bell, of course, but presumably to be allowed to drive the trolley, he’d have been expected to know about things like the switch signs that indicated which track was open.” He stared at me. “Would that not be the case?”

I shrugged, but I had to agree with him.

Then a wry smile appeared to hover tentatively along his lips. “And then there is the person whose responsibility it is to work the switches.” His smile softened briefly. “A very important job, as you can imagine.”

None of us disagreed. I was more interested in where this was leading, though.

“So,” he continued, “We can assume that the switch person knows that the driver has to have some expertise in reading the switch signs…” He looked at each of us for a second to see if we were following him. Nobody moved. “Therefore, the switchman flags the approaching trolley to let the driver know he understands the trolley is out of control, and then sets the switch only at the halfway position. The driver would see this as an uncompleted switch and realizes it will derail the trolley, so he jumps clear.”

Arthur sat back in his chair this time with a big sloppy grin on his face. “So, nobody dies. Problem solved…”

I suddenly remembered that scene in Shakespeare’s Hamlet: There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy.

I wonder if Hamlet could have resolved the Trolley Problem as quickly as Arthur, though.