> Demonic Test strikes me as even more unlikely. However unlikely it is that the mugger has magical demonic powers, the Test hypothesis requires the *additional* implausibility of their lying about their plans for no obvious reason.
I'm actually not sure we do have any rational grounds for thinking that Demonic Test is more unlikely. It's…
> Demonic Test strikes me as even more unlikely. However unlikely it is that the mugger has magical demonic powers, the Test hypothesis requires the *additional* implausibility of their lying about their plans for no obvious reason.
I'm actually not sure we do have any rational grounds for thinking that Demonic Test is more unlikely. It's not as if Demonic Test includes everything that is implausible about Demonic Mugger, *plus* an additional implausibility. The implausibilities are just different. In Demonic Mugger we have to ask "why might it be that this mugger has crazy evil powers, and will punish me for refusing his threat?" (Maybe he somehow can't use his powers to get the money himself, and he has to carry out his threats in order to guarantee future compliance. Absurdly unlikely, but perhaps!) In Demonic Test we have to ask, "why might it be that this mugger has crazy evil powers, and will punish me for complying with his threat"? (Maybe he hates people who are weak and spineless, or who are irrational from the standpoint of decision theory. Again absurdly unlikely, but perhaps!) The possibilities we are considering are simply different. The Demonic Test scenarios aren't just (Demonic Mugger + something else). It's hard to say anything about their likelihoods, other than they are all absurdly unlikely. So it's not clear to me that one is more likely than the other.
> "That sort of abstract theoretical claim strikes me as much less trustworthy."
Does it seem more trustworthy when we assume that the low expected utility is finitely small? I was assuming that your credence in the mugger's threat is finitely small, because I think weird things happen if it's infinitesimal. E.g. if your credence is infinitely small, then for you nothing will count as evidence in favor of the mugger's threat (I think?) Could definitely be mistaken about this! Anyway thanks for the response.
> "It's hard to say anything about their likelihoods, other than they are all absurdly unlikely. So it's not clear to me that one is more likely than the other."
Yeah, I agree it's not clear. But it's especially not clear that they are precisely equal in likelihood. And if Test is even *slightly* more unlikely then the cancelling out move fails.
> "Does it seem more trustworthy when we assume that the low expected utility is finitely small?"
Probably, but I don't think we should assume that the mugger's claim warrants finite credence. I'm dubious of the Bayesian claim that nothing can count as evidence for zero probability events.
Simple counterexample: suppose God runs a fair lottery over the natural numbers. You should assign p = 0 that the number 1 will be picked (any finite credence would be too large). Then God tells you that the winning number was, in fact, 1. You should now assign this much higher credence. It's difficult to model this mathematically. But it seems clearly correct nonetheless.
> Demonic Test strikes me as even more unlikely. However unlikely it is that the mugger has magical demonic powers, the Test hypothesis requires the *additional* implausibility of their lying about their plans for no obvious reason.
I'm actually not sure we do have any rational grounds for thinking that Demonic Test is more unlikely. It's not as if Demonic Test includes everything that is implausible about Demonic Mugger, *plus* an additional implausibility. The implausibilities are just different. In Demonic Mugger we have to ask "why might it be that this mugger has crazy evil powers, and will punish me for refusing his threat?" (Maybe he somehow can't use his powers to get the money himself, and he has to carry out his threats in order to guarantee future compliance. Absurdly unlikely, but perhaps!) In Demonic Test we have to ask, "why might it be that this mugger has crazy evil powers, and will punish me for complying with his threat"? (Maybe he hates people who are weak and spineless, or who are irrational from the standpoint of decision theory. Again absurdly unlikely, but perhaps!) The possibilities we are considering are simply different. The Demonic Test scenarios aren't just (Demonic Mugger + something else). It's hard to say anything about their likelihoods, other than they are all absurdly unlikely. So it's not clear to me that one is more likely than the other.
> "That sort of abstract theoretical claim strikes me as much less trustworthy."
Does it seem more trustworthy when we assume that the low expected utility is finitely small? I was assuming that your credence in the mugger's threat is finitely small, because I think weird things happen if it's infinitesimal. E.g. if your credence is infinitely small, then for you nothing will count as evidence in favor of the mugger's threat (I think?) Could definitely be mistaken about this! Anyway thanks for the response.
> "It's hard to say anything about their likelihoods, other than they are all absurdly unlikely. So it's not clear to me that one is more likely than the other."
Yeah, I agree it's not clear. But it's especially not clear that they are precisely equal in likelihood. And if Test is even *slightly* more unlikely then the cancelling out move fails.
> "Does it seem more trustworthy when we assume that the low expected utility is finitely small?"
Probably, but I don't think we should assume that the mugger's claim warrants finite credence. I'm dubious of the Bayesian claim that nothing can count as evidence for zero probability events.
Simple counterexample: suppose God runs a fair lottery over the natural numbers. You should assign p = 0 that the number 1 will be picked (any finite credence would be too large). Then God tells you that the winning number was, in fact, 1. You should now assign this much higher credence. It's difficult to model this mathematically. But it seems clearly correct nonetheless.