In approximate order of your objections to the hypothetical:
Tyrrell, it's not my fault if you can't handle reasoning from hypotheticals, but it certainly doesn't make that form of reasoning -- used in the rest of the civilized world -- off-limits. If you think the analogy I'm making doesn't hold, you can politely show where it breaks down. I had already attempted to speak to the specific situation in dispute -- about religion -- but in that case it's less obvious how one's actions aren't following from one's beliefs if the professed beliefs are the real ones.
I actually think it's obvious enough why actual beliefs in (certain religions') doctrine of eternal hellfire would logically imply a direct transition to an ascetic lifestyle or other drastic choices, and we can go that route if it keeps things in your comfort zone.
But the point is pretty simple: in the hypothetical, we can quite easily draw conclusions: either a) the person doesn't actual have an internal predictive model of reality including a deadly bed monster, or b) he has some kind of weird psychology.
In short, you go with b) and I go with a). Which is why I think this kvetching about hypotheticals suddenly being off-limit is moot: even when I make the situation "more favorable" to my theory, you just bite a bigger bullet, cutting off whatever implication I would have claimed follows back to the original topic of religion.
So, let's review that position:
Another possibility is that, although he doesn't want to die, he prefers it to sleeping somewhere other than his bed. Perhaps sleeping elsewhere seems, to him, a fate worse than death. Since I'm manifestly dealing with a crazy person, that remains a real possibility, at least until I learn more about how he thinks.
The more someone professes different beliefs from yours, the more evidence there is that their mind works differently from yours in some crucial respect, and so the less credit you should give to your mental model of them.
But note the difficult position you've forced yourself into. You have to believe he is obviously crazy despite:
not being obviously crazy in any other area of his life
the psychological unity of mankind somehow breaking for a huge class of people that have been interbreeding with the rest of humankind and whom no one seriously suggests mandatory psychotherapy
his mental model of other phenomena (let's reasonably suppose) being superior to yours in several areas
his actions associated with these "beliefs" greatly helping him achieve many non-crazy personal goals: having a social network, meeting a compatible spouse, greater assurance of spousal fidelity, the feeling of belonging.
the similarity (discussed before) between him and the uncountable historical instances of people supposedly going to great lengths for inscrutable theological doctrines, but actually protecting a meme they benefit from.
Do you see why this is an implausible chain to follow? Especially when the alternative is the majestically simple "Belief means something different in this context that is not an internal predictive model of reality"?
Tyrrell, it's not my fault if you can't handle reasoning from hypotheticals, but it certainly doesn't make that form of reasoning -- used in the rest of the civilized world -- off-limits.
Hypotheticals have their uses, but they are easy to abuse. Hypotheticals are usually fine for
making the meaning of a claim clear by putting it in a simpler context (e.g., explaining the physics of a pendulum by imagining that it has an inelastic and frictionless rod), and
constructing counter-examples to absolute claims (e.g., "Stealing is always wrong!" &
Anticipation and faith are both aspects of the human decision process, in a sense just subroutines of a larger program, but they also generate subjective experiences (qualia) that we value for their own sake. Suppose you ask a religious friend why he doesn’t give up religion, he might say something like “Having faith in God comforts me and I think it is a central part of the human experience. Intellectually I know it’s irrational, but I want to keep my faith anyway. My friends and the government will protect me from making any truly serious mistakes as a result of having too much faith (like falling into dangerous cults or refusing to give medical treatment to my children)."
Personally I've never been religious, so this is just a guess of what someone might say. But these are the kinds of thoughts I have when faced with the prospect of giving up the anticipation of future experiences (after being prompted by Dan Armak). We don't know for sure yet that anticipation is irrational, but it's hard to see how it can be patched up to work in an environment where mind copying and merging are possible, and in the mean time, we have a decision theory (UDT) that seems to work fine, but does not involve any notion of anticipation.
What would you do if true rationality requires giving up something even more fundamental to the human experience than faith? I wonder if anyone is actually willing to take this step, or is this the limit of human rationality, the end of a short journey across the space of possible minds?