We asked you to vote on whether it would be right to take one life to save five, and other dilemmas. Here's what you decided... and what it means.
On Tuesday the Magazine presented four ethical dilemmas that provide classic "thought experiments" for philosophers.
Many thanks to the thousands who took part; the results help shed light on what has, until now, been an empirically nebulous area of ethics.
Despite the methodological limitations of the study, I have little doubt that philosophers will refer to this large-scale experiment to support or refute their claims.
1. THOMSON'S VIOLINIST
You wake up in hospital, next to a world famous violinist connected to you with various tubes. You've been kidnapped by the Music Appreciation Society. Aware of the maestro's impending death, they hooked you up to the violinist. If you stay connected, he will be totally cured in nine months. You are unlikely to suffer harm. No one else can save him. Do you have an obligation to stay connected?
The results: 25 percent said yes, 75 percent said no of 57,779 votes cast.
As expected, most of you believe it's morally acceptable to disconnect yourself, but a significant minority think otherwise.
It would be interesting to find out how you selected your answer. Is there a duty to save the violinist? Does he have a right to life that would be violated by disconnection, or does he just have a right not to be killed? Is unplugging yourself killing him or letting him die, and does it actually matter morally which it is?
I suspect many will say that you are not killing him, but letting him die. For some people, this is how Thomson's case differs from abortion. When you abort a foetus, you are not just letting the foetus die. There is usually an intention to kill the foetus, whereas there's no intention to kill the violinist.
Those who remain connected need to confront the following issue: as I write, thousands are dying of preventable diseases in Sudan. The World Health Organization says that funds are urgently required. You could save some of them, just like the maestro, by giving up far less than nine months. Does consistency require you to make some personal sacrifice to others whose lives could also be saved by your actions?
2. THE RUNAWAY TROLLEY CAR
In the path of a runaway trolley car are five people who will definitely be killed unless you, a bystander, flip a switch which will divert it on to another track, where it will kill one person. Should you flip the switch?
The results: 77 percent said yes, 23 percent said no of 65,363 votes cast.
Again, the results are roughly three-quarters in favour of flicking the switch and one-quarter against. This is a surprising result. I'd have expected a greater consensus on diverting the trolley.
For those who wouldn't flip the switch, the consequences alone don't determine the morality of the act. Some moral rule (perhaps the duty not to kill innocent people) must have trumped any duty to maximise overall consequences (by saving as many people as possible).
How many people would need to be on that main track for you to change your mind? Is the moral rule absolute, or can it be overridden if the consequences reach a certain point - 10 people on the main track? Or 100 or 1,000?
3. THE FAT MAN AND THE TROLLEY CAR
Again, the runaway trolley car. You're standing on a bridge above and decide to jump on the track to block the trolley car. You will die, but five people on the track will be saved. But you are too light to stop it. Next to you is a fat man. He would certainly block the trolley, although he'd undoubtedly die. A small nudge and he'd fall right onto the track below. No one would ever know. Should you push him?
The results: 25 percent said yes, 75 percent said no of 52,178 votes cast.
The results are reversed in this case, as philosophers expect. The consequences are the same, but most opt to let the five people die. It appears that the end justify the means in the simple trolley case, but not in the modified version.
How can those who vote to flick the switch but not to push the fat man explain this apparent discrepancy? Is there a relevant moral rule present in this case but not the last? Is there a psychological dimension - you can see the fat man next to you and need to physically nudge him - that shifts the balance? Does this say something about the role of emotions in moral judgement?
4. THE CAVE EXPLORERS
A rock falls and blocks the exit of a cave you and five other tourists are exploring. You spot a hole elsewhere and decide to let Big Jack out first. A man of generous proportions, he gets stuck. There is no other way out.
The tide is rising and, unless you get out soon, everyone but Big Jack (whose head is sticking out of the cave) will inevitably drown. Searching through your backpack, you find a stick of dynamite. It will not move the rock, but will certainly blast Big Jack out of the hole. He pleads for his life; he does not want to die, but neither do you and your four companions. Should you blast him out?
The results: 75 percent said yes, 25 percent said no of 51,107 votes cast.
It's expected but nonetheless puzzling that the majority of you are not willing to push the fat man off the bridge, but are willing to blast him out of a hole to save five people. What are the relevant differences, if any, between the previous case and this one? Is it that you are trapped and self-preservation prevails?
Whatever our views, these experiments encourage us to examine our moral beliefs and intuitions and, perhaps, to uncover some inconsistencies in our thinking.
In light of these questions, it's unsurprising that philosophers are still grappling with these cases and their implications for morality and moral judgement. For those readers who are not deterred by the complexity, I recommend enrolling in an ethics course... or should you send the money to Oxfam?
- Does a person's right to life require us to make great personal sacrifices?
- If so, should we donate far more to humanitarian aid?
- Is there a moral difference between killing someone and letting that person die (this also has implications for the euthanasia debate)?
- When does the end justify the means?
- Are there actions we should never perform, whatever the consequences?
Daniel Sokol is a medical ethicist at Imperial College, London.