This excerpt is from Michael J. Sandel, Justice: What's the Right Thing to Do?, pp. 21-30, by permission of the publisher.
The Runaway Trolley
Suppose you are the driver of a trolley car hurtling down the track at sixty miles an hour. Up ahead you see ve workers standing on the track, tools in hand. You try to stop, but you can’t. The brakes don’t work.You feel desperate, because you know that if you crash into these ve workers, they will all die. (Let’s assume you know that for sure.) Suddenly, you notice a side track, o to the right. There is a worker on that track, too, but only one.You realize that you can turn the trolley car onto the side track, killing the one worker, but sparing the ve. What should you do? Most people would say, “Turn! Tragic though it is to kill one innocent person, it’s even worse to kill ve.” Sacri cing one life in order to save ve does seem the right thing to do. Now consider another version of the trolley story. This time, you are not the driver but an onlooker, standing on a bridge overlooking the track. (This time, there is no side track.) Down the track comes a trolley, and at the end of the track are ve workers. Once again, the brakes don’t work. The trolley is about to crash into the ve workers. You feel helpless to avert this disaster—until you notice, standing next to you on the bridge, a very heavy man. You could push him o the
bridge, onto the track, into the path of the oncoming trolley. He would die, but the ve workers would be saved. (You consider jumping onto the track yourself, but realize you are too small to stop the trolley.) Would pushing the heavy man onto the track be the right thing to do? Most people would say, “Of course not. It would be terribly wrong to push the man onto the track.” Pushing someone o a bridge to a certain death does seem an awful thing to do, even if it saves ve innocent lives. But this raises a moral puzzle:Why does the principle that seems right in the rst case—sacri ce one life to save ve—seem wrong in the second? If, as our reaction to the rst case suggests, numbers count—if it is better to save ve lives than one—then why shouldn’t we apply this principle in the second case, and push? It does seem cruel to push a man to his death, even for a good cause. But is it any less cruel to kill a man by crashing into him with a trolley car? Perhaps the reason it is wrong to push is that doing so uses the man on the bridge against his will. He didn’t choose to be involved, after all. He was just standing there. But the same could be said of the person working on the side track. He didn’t choose to be involved, either. He was just doing his job, not volunteering to sacri ce his life in the event of a runaway trolley. It might be argued that railway workers willingly incur a risk that bystanders do not. But let’s assume that being willing to die in an emergency to save other people’s lives is not part of the job description, and that the worker has no more consented to give his life than the bystander on the bridge has consented to give his. Maybe the moral di erence lies not in the e ect on the victims— both wind up dead—but in the intention of the person making the decision. As the driver of the trolley, you might defend your choice to divert the trolley by pointing out that you didn’t intend the death of the worker on the side track, foreseeable though it was; your purpose would still have been achieved if, by a great stroke of luck, the ve workers were spared and the sixth also managed to survive.
DOING THE RIGHT THING
But the same is true in the pushing case. The death of the man you push o the bridge is not essential to your purpose. All he needs to do is block the trolley; if he can do so and somehow survive, you would be delighted. Or perhaps, on re ection, the two cases should be governed by the same principle. Both involve a deliberate choice to take the life of one innocent person...