The so-called trolley problem, which single handedly appears to have kept a generation of moral philosophers in a job, is now well known. The problem, simply put, is why the intuitions of many as to the correct course of action differ between the following two cases which I have paraphrased from Judith Jarvis Thomson’s 1985 paper, “The Trolley Problem”:
Bystander at the switch
An out of control train is headed down a track and is on course to kill five people. You are an innocent bystander standing at a switching point. If you flick the switch, the train is diverted to a spur track. The five people will be saved but unfortunately, there is one person tied to the spur track and he will die. Should you flick the switch?
An out of control train is headed down a track and is on course to kill five people. You are an innocent bystander standing on a footbridge over the track. Next to you, standing precariously on the edge of the footbridge, is a fat man. If you give the fat man a little push he will fall onto the track and his weight will stop the train and hence prevent the five from being killed. Unfortunately, the fat man dies. An act of self-sacrifice such as jumping off the bridge yourself would not work as your own weight is not sufficient to stop the train. Should you push the fat man?
Much on the literature on this problem is to try and explain and justify the authors’ views, in line with the intuition of many, why it is acceptable to kill one to save five in Bystander at the switch but not acceptable to kill one to save the five in Fat Man.
However, Judith Jarvis Thomson had a paper published in 2008 entitled “Turning the Trolley” where she admitted that she had changed her view. She now thought it wrong to flick the switch in Bystander at the switch. She constructed a new thought experiment that I paraphrase below:
Bystander’s Three Options
An out of control train is headed down a track and is due to kill five people. You are a bystander standing on a left hand spur. There is also a workman on right handed spur track. Your three options are (i) do nothing in which case five people die, (ii) flick the switch to the right in which case the only person who dies is the workman on the spur, or (iii) flick the switch to the left killing yourself and no one else.
Thomson reasons: “I hope you will agree that choosing (ii) would be unacceptable on the bystander’s part. If he can throw the switch to the left and turn the trolley onto himself, how dare he throw the switch to the right and turn the trolley onto the one workman?” She goes on to explain that self-sacrifice is not required: “[A man] may let five die if the only permissible means he has of saving them is killing himself.”
It is this version of one of the many trolley problem thought experiments that is taken up by Howard Nye in his paper: “On the Equivalence of Trolleys and Transplants: The Lack of Intrinsic Difference between ‘Collateral Damage’ and Intended Harm,” just published in the December 2014 issue of Utilitas. (Sadly, the link requires a subscription. It is not free to access.) Nye explains that he was convinced that Thomson’s Bystander’s Three Options was equivalent to his own thought experiment below:
Bazooka Holder’s Three Options.
You, Bugsy and the five are tied to three parallel trolley tracks, and empty trolleys are heading down each track. You have a bazooka with only two rounds, giving you three options: (1) blow up the trolleys heading towards the five and Bugsy, in which case only you will die; (2) blow up the trolleys heading towards the five and you, in which case only Bugsy will die; or (3) blow up the trolleys heading towards Bugsy and you, in which case only the five will die.
The problem is that these examples are not similar enough. There is a key moral difference and it has to do with the acts and omissions doctrine. This should not be elided without reasoning. These differences can be noted:
- Doing nothing in Bystander’s Three Options mean five people die, whereas doing nothing in Bazooka Holder’s Three Options means seven people die. This option of doing nothing is not noted by Nye as one of the bazooka holder’s three options. Doing nothing is noted as an option by Thomson in Bystander’s Three Options.
- Five people dying and no one else dying in Bystander’s Three Options results from doing nothing. The five people dying and no one else dying in Bazooka Holder’s Three Options results from the bazooka holder doing something: choosing to save himself and save Bugsy.
- Only one person (not the bystander) dying in Bystander’s Three Options results from doing something that kills the man on the spur. Only one person (not the bazooka holder) dying in Bazooka Holder’s Three Options results from the bazooka holder doing something to save the five and save himself. The Bazooka holder lets Bugsy die, he does not kill him.
- Only the bystander dying in Bystander’s Three Options results from the bystander committing suicide. Only the bazooka holder dying in Bazooka Holder’s Three Options arises from the bazooka holder choosing to saving six other people and letting himself die.
These differences are important. It is a well established relevant moral fact that there is a difference between killing a man and letting him die. It is crucial in many areas, notably the debate on euthanasia. It is also important in law: the difference between killing a man (drowning him in a river) and not saving his life (a bystander with no special duty of care not throwing a lifebelt to a drowning man) is the difference in countries such as England and America between going to prison for many years for murder or manslaughter and getting off scot-free.
Recall that Thomson argues that a man “may let five die if the only permissible means he has of saving them is killing himself.” In response, Nye states:
It is indeed plausible that it is wrong to force a cost on someone if she isn’t morally obligated to assume it. There are, however, cases in which we do seem permitted to do things that result in someone’s bearing a cost that she would not be obligated to assume herself. We seem permitted, in cases like Bazooka Holder’s Three Options, to save ourselves rather than Bugsy even though Bugsy would not be required to save us rather than himself.
This is problematic because Nye has not made a comparable argument. In Bazooka Holder’s Three Options, if the Bazooka holder chooses to save the five and himself it is not what the Bazooka holder has done that results in Bugsy “bearing a cost” (dying). Bugsy dies because without any action on the Bazooka holder’s behalf he would die anyway. Bugsy has no positive right that the Bazooka holder should save him.
While the five in Bazooka Holder’s Three Options also have no positive right to be saved, let us assume out of the goodness of your heart, you, the Bazooka Holder, used one of your bazooka rounds to save the five. If so, we are now left with the following problem.
Bazooka Holder’s Three Options (Revised)
You and Bugsy are tied to parallel trolley tracks, and empty trolleys are heading down each track. You have a bazooka with one round. You have three options: (i) do nothing in which case you will both die, (ii) blow up the trolley heading towards yourself, saving yourself and letting Bugsy die, (iii) blow up the trolley heading towards Bugsy saving Bugsy and letting yourself die.
This revised problem is morally equivalent to the following:
Jug of Water
You and Bugsy are journeying through the desert and you have a single jug of water. You have three options (i) Share the water with Bugsy in which case you will both die as there is an insufficient amount to keep you both alive, (ii) give the jug of water to Bugsy such that he survives and you die, (iii) drink the water yourself such that you survive and Bugsy dies.
Some readers may be familiar with this version. It predates Judith Jarvis Thomson’s trolley problem by nearly two millennia. It arises in a dispute between Rabbi Akiva and Ben Petura on Leviticus 25:36. The answer to Jug of Water, according to Rabbi Akiva and Jewish law, is that you are not required to give up your own life so another might live. “Your life becomes before the life of your fellow man.” This is contrasted with a different Talmudic problem: Can a man threatened with death kill another man to save his own life? The answer, according to the Jewish tradition, is no: “who shall say your blood is redder than his? Perhaps his blood is redder than yours.”
The point of me providing these last examples is not to promote Jewish ethical values, but to demonstrate that even in ancient times it was recognised that there is a moral difference between killing and letting die. This difference explains a crucial differential between Bystander’s Three Options and Bazooka Holder’s Three Options.