[ertgbnm]

The underlying assumption is that Bentham is a true act utilitarian yet simultaneously has 10 pounds in his pocket that he can stand to lose without much harm. If he truly were an act utilitarian, the utility of the 10 pounds remaining in Bentham's possession must be so high that it outweighs the mugger losing their finger, otherwise Bentham would have already spent it on something similarly utility maximizing. Clearly that 10 pounds was already destined to maximize utility such as staving off Bentham's hunger and avoiding his own death or the death of others.

Meanwhile the utility of the mugger's finger is questionable. The pain of losing the finger is the only real cost. If they are just a petty criminal, the loss of their finger will probably reduce their ability to commit crimes and prevent him from inflicting as much suffering on others as he otherwise would have. Maybe losing his finger actually increases utility.

Bentham: "I'm sorry Mr. Mugger but I am on my way to spend this 10 pounds on a supply of fever medication for the orphanage and I am afraid that if I don't procure the medicine, several children will die or suffer fever madness. So when faced with calculating the utility of this situation I must weigh your finger against the lives of these children. Good day. And if the experience of cutting your finger off makes you question your own deontological beliefs, feel free to call upon me for some tutoring on the philosophy of Act Utilitarianism."

Any other scenario and Bentham clearly isn't a true Act Utilitarian and would just tell the Mugger to shove his finger up his ass for all Bentham cares. Either strictly apply the rules or don't apply them at all.

[jfengel]

It's for this reason that I find all forms of Utilitarian less edifying than I would hope. They can put intuitively moral choices on a clear, explicit footing, but they produce counterintuitive results in less clear cases. Those less clear cases are precisely what you'd want a Utilitarian system to solve, since you don't really need to make much effort to justify clear cases.

They tend to look best on the moral equivalent of PowerPoint slides. But if you look beyond toy examples, nearly everything is too complex to believe that you've really formed a decent model of the situation. Without that model you're stuck where you were without the Utilitarian principles.

It's fun to argue about but I don't think it makes for a pragmatic moral system. And it's easily subverted by people claiming to present a moral case that is in fact incomplete, leading to abhorrent conclusions that they feel rigorously bound by.

[MichaelZuo]

> They tend to look best on the moral equivalent of PowerPoint slides.

This is an interesting formulation, when you put that way I imagine most readers have seen some 'moral powerpoint slides' that fall apart on a closer examination.

[why_at]

I get what you mean. Whenever I read one of these scenarios that tries to show some absurd conclusion about a moral theory like utilitarianism, it makes me wonder if there is something about the outlandishness of the situation that makes it hard for our mental heuristics to work properly. In this case it's the idea that Bentham is a perfect act utilitarian, that the mugger will 100% follow through on his promise, that it won't affect anything else in the future besides the immediate suffering etc.

That said, I am doing my best to come up with an example that avoids the problem you mention. If we can imagine a utopia society where everyone is a perfect act utilitarian except the mugger, and all resources are distributed in a totally fair way such that any $10 will buy much less utility than saving a finger, the mugger's tactic would be harder to avoid.

I think the problem I still have with this is that it's basically saying that it's possible for a jerk to take advantage of a bunch of nice people, which isn't that interesting of a conclusion.

[tuatoru]

> scenario that tries to show some absurd conclusion about a moral theory

So, the trolley problem? "Philosophy is bunk".

[gs17]

> Meanwhile the utility of the mugger's finger is questionable. The pain of losing the finger is the only real cost. If they are just a petty criminal, the loss of their finger will probably reduce their ability to commit crimes and prevent him from inflicting as much suffering on others as he otherwise would have. Maybe losing his finger actually increases utility.

Yes, the mugger removing his own finger, in Bentham's words, would "prevent the happening of mischief, pain, evil, or unhappiness", assuming the mugger is going to continue a life of crime where fingers help him. If the mugger was a pediatric surgeon who was performing a one-time theft (and we can trust him to never do it again) to get some quick cash on his way to work it might work. It doesn't resolve what the money was originally for, but at least that finger could be as important as your medicine.

[ertgbnm]

Yeah, but now we are in rather hilarious territory. Act Utilitarians can be taken advantage of by deontologist pediatric surgeons, but only once per surgeon per utilitarian. Much less of a gotcha than the original formulation of Bentham's Mugging.