Alice has just fed a poison to Bob. Bob hasn’t died yet. He is standing, by coincidence, on the edge of a cliff, and soon will die of the poison, unless he gets an antidote. Carl is there and has a syringe full of the antidote. Carl injects Bob with the antidote, but this startles Bob and Bob falls off the cliff to his death.
Question 1: Did Alice murder Bob?
Answer: I think not. Here’s an argument. Bob dies as a side-effect of injection with the antidote. But it could just as well have been Carl who slipped and fell while injecting Bob instead of Bob falling. And surely then we shouldn’t say that Alice murdered Carl—though she did wrongfully cause his death.
Question 2: Suppose that Carl was Alice’s friend and foresaw that Bob would fall off the cliff to his death if injected with the antidote, but reasoned: “I am saving Alice from being a murderer.” Could one legitimately make this double-effect analysis? “Carl is intending that Alice not be a murderer. His means to that is giving Bob an antidote to the poison. A foreseen side-effect of Carl’s action is Bob’s death, but this side-effect is not intended either as an end or as a means. And given that Bob would have died anyway, the side-effect is not disproportionate to the good of saving Alice from being a murderer.”
Answer: I think the proportionality condition is not met. Sure, Carl makes Alice not be a murderer. But Alice is still an attempted murderer—which is just as culpable as being an actual murderer—and her malfeasance still causes Bob’s death, so she still has that death on her conscience. Granted, she isn’t a murderer any more (if I am right about Question 1), but the bad of Carl’s accidentally killing Bob seems disproportionate to the relatively minor good achieved here.
It’s interesting when it is the proportionality condition in double effect that ends up being crucial.