The DDE is DDEad
Two negative effects of accepting the doctrine of double effect
Let me preface this by saying that I am going to wade into a dispute that exactly googolplex things have been written by philosophers about. So bear in mind the traditional boring caveat that I am not the leading authority on this, I have read .000000000000000000001% of the total things that have been written about it, and one should do more research to form an opinion rather than just reading what I say. Also blah blah, more research needs to be done, etc. Okay, with that throat clearing out of the way, I think the doctrine of double effect has a problem.
For those who don’t know, the doctrine of double effect is designed to explain something that philosophers spend a concerningly large amount of time thinking about—namely, when it’s okay to kill people. More specifically, when it’s okay to cause someone’s death in the pursuit of a greater good.
The doctrine of double effect says that you can cause someone’s death if that’s a side effect of achieving a greater good but you can’t intend to cause their death. So it’s permissible to flip the switch in the trolley problem to redirect the train from 5 to 1, but it’s not permissible to push the fat guy off the bridge to stop the train because in the first case, it’s an unfortunate side effect, but in the second case you intend to kill them.
A natural response is the following: the person who pushes the fat guy off the bridge doesn’t intend for the people to die, they intend to save lives. But the DDE defender replies that they do intend for them to die in that their action wouldn’t work unless they died. If the person rolled out of the way and didn’t get run over, the person who pushed them off the bridge would be sad while the person who flipped the switch would be happy.
But even this isn’t right! If the person rolled out of the way, in a way that stopped the train, the person who pushed them would be happy. In contrast, if the person in the switch case redirected the train back to the five somehow, the switch flipper would be distraught. So in both cases, there are a range of possible scenarios in which the actor hopes for the probable victim to die and a range of cases in which they don’t.
The reply given by DDE defenders (ddefenders) is that in the bridge case, cases where the person survives to the satisfaction of the pusher are the exception, while in the switch case they are the rule. If all one knows is that the extra person survived, they’d be relieved in the switch case but disappointed in the bridge case. Thus, while in both cases there are some scenarios where the person is disappointed and others where they are overjoyed from the survival of the person, what matters is the relative likelihood of each.
But this doesn’t work either! There are two broad categories of cases that this account fails to explain—namely, cases where in nearly all survival cases one is happy, but the act still seems wrong, and cases where in nearly all survival cases one is unhappy, but the act seems right. For the first category of cases, consider the following:
Suppose that you push a very very fat man off a bridge to stop a train. This guy is so fat that you think there’s some chance that he’ll stop the train without being harmed at all. In contrast, he’s clearly not going anywhere—so you know that if he survives, it will be good news; it will be because he successfully stopped the train. You’re a utilitarian after all—you want him to survive as long as it doesn’t cost any other lives. Nonetheless, it seems wrong to push him.
Suppose you bomb a bridge in a war. You do this with the aim of frightening an enemy by causing the bridgegoers to scream. Suppose that you know that if the bridgegoers survive, they will scream. This seems impermissible on commonsense morality, but in this scenario, you hope the people survive—if they end up surviving, there’s a guarantee that you’ll get what you want.
The second category of cases is just as decisive:
You bomb a bridge in a war with the intention to stop supply lines. However, the bridge is populated by very conscious and intelligent turtles that move very slowly. It seems permissible to do this if it would save many lives (crucially, it doesn’t seem to make any difference whether the turtles were fast and able to get away). But on this view, only the first would be permissible.
Suppose that whenever people escape from train tracks, they explode and kill 10 people. This would mean that you would hope that the person in the switch case doesn’t survive. Still, it seems permissible to flip the switch.
I’m not really sure what the defender of the doctrine of double effect can say here, so let me know. Is there any way out?
Check out Quinn's 'Actions, Intentions, and Consequences: The Doctrine of Double Effect' https://philpapers.org/rec/QUIAIA-2
He clarifies the view in terms of a distinction between 'harmful direct agency' and 'harmful indirect agency'. The former is that "... in which harm comes to some victims, at least in part, from the agent’s deliberately involving them in something in order to further his purpose precisely by way of their being so involved." And it's this kind of harmful agency that the DDE counts as especially weighty.
Alex Pruss notes that lots of double-effect advocates in the Catholic tradition (e.g. Anscombe, Koons, and so on) think that "if something is known to inevitably and directly follow from something that one intends, then one intends that, too." This rules out disingenuous cases (e.g. bombing Hiroshima and saying your intention to was to end the war, not kill civilians). That could be useful for some of your cases (though it also raises questions about switch-flipping in the trolley case; Anscombe herself thought switch-flipping was wrong).