I do not find it clear why there should be an exemption for, and only for, making a burden which is descending onto five descend, instead, onto one. That there is seems to me very plausible, however. On the one hand, the agent [62]who acts under this exemption makes be a threat to one something that is already a threat to more, and thus something that will do harm whatever he does; on the other hand, the exemption seems to allow those acts which intuition tells us are clearly permissible, and to rule out those acts which intuition tells us are clearly impermissible. [1409]
More precisely, it is not morally required of us that we let a burden descend out of the blue onto five when we can make it instead descend onto one if we can make it descend onto the one by means which do not themselves constitute infringements of rights of the one.
Consider a case – which I shall call Fat Man – in which you are standing on a footbridge over the trolley track. You can see a trolley hurtling down the track, out of control. You turn around to see where the trolley is headed, and there are five workmen on the track where it exits from under the footbridge. What to do? Being an expert on trolleys, you know of one certain way to stop an out-of-control trolley: Drop a really heavy weight in its path. But where to find one? It just so happens that standing next to you on the footbridge is a fat man, a really fat man. He is leaning over the railing, watching the trolley; all you have to do is to give him a little shove, and over the railing he will go, [64]onto the track in the path of the trolley. Would it be permissible for you to do this? Everybody to whom I have put this case says it would not be. But why?
Suppose the agent proceeds. He shoves the fat man, thereby toppling him off the footbridge into the path of the trolley, thereby causing him to be hit by the trolley, thereby killing him – but saving the five on the straight track. Then it is true of this agent, as it is true of the agent in Bystander at the Switch, that he saves his five by making something which threatens them instead threaten one.
But this agent does so by means which themselves constitute an infringement of a right of the one’s. For shoving a person is infringing a right of his. So also is toppling a person off a footbridge.
I should stress that doing these things is infringing a person’s rights even if doing them does not cause his death – even if doing them causes him no harm at all. As I shall put it, shoving a person, toppling a person off a footbridge, are themselves infringements of rights of his. A theory of rights ought to give an account of what makes it be the case that doing either of these things is itself an infringement of a right of his. But I think we may take it to be a datum that it is, the job which confronts the theorist of rights being, not to establish that it is, but rather to explain why it is.
Consider by contrast the agent in Bystander at the Switch. He too, if he proceeds, saves five by making something that [66]threatens them instead threaten one. But the means he takes to make that be the case are these: Turn the trolley onto the right-hand track. And turning the trolley onto the right-hand track is not itself an infringement of a right of anybody’s. The agent would do the one no wrong at all if he turned the trolley onto the right-hand track, and by some miracle the trolley did not hit him. [1410]
We might of course have imagined it not necessary to shove the fat man. We might have imagined that all you need do to get the trolley to threaten him instead of the five is to wobble the handrail, for the handrail is low, and he is leaning on it, and wobbling it will cause him to fall over and off. Wobbling the handrail would be impermissible, I should think – no less so than shoving. But then there is room for an objection to the idea that the contrast I point to will help explain the moral differences among these cases. For it might be said that if you wobble the handrail, thereby getting the trolley to threaten the one instead of the five, then the means you take to get this to be the case are just these: Wobble the handrail. But doing that is not itself an infringement of a right of anybody’s. You would do the fat man no wrong at all if you wobbled the handrail and no harm came to him in consequence of your doing so. In this respect, then, your situation seems to be exactly like that of [68]the agent in Bystander at the Switch. Just as the means he would be taking to make the trolley threaten one instead of five would not constitute an infringement of a right, so also would the means you would be taking to make the trolley threaten one instead of five not constitute an infringement of a right.
What I had in mind, however, is a rather tighter notion of “means” than shows itself in this objection. By hypothesis, wobbling the handrail will cause the fat man to topple onto the track in the path of the trolley, and thus will cause the trolley to threaten him instead of the five. But the trolley will not threaten him instead of the five unless wobbling the handrail does cause him to topple. Getting the trolley to threaten the fat man instead of the five requires getting him into its path. You get the trolley to threaten him instead of them by wobbling the handrail only if, and only because, by wobbling the handrail you topple him into the path of the trolley.
What I had in mind, then, is a notion of “means” which comes out as follows. Suppose you get a trolley to threaten one instead of five by wobbling a handrail. The means you take to get the trolley to threaten the one instead of the five include wobbling the handrail, and all those further things that you have to succeed in doing by wobbling the handrail if the trolley is to threaten the one instead of the five.
[70]So the means by which the agent in Fat Man gets the trolley to threaten one instead of five include toppling the fat man off the footbridge; and doing that is itself an infringement of a right of the fat man’s. By contrast, the means by which the agent in Bystander at the Switch gets the trolley to threaten one instead of five include no more than getting the trolley off the straight track onto the right-hand track; and doing that is not itself an infringement of a right of anybody’s. [1411]
It is arguable, however, that what is relevant is not that toppling the fat man off the footbridge is itself an infringement of a right of the fat man’s but rather that toppling him off the footbridge is itself an infringement of a particularly stringent right of his.
What I have in mind comes out in yet another variant on Bystander at the Switch. Here the bystander must cross (without permission) a patch of land that belongs to the one in order to get to the switch; thus in order to get the trolley to threaten the one instead of five, the bystander must infringe a right of the one’s. May he proceed?
Or again, in order to get the switch thrown, the bystander must use a sharply pointed tool, and the only available sharply pointed tool is a nailfile that belongs to the [72]one; here too the bystander must infringe a right of the one’s in order to get the trolley to threaten the one instead of five. May he proceed?
For my own part, I do not find it obvious that he may. (Remember what the bystander will be doing to the one by throwing that switch.) But others tell me they think it clear the bystander may proceed in such a case. If they are right – and I guess we should agree that they are – then that must surely be because the rights which the bystander would have to infringe here are minor, trivial, non-stringent – property rights of no great importance. By contrast, the right to not be toppled off a footbridge onto a trolley track is on any view a stringent right. We shall therefore have to recognize that what is at work in these cases is a matter of degree: If the agent must infringe a stringent right of the one’s in order to get something that threatens five to threaten the one (as in Fat Man), then he may not proceed, whereas if the agent need infringe no right of the one’s (as in Bystander at the Switch), or only a more or less trivial right of the one’s (as in these