## Monday, August 1, 2022

### Triple effect, looping trolley and felix culpa

Frances Kamm uses her principle of triple effect to resolve the loop version of the trolley problem. On the loop version, as usual, the main track branches into are two tracks, track A with five people and track B with one person, and the trolley is heading for track A. But now the two tracks join via a loop, so if there were no one on either track, a trolley that goes on track A will come back on track B and vice versa. If we had five people on track A and no one on track B, and we redirected the trolley to track B, it would go on track B, loop around, and fatally hit the people on track A anyway. But the one person actually on track B is big enough that if the trolley goes on track B, it will be stopped by the impact and the five people will be saved.

The problem with redirecting to track B on the loop version of the trolley problem is that it seems that a part of your intention is that the trolley should hit the person on track B, since it is that impact which stops the trolley from hitting the five people on track A. And so you are intending harm to the person on track B.

In her Intricate Ethics book, Kamm gives basically this story about redirecting the trolley in the loop case:

• Initial Intention: Redirect trolley to track A to prevent the danger of five people being hit from the front.

• Initial Defeater: The five people come to be in danger of being hit from the back by the trolley.

• Defeater to Initial Defeater: The one person on track B blocks the trolley and prevents the dangers of being hit from the back.

The important point here is that the defeater to the defeater is not intended—it is just a defeater to a defeater. Thus there is no intention to block the trolley via the one person on track B, and hence that person’s being hit is not a case of their intentionally being used as a means to saving lives.

But this defeater-defeater story is mistaken as it stands. For given the presence of the person on track B, there is no danger of the five people being hit from the back. Thus, there is no initial defeater here.

Now, if you don’t know about the one person on track B, you would have a defeater to the redirection, namely the defeater that there is danger of being hit from the back. But learning about the person on track B would not provide a defeater to that defeater—it would simply remove the defeater by showing that the danger doesn’t exist.

That the story doesn’t have a defeater-defeater structure does not mean that one is intending the one person to be hit. Kamm might still be right in thinking there is no intention to block the trolley via the one person on track B. But I am dubious of Kamm’s story now, because I am dubious that the danger of being hit from the front yields a worthy initial intention. For there is nothing particularly bad about being hit from the front. It is only the danger of being hit simpliciter that seems worth preventing.

It is interesting to me to note that even if Kamm’s story doesn’t have defeater-defeater form, the main place where I want to use her triple effect account seems to still have defeater-defeater form. That place is the felix culpa, where God allows Adam and Eve to exercise their free will, even though he knows that this would or might well (depending on details about theories of foreknowledge and middle knowledge) result in their sinning, and God’s reasoning involves the great goods of salvation history that come from Adam and Eve’s sin.

• Initial Intention: Allow Adam and Eve to exercise their free will.

• Initial Defeater: They will or might well sin.

• Defeater to Initial Defeater: Great goods will come about.

Here the initial defeater is not mistaken as in the looping trolley case—the sin or its possibility is really real. Moreover, while it’s not an initially worthy intention to prevent people from being hit from the front, unless they aren’t going to be hit from behind (or some other direction) either, it is an initially worthy intention to allow Adam and Eve to exercise their free will, even if no further goods come about, because free will is intrinsically good.

Thus we can criticize Kamm’s own use of triple effect while yet preserving what I think is a really important theological application.

Unknown said...

How do I read The Existence of God (coedited with R. M. Gale)? where is the pdf?

Alexander R Pruss said...

It's out of print. I have one hard copy. For copyright reasons, I can't make a PDF available.

Michael Birdwell said...

Wow, I was just thinking of asking the same question a few days ago.

Harrison Lee said...

Suppose a defeater of a primary intention is a fact which threatens to render the primary intention unreasonable. Then it seems that the defeater of the primary intention is false in the Party Case also (although the notion of "threat" is vague here). That there will be a mess does not threaten to render the intention to throw the party unreasonable. For the agent knows all along that the mess will be cleaned. So, maybe a defeater is just a fact which, *taken on its own* might seem to render the primary intention unreasonable. But then the fact that the trolley is headed toward the five via the loop could plausibly be construed as a defeater in the loop case even though the agent who diverts knows that the trolley will be stopped by the man on the tracks.

Also, here is a variant of the Party Case: Sam throws a party because he knows his friends will feel sufficiently indebted to him that they will never leave a mess in the first place. It is clear that he does not throw the party in order to make his friends feel indebted. This is only desired because it will prevent the party from resulting in a mess--its value is parasitic on the occurrence of the party.

So, an agent might decide to x because of some factor f, not because f solves a problem created by x, but because f prevents x from resulting in problems to begin with. Maybe this suggests that construing the cases in defeater-defeater terminology is mistaken, or maybe it suggests that defeaters are just facts which *taken on their own* seem to render the primary intention unreasonable. If the first of these options is true it is not a problem for Kamm that the defeater is false. If the second is true it is not clear that the defeater is false. In neither case is there a problem here for her view.

I share your suspicion that her application of DTE to the Loop Case fails, but I'm not sure how relevant it is that the defeater is false on a certain construal of what it means to be a defeater.