Would You Kill One Person To Save Five?

The situation is the same as before: a runaway tram threatens to kill five people. A very heavy man is sitting on a wall on a bridge spanning the track. You can stop the train by pushing him off the bridge onto the track in front of the train. He will die, but the five will be saved. (You can’t opt to jump in front of the tram yourself since you aren’t big enough to stop it.)

From a simple utilitarian point of view, the dilemma is the same — do you sacrifice one life to save five? — and the answer is the same: yes. Interestingly, however, many people who would pull the lever in the first scenario would not push the man in this second scenario. This raises two questions:

The Moral Question: If Pulling the Lever Is Right, Why Would Pushing the Man Be Wrong?

One argument for treating the cases differently is to say that the doctrine of double effect no longer applies if one pushes the man off the bridge. His death is no longer an unfortunate side-effect of your decision to divert the tram; his death is the very means by which the tram is stopped. So you can hardly say in this case that when you pushed him off the bridge you weren’t intending to cause his death.

A closely related argument is based on a moral principle made famous by the great German philosopher Immanuel Kant (1724-1804). According to Kant, we should always treat people as ends in themselves, never merely as a means to our own ends. This is commonly known, reasonably enough, as the “ends principle.” It is fairly obvious that if you push the man off the bridge to stop the tram, you are using him purely as a means. To treat him as the end would be to respect the fact that he is a free, rational being, to explain the situation to him, and suggest that he sacrifice himself to save the lives of those tied to the track. Of course, there is no guarantee that he would be persuaded. And before the discussion had got very far the tram would have probably already passed under the bridge!

The Psychological Question: Why Will People Pull the Lever but Not Push the Man?

Psychologists are concerned not with establishing what is right or wrong but with understanding why people are so much more reluctant to push a man to his death than to cause his death by pulling a lever. The Yale psychologist Paul Bloom suggests that the reason lies in the fact that our causing the man’s death by actually touching him arouses in us a much stronger emotional response. In every culture, there is some sort of taboo against murder. An unwillingness to kill an innocent person with our own hands is deeply ingrained in most people. This conclusion seems to be supported by people’s response to another variation on the basic dilemma.

Here the situation is the same as before, but instead of sitting on a wall the fat man is standing on a trapdoor built into the bridge. Once again you can now stop the train and save five lives by simply pulling a lever. But in this case, pulling the lever will not divert the train. Instead, it will open the trapdoor, causing the man to fall through it and onto the track in front of the train.

Generally speaking, people are not as ready to pull this lever as they are to pull the lever that diverts the train. But significantly more people are willing to stop the train in this way than are prepared to push the man off the bridge.

Suppose now that the man on the bridge is the very same man who has tied the five innocent people to the track. Would you be willing to push this person to his death to save the five? A majority say they would, and this course of action seems fairly easy to justify. Given that he is willfully trying to cause innocent people to die, his own death strikes many people as thoroughly deserved. The situation is more complicated, though, if the man is simply someone who has done other bad actions. Suppose in the past he has committed murder or rape and that he hasn’t paid any penalty for these crimes. Does that justify violating Kant’s ends principle and using him as a mere means?

Here is one last variation to consider. Go back to the original scenario–you can pull a lever to divert the train so that five lives are saved and one person is killed–but this time the one person who will be killed is your mother or your brother. What would you do in this case? And what would be the right thing to do?

A strict utilitarian may have to bite the bullet here and be willing to cause the death of their nearest and dearest. After all, one of the basic principles of utilitarianism is that everyone’s happiness counts equally. As Jeremy Bentham, one of the founders of modern utilitarianism put it: Everyone counts for one; no-one for more than one. So sorry mom!

But this is most definitely not what most people would do. The majority may lament the deaths of the five innocents, but they cannot bring themselves to bring about the death of a loved one in order to save the lives of strangers. That is most understandable from a psychological point of view. Humans are primed both in the course of evolution and through their upbringing to care most for those around them.  But is it morally legitimate to show a preference for one’s own family?

This is where many people feel that strict utilitarianism is unreasonable and unrealistic. Not only will we tend to naturally favor our own family over strangers, but many think that we ought to. For loyalty is a virtue, and loyalty to one’s family is about as basic a form of loyalty as there is. So in many people’s eyes, to sacrifice family for strangers goes against both our natural instincts and our most fundamental moralintuitions.