Justice Lecture 1: Trolley Problems

The first in what I hope will become a series of posts based on Michael Sandel's Justice lectures at Harvard (which can be obtained as podcasts from justiceonline.harvard.edu).

In this lecture, Sandel sets up several “Trolley problems,” philosophical thought experiments to probe our moral intuitions.

1. Split track. A train with no brakes is coming down the track. The track splits; on one side is tied one person, while 5 people are tied to the other side. On its current course, the train will kill the 5 people. You can throw a switch to redirect the train so that it kills only the 1 person. Do you throw the switch?

a. A: Yes, you throw the switch. Killing 1 person is better than killing 5. However the rule “Always kill as many lives as possible” should not be followed universally. For example, would you rather save two 90-year-old people both suffering from terminal cancer or one 30 year old single mother who has three children? You save the mother. Do you save two mentally-retarded people or the president of the United States? You save the president. So not all lives are equal; we value each life based on a number of things such as age, health, dependents, skills, etc. There is no simple formula, but I think we can agree that not all lives are equal.

2. The pusher. Now the only way to stop a train is to push a fat man (who is much fatter than you are) off a bridge so that he falls on the tracks, stopping the train and saving the 5 lives. Do you push him off?

a. A: No, you don’t push him. That’s what our moral intuition tells us, at least. It seems that it would be more unfair to push a man on the tracks than it would be in case 1 to throw a switch that ends up killing one man. Why does our moral intuition tell us this? Because our moral intuition is based on probable outcomes. We choose what is the right thing to do based on what will usually yield the optimum outcome (let’s say maximum utility), based on our limited knowledge in the real world. In the real world there are lots of ways to solve problems. If you want to stop a train, there are many things you can push into its path—a trash can, a hot dog stand, a car—besides a human being. Furthermore, there are other ways to save the 5 tied victims from a train besides pushing something in the way of it. Maybe there is some emergency braking system on the train or on the tracks. Maybe there is a switch to divert the train. In the real world, there are usually many options, and sacrificing an innocent person’s life hardly seems like the best one. The premise of the thought experiment is that the only way to save the 5 people’s lives is to push the one fat man, but in the real world we are rarely given such clarity of options. Maybe after the fact a careful analysis will reveal the only way to save these lives. But in the moment when we make a decision, we work with imperfect information and therefore have to follow rules that work (i.e., yield optimum outcomes) most of the time. We can explain the principle at work here as the Murder Rule: “Do not cause an innocent person to die unless you can be sure that the death of that one person will allow the saving of many more lives, and there are no other ways of saving those lives.” In this case, we are not sure that there is not another way to save the 5 lives. In the rare cases when it is very obvious in the moment that there are no other ways to save the 5 lives, then we are back to the split track situation of Case 1: Split Track.

3. The triage doctor. You’re a doctor who gets 6 patients. Five of them can be saved relatively quickly, but saving one of them will take so much time that you will not be able to get to any of the others. Who do you save?

a. Of course, you save the 5 people. This is analogous to Case 1: Split Track. You can be relatively confident (assuming, for example, that you’re the only doctor) that there is no other way to save the 5 lives than by operating on them first.

4. The transplant doctor. You’re a doctor with 6 patients. Five need different organ transplants. One is getting his wisdom teeth removed (general anesthesia) but is otherwise healthy. Do you sacrifice the healthy one, take out his organs, and then transplant them to the other 5 patients to save their lives? This is the only way to save their lives.

a. No, you can’t do that because that would violate the fairness of the healthy person. It violates the Murder Rule because in fact, in real life, you would never know that there are no other ways to save these 5 lives. Maybe more organs will come from new organ donors—which could arrive at any minute. Maybe there are other ways to save those 5 lives. One student in class had a brilliant solution: take 4 organs from whichever of the 5 dies first to save the other 4. In real life, these are the kinds of options that have to be considered.