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June 15, 2008



"Now I know people say that "people will say the same thing about the loop as in the original switch case" but I have never actually met anyone who will say that."

I will say that. The LOOP case is morally equivalent to the original switch case. I'm extremely confident of that. I'm less certain whether the PUSH case is the same or different from the other two. I could see that one going either way. But I'd be baffled by anyone who didn't classify LOOP and DIVERT together.

On the artificiality of your earlier distinction, I don't see why using a human body as a prop should make an act any less yours than using an inanimate prop. (You wouldn't say, for example, that it was really *the switch*, rather than the person who pulled it, which saved the five lives in the original case!) If the fat man's agency was involved, maybe that would be a relevant difference. But I just think it misdescribes the situation to deny that the person who pushes the fat man in front of the trolley thereby saves five lives. (A "parlor trick", you might say!)

Terry Tomkow

It is certainly possible to think that it is impermissible for the bystander to act in any of the three cases. (That is, in fact, my own view.)

And it is certainly possible to take the Heroic Utilitarian line and insist that you may push n men under the trolley provided that n + 1 are saved.

But I don't know how one says PUSH is bad but LOOP is okay. I've never heard anyone argue that case (though I've heard plenty of people say thats what "other people" think).

Maybe you will be the first. Let me know when you decide where you come down on PUSH and why.

As for why it makes a difference who does what... well, like I said. Stay tuned.


I don't see a moral difference between LOOP and DIVERT as long as the person who pulls the switch knows in each case that their action will result in someone's death. It seems to me that the reason people are claiming a difference between the two is due to the fact that in the LOOP case, without the Fat Man's presence, the train would still go back to the main line killing the five people in danger there. Throwing the switch sends the train onto the alternate loop with the fat man on it; before the train can get back onto the main line where the five people lay waiting it is stopped by the fat man tied to the tracks. In the original DIVERT case, the train is sent onto an entirely different track, one where it will avoid hitting the five people whether it is stopped or allowed to continue running. It just happens that there is a person on the track that will, by happenstance, be struck and killed when the train is diverted. As opposed to the LOOP case where the other person's presence is the actual reason why the five are saved. Again, from my view, as long as the switch puller knows that her actions will result in the death of one instead of five, then the acts are morally equivalent.


All three are morally equivalent. I would refuse to participate and instead kill whomever put me in that position in the first place. He/she is the one morally responsible for any deaths.

Chris Anderson

First let me start by saying I don't agree with your interpretation of "you prevent" in i). You say that:

It is permissible for you to do something, α, that kills one person if:
i) by doing α you prevent the death of five people.
ii) if you refrain from doing α the five people will die.

You then go on to say that in the fat man cases what makes it unacceptable is that the actor does not fulfill the conditions established by i). In particular that the agent is not the one that physically stops the train. I contend-like others-that this is an artificial distinction. For example, imagine that instead of the fat man you push a large rock that stops the train. That would still seem to satisfy i). Therefore, you have to either show me why the large rock counterexample does not satisfies i) or say why the analogy is not helpful.

I'd like to end by trying to challenge your intuitions. You stated (I believe) that you have an obligation in the trolley problem not to act. If that is the case, do you feel that there is a difference in the diversion problem between not acting and acting twice? I'll clarify, imagine that you divert the train towards the single person but afterwards think better of it and divert the train back towards the five. Is there a moral difference between this and not acting?


The whole scenario strikes me like straight out of one of those cheesy slasher films for adolescents like Saw or Jack Bauer in 24. When I imagine this situation I feel the presence of a man behind me with a gun who has forced me into this horrible mess. Is that really how we make moral choices? I don't think so.



There may be a significant difference between the way the law would treat PUSH and LOOP, the latter being treated as a much worse offense. I don’t have Thomson’s original papers in front of me, so I must ask you to clarify some of the details of LOOP. How does the fat man get tied to the rails of the siding? Are we to imagine that the man at the switch somehow has time to go off and seize and tie fat man to the track? That right there is a serious criminal act, and in view of the homicide that follows, would likely be seen as clear pre-meditation. If, alternatively, we are to imagine that some gang of hooligans has already tied fat man to the track, and the man at switch merely takes advantage of fat man’s predicament, there is a clear absence of pre-meditation. You mention that fat man’s family may wish to bring a wrongful death suit against the man at the switch. Indeed, but that is likely the least of his problems. If I were the prosecutor in this kind of case, my deliberation would be whether to pursue a murder charge against the man at the switch, or let him plead to manslaughter.

The law wisely does not allow us to intentionally kill innocent bystanders in order to try to rescue people in grave peril. There is no defense at law for the homicide the man at the switch causes. Rescue professionals and LE personnel are in fact repeated cautioned and drilled in their civil & criminal liability if they intentionally cause the death of innocent bystanders. A further argument that the man at switch is doing something criminally wrong would arise from this complication. Suppose some of fat man’s relatives are present at the scene and warn the man standing at the switch not to divert the trolley. When he ignores their warning and grabs the switch, the relatives of fat man shoot the man at the switch dead. That homicide, I believe, would be considered fully justified under most state criminal codes because the man at the switch is about to commit a homicide.

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