[ameliaquining]

The problem here isn't with the main character's moral philosophy, but with his decision theory. He'd be dealing with exactly the same predicament if the mugger were threatening to harm him.

The solution is indeed "don't give in to muggers", but it's possible to define this in a workable way. Suppose the mugger can choose between A (don't try to mug Bentham) or forcing Bentham to choose between B (give in) or C (don't give in). A is the best outcome for Bentham, B the best outcome for the mugger, and C the worst for both. The mugger, therefore, is only incentivized to force the choice if he expects Bentham to go for B; if he expects Bentham to go for C, then it's in his interest to choose A. Bentham, therefore, should have a policy of always choosing C, if it's worse for the mugger than A; if the mugger knows this and responds to incentives (as we see him doing in the story), then he'll choose A, and Bentham wins.

And none of this has anything to do with utilitarianism, except in the respect that utilitarianism requires you to make decisions about which outcomes you want to try to get, just like any other human endeavor.

[tylerhou]

It does have to do with utilitarianism — if you change the mugger to harming Bentham, the situation is different. In that situation, many other reasonable moral theories would agree with utilitarianism.

In the original situation, where the mugger is harming themselves, the critique is that utilitarianists are required to treat their own interests as exactly the same as other people’s interests. It doesn’t matter if someone is harming themselves in order to provoke some action from you; if your action prevents that harm, you are obligated to do that action (even if you suffer because of it).

[Micaiah_Chang]

Yes, the point of the GP comment is exactly this, if Bentham becomes an agent that goes for C, he also explicitly discourages the mugger from being an agent that would cut off their fingers for a couple of bucks.

Notice that what Bentham is altering is their strategy and not their utility. If they could spend 10 dollars to treat gangrene and save the fingers, they would do it. It's not clear many other morality systems would be as insistent on this as utilitarianism, because practitioners of other moralities curiously form epicycles defending why the status quo is fine anyway, how dare you imply I'm worse at morality.

Edit: Slight wording change for clarity

[tylerhou]

> if Bentham becomes an agent that goes for C, he also explicitly discourages the mugger

How is this different from saying that if Bentham decides to not adhere to utilitarianism, he is no longer vulnerable to such a mugging? If Bentham always responds C, even when actually confronted with such a scenario (the mugger was not deterred by Bentham's claim), then Bentham is not a utilitarianist.

In other words, the GP is saying: "if Bentham doesn't always maximize the good, he is no longer subject to an agent who can abuse people who always maximize the good." But that is exactly the point -- that utilitarianism is uniquely vulnerable in this manner.

[Micaiah_Chang]

My wording is wrong, because it sounds like I'm saying that Bentham is adopting the policy ad hoc. A better way to state this is that Bentham starts out as an agent that does not give into brinksmanship type games, because a world where brinksmanship type games exist is a substantially worse world than ones where they don't (because net-negative situations will end up happening, it takes effort to set up brinksmanship and good actions do not benefit more from brinksmanship). It's different because by adopting C, Bentham prevents the mugger from mugging, which is a better world than one where the mugger goes on mugging. I don't see any contradiction in utilitarianism here.

If the world where the thought experiment is not true and "mugging" is net positive, calling it mugging then is disingenuous, that's just more optimally allocating resources and is more equivalent to the conversation "hi bentham i have a cool plan for 10 dollars let me tell you what it is" "okay i have heard your plan and i think it's a good idea here's 10 bucks"

Except that you are putting the words "mugging" and implying violence so that people view the interaction as more absurd than it actually is.

[tylerhou]

> It's different because by adopting C, Bentham prevents the mugger from mugging, which is a better world than one where the mugger goes on mugging.

This assumption is wrong. You are assuming that the mugger is also a utilitiarian, so will do cost-benefit analysis, and thus decide not to mug. But that is not necessarily true.

If the mugger mugs anyway, despite mugging being "suboptimal," Bentham ends up in a situation where he has exactly the same choice: either lose $10, or have the mugger cut off their own finger. If Bentham is to follow (act-)utilitarianism precisely, he must pay the mugger $10. (Act-)utilitarianism says that the only thing that matters is the utility of the outcome of your action. It does not matter that Bentham previously committed to not paying the mugger; the fact is, after the mugger "threatens" Bentham, if Bentham does not pay the mugger, total utility is less than if he does pay. So Bentham must break his promise, despite "committing" not to. (Assuming this is some one-off instance and not some kind of iterated game; iteration makes things more complicated.)

(In fact, this specific objection -- that utilitarianism requires people to "give up" their commitments -- is at the foundation of another critique of utilitarianism by Williams: https://123philosophy.files.wordpress.com/2018/12/bernard-wi...)

If everyone were a utilitarian, then there would be far fewer objections to utilitarianism. (E.g. instead asking people in wealthy countries to donate 90% of their income to charity, we could probably get away with ~5-10%.) Bentham's mugging is a specific objection to utilitarianism that shows how utilitarians are vulnerable to manipulation by people who do not subscribe to utilitarianism.

Also, to be precise, Bentham's mugging does not show a contradiction. It's showing an unintuitive consequence of utilitarianism. That's not the same thing as a contradiction. (If you want to see a contradiction, Stocker has a different critique: https://www.jstor.org/stable/2025782.)

[kelnos]

Except that eventually the mugger will run out of fingers (and/or reattaching them will eventually start not working out), so the mugger will be forced to stop mugging. Well, ok, they could start cutting off toes, or threaten some other form of bodily mutilation.

But regardless, giving in to the mugger enables the mugger to continue mugging indefinitely. Not giving in -- assuming the mugger goes through with whatever self-mutilation they've threatened -- will eventually cause the mugger to stop mugging. This would be a net positive, better than allowing the mugger to mug indefinitely.

On top of that, I was disappointed that, in the story, Bentham does actually bring up the idea that capitulating could encourage copycats to run similar schemes, but this rationale for not cooperating is hand-waved away. This is pretty standard "don't negotiate with terrorists" stuff. Giving in just tells the mugger -- and other potential muggers -- that this strategy works. Surely it's more utilitarian to stamp this out at the source, even if it costs the original mugger some fingers.

(But I guess this is in part the point of Bentham being an act utilitarian in the first encounter, as he wouldn't consider the larger implications of his actions, just on the specific, immediate result of the action in front of him.)

[slibhb]

> practitioners of other moralities curiously form epicycles defending why the status quo is fine anyway

This is exactly what the Bentham in the story is doing!

[wzdd]

> none of this has anything to do with utilitarianism

"Always go for C (or any strategy)" is not in general a utilitarian strategy, so the mugger would not expect Bentham to employ it.

Your argument assumes that the characters have perfect knowledge, but the point of the parody is that utilitarian choices can change as more information is revealed.

Yes, the mugger could have said something like "if I were to promise to cut off my finger unless you gave me £10, would you do it?", Bentham could have have followed up with "if you knew I would reply no to that question, would you make that promise?", the mugger could have replied "no," Bentham could have responded "In that case, no", and the mugger would have walked away. But Bentham doesn't have all the information until he is faced with the loss of a finger which he can prevent by giving up £10. Bentham is obliged to do so, as it maximises the overall good at that (unfortunate) point.

The idea that Bentham can be "trapped" in a situation where he is obliged to cause some small harm to himself in order to prevent a greater harm is the parody of utilitarianism which is at the heart of the story.

[amalcon]

The mugger in the story is essentially contriving a situation that turns him into a utility monster. He is arranging that he will derive more benefit from the money than any other plausible application -- by imposing a massive harm on himself if he doesn't get the money. It's relatively straightforward to vary the threat to adjust incentives as necessary -- e.g. the binding deal with the thug later in the story.

[schoen]

One related way to think about this is that, if (non-utilitarian) people are ever able to change their own utility functions, other people's utilitarianism gives them an incentive to do so, because it can make them more likely to get what they want.

For example, if you can learn to feel sadder about something, other people who want to minimize your sadness will acquire an incentive to help you avoid that thing, even at some cost to themselves.

In many moral intuitions, you find the world as it is and then act on it in some way, without other people strategizing about, or being incentivized by, your moral reasoning. But when other people can do those things, you can get very weird outcomes.

[slibhb]

The mugger cuts off his own fingers when a different utilitarian doesn't pay him. Given that, and given that he's right back at it after surgery, I don't think it's so clear that he'll "respond to incentives" and stop mugging people if people stop giving in.

After all, one of the premises here is that the mugger is a deontologist. He doesn't care about outcomes.