Ethics · Philippa Foot, 1967; developed by Judith Jarvis Thomson
The trolley problem
Is it right to harm one person to save five?
The most famous dilemma in ethics. Not because the answer is obvious, but because almost everyone’s answers contradict each other.
1The puzzle
A runaway trolley is heading down the track towards five workers who can’t get out of the way. You’re standing by a lever. Pull it, and the trolley switches to a side track, where one worker is standing. You have a few seconds. Decide.
The trolley is coming. What do you do?
2Take a stand
A runaway trolley will kill five people. You can pull a lever to send it onto a side track, where it will kill one. Should you pull it?
There’s no right answer here. Pick the one closest to what you actually think. We’ll test it next.
3The push-back
A few situations designed to test your answer. After each one, you can hold your ground or shift. Watch where you end up.
4The map of answers
You’re not the first to wrestle with this. Tap a thinker to see their answer and the strongest case for it. Open at least two.
5Turn it on yourself
You will probably never stand by a lever. But you trade off harms all the time: who bears a cost so others benefit, when a rule should bend, and when it mustn’t.
Your answers stay in this browser. Nobody else sees them.
6Your question card
The trolley problem
Is it right to harm one person to save five?
When doing harm saves more lives, does the outcome settle it, or are some acts off-limits whatever the numbers?
The main answers
Jeremy Bentham: The right act is whichever produces the greatest happiness for the greatest number.
Peter Singer: Our gut reactions in cases like the footbridge are evolutionary leftovers, not moral insight.
Aristotle: Ask what a good, wise person would do, not which rule to follow.
Philippa Foot: There’s a real difference between doing harm and allowing harm, and between intending it and foreseeing it.
Judith Jarvis Thomson: You may not use a person as a mere means, even to save more lives.
Immanuel Kant: Never treat a person merely as a means to an end.
Where you stand
Your note
Notice this week
Notice the next time a decision at work or in the news sacrifices a few for the many. Ask: is this a lever or a push?