It’s a thought experiment about killing, death and an out of control train, but does the trolley problem really get to the crux of how to make an unpleasant life and death decision?
Devised by the philosopher Philippa Foot, the scenario involves a trolley (a kind of tram powered by an overhead cable) travelling along a track on its usual journey until you realise that it’s out of control.
The driver can do nothing to stop it or slow it down, and to make matters worse, there are five people ahead standing on the track who don’t know they are in danger.
It seems like there is nothing you can do except watch five people get hit by the trolley and die.
However, there is one choice in this thought experiment; you can flick a small switch which can divert the train onto another track, allowing those five people to live.
The trouble is that on the second track there is one person standing on that track who will be hit and killed by the trolley if you flick the switch.
Do you flick the switch or not?
Children interviewed for kids’ podcast Short & Curly, said the most important thing was to save the largest number of people possible.
“Can’t you just flick the switch so the train topples over and that would save all the people from dying?”
“Five lives are greater than one, so why would I sacrifice five lives just to save one, even if that person was my best friend that’s five lives and you’re only one life so I would rather have you gone.”
“I would want to learn who that one person was and I would write a letter to their family and explain why I had to do it.”
Some wavered a little, wondering whether it would be different if you knew the people about to die and if it would also make a difference if you loved them or hated them.
One child said she would kill that one person, even if it was her friend, because saving the greatest number of lives was always the top priority.
Much like some adults, there were a smaller number of children who questioned whether to do anything at all.
They didn’t want to flick the switch themselves because they saw that action as essentially killing someone, which they didn’t think was ever right.
In their mind, doing nothing might be morally OK because those five people would have died anyway, had you not been there in the first place.
Some kids got upset at this, though, and countered that it is never OK to do nothing when people’s lives are at stake.
Does the trolley problem help make decisions?
There have been versions of the trolley problem involving pushing a large man off a bridge instead of flicking a switch, and versions where you take the perspective of the train driver, a passenger and a bystander going for a walk near the train line.
So is the trolley problem useful in helping us make decisions in an emergency? And can it help us work out what sort of person we really are deep down?
City College of New York philosophy professor Jennifer Moreton said people should think about the action taking place.
“One way is that you’re killing someone, but that doesn’t seem quite right,” she said.
“What you’re really doing is trying to save the five people and it’s a side effect of saving five people that one person dies.”
“This is known in philosophy as the doctrine of double effect, as what you intend to do is to save five lives, but it’s a side effect that you kill one person.”
Advocates of the trolley problem have said that the thought experiment acts as a kind of ethical workout, strengthening our theoretical ideas about what we value and what we think our duties are in life, so when a crisis appears our moral muscles might kick in and help us do the best thing possible.
The trolley problem vs driverless cars
As we move into the world of driverless cars, these questions remain relevant, as cars will need to be programmed to make split-second decisions during an accident.
Do we program the car to prioritise the safety of the greatest number of pedestrians or do we put the driver’s life and that of their passengers first?
The thing about the trolley problem, of course, is that there’s no right thing to do — you need to make what you think is the best choice in a terrible situation.