Tomkow.com

Trolley Problems

You've heard this one before:

TROLLEY
A runaway trolley is coming down the track. It is headed towards five people who cannot get out of its way. A Passerby realizes that he can save the five by throwing a switch and diverting the trolley down a siding, but he also realizes that if he does so, the trolley will kill a Lone Man standing on the siding.

Should you divert the trolley? Lots of folks say, "Yes!" Whether or not they are right is an interesting problem but it is not what philosophers call "The Trolley Problem". That problem involves a different case:

FAT MAN
A runaway trolley is coming down the track. It is headed towards five people who cannot get out of its way. A passerby realizes that if he pushes a nearby fat man onto the tracks his bulk will stop the trolley before it hits the five, though the fat man himself will be killed.

Most people, including those who think it is okay to turn in TROLLEY, think that it is not okay to push the FAT MAN. "The Trolley Problem" is how to reconcile these two answers. In both cases it seems you can do something that will save five people but only by killing one. How can anyone think it okay to turn in TROLLEY but wrong to push the FAT MAN? What difference is there between the two stories that can possibly make a moral difference?

In the almost forty years since Judith Jarvis Thomson first posed the problem in this form there have many attempts to solve it but none is generally accepted as successful. Indeed a general consensus seems to have developed that the "folk intuitions" (as philosophers call them) about the difference between these cases are simply irrational.

Thus a Utilitarian like Peter Unger can argue that, since there is no difference, it must be morally okay to go around doing things like pushing fat men under trolleys so long as it promotes the general happiness.

Meanwhile Judith Jarvis Thomson concludes that, since there is no difference between the cases, it must be wrong to turn in TROLLEY and so FAT MAN represents a reductio ad absurdum of Utilitarianism.

Both sides explain away "folk intuitions" that the cases are somehow different as a psychological aberration. Folks feel better about killing other folks in TROLLEY-- this theory goes-- because they are more comfortable with throwing a remote switch in TROLLEY than they are with the up close shoving that FAT MAN requires. There are even psychological "experiments" and (God help us) neural imaging studies that are supposed to explain (away) these folksy confusions.

In a conflict between folk intuitions and philosophical theory I'll bet on the folk every time. In this post, I'm not going to take a position on whether or not it is permissible to turn in TROLLEY or push the FAT MAN. My goal instead is to show that, as described, there are subtle but important differences between the FAT MAN and TROLLEY cases; differences that can make a moral difference in other circumstances, but differences that have, hitherto, gone overlooked by philosophers.

We begin with some different thought experiments.

SACRIFICING OTHERS
A runaway trolley is coming down the track. It is headed towards a Lone Man on the tracks who cannot get out of the way. However that man is standing by a switch which, if thrown, will divert the trolley down a siding. In that case the man will be safe but he can also see that, in that case, five people standing on the siding will be killed.

Is it morally permissible for the man to throw the switch? If it is permissible, what of this:

SHIELDING ONESELF
A man sees that someone is about to shoot him. To protect himself, he grabs an innocent bystander and uses her as a shield.

Now there is a line of thought that says that when one's life is in danger, anything goes. The philosopher Hobbes seems to have held something like this position. But this seems to me to throw morality out the window when it may be most required. It seems to me that SHIELDING ONESELF and SACRIFICING OTHERS are clearly impermissible and in what follows I'm going to assume you agree with me.

Now consider.

SELF DEFENSE
A runaway trolley is coming down the track. Luckily there is no one in its path. A passerby, Burns, sees this but he also notices that Homer, someone he hates, is standing on a siding. Burns realizes that if he throws a nearby switch, the trolley will be diverted down the siding killing Homer. Homer can see all this too and when he sees Burns moving towards the switch he correctly guesses his intent. Homer cannot get out of the way but he is not defenseless: he has a gun. He draws it and shouts "Stop or I'll shoot!". But Burns ignores him and keeps moving the switch.

Assuming all these facts, I expect you to agree with me that it would be morally permissible for Homer to pull the trigger. It seems an ordinary case of self-defense albeit against an unusual attack.

Now for the interesting case:

Thrown for a loop

[I don't like blog software's treatment of comments. Reading through a comment thread is like reading a series of footnotes to footnotes, not a conversation.  So my practice will be to try to include good comments in the main body of the blog where they get the attention they deserve.]

Responding to my proposed solution to The Trolley Problem, Richard Chappell writes.

I dunno, the distinction between (directly) preventing the deaths vs. causing them to be prevented (by someone else) strikes me as a bit artificial. But in any case, I don't think it tracks the standard Trolley intuitions. Consider the loop case: (8) You can pull a switch to divert the trolley onto a loop which connects back onto the main track where 5 victims await. Normally this wouldn't help, but fortunately there's a fat man tied to the rails in the loop section, who will bring the train to a halt if it hits him. Should you pull the switch? Presumably anyone who would divert the trolley in the original case would also do so in the loop case. But you would say it's the fat man, rather than the switch-puller, who directly prevents the 5 deaths in this case. So directly preventing the deaths cannot be the grounds for pulling the switch. An alternative candidate explanation would be to appeal to whether Jones brings about the one death (saving the five) by acting on the victim (e.g. pushing him), or by indirect means (pulling a switch). Perhaps our intuitions reflect the principle that only the latter (i.e. indirectly causing death) is permissible.

Thanks for your comment!

Let’s spell out the relevant cases:

DIVERT:  A runaway trolley is coming down the tracks.  It will hit five people if it is not diverted down a different track, but there is one person who will be killed if the trolley takes that route. Seeing this, a bystander throws a switch which diverts the trolley.  The one is killed; the five survive; the trolley continues on its way.

PUSH:  A runaway trolley is coming down the tracks.  It will hit five people if it isn't stopped.  A bystander pushes a fat man onto the tracks.  As the bystander intended, the trolley hits the fat man, killing him but stopping the trolley before it hits the five.

LOOP: A runaway trolley is coming down the tracks.  It will hit five people if it isn't stopped.  A bystander throws a switch which diverts a trolley down a siding.  The siding loops back to the main line and is still headed for the five, but there is a fat man on the siding track who is struck by the trolley, killing him, but stopping the trolley before it hits the five. All as the bystander intended.

Thomson’s LOOP case is a kind of parlor trick that flummoxes everyone when we first encounter it but I think its significance is generally misunderstood...

A Solution to the Trolley Problem

In the trolley problem some people think it is permissible for a bystander to turn the trolley onto the one to save the five. But many of those same people do not think it permissible to push a fat man onto the track to stop the trolley from running over the five.

The Trolley Problem is not to say whether this opinion is correct, but to explain what non-moral difference between these cases could reasonably lead people to these different verdicts in these two cases.  This is a problem even for someone who does not think it permissible to turn from the one onto the five.

In what we may call the standard trolley case a bystander has the choice of throwing a switch which will divert the trolley or not throwing the switch. I take it that people who believe that it is permissible to throw the switch in the standard case believe the following.

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.

The Problem is why this principle does not also permit pushing the fat man in front of the trolley. 

To see why consider the following cases.

Trolley Poem

The Trolley Problem

Most people, they say, will turn from the five
onto the one.
I'm sure they're right.

Most people got no idea about railroading.
Don't know how to start one, don't know how to stop.
But they'll turn on you.
Bystanders. Most People.
Standing by to run you down.

Most people will raise your taxes.
Most people will take your house for a ball park.
Most people will send your boy to die in a foreign war just because
they think they might see something,
way down the road,
they'd rather not run into.

Most people stick to the main line.
Most people don't trust the one.
What's he doing out there,
on his own track,
outlying?

So they'll grind that one under
and won't think twice about it.

Most people can do the math.