Furthermore, more significantly, under MWI it is not even clear what first two statements could even mean.
Then we can pardon Bostrom for not taking them into account.
I take the http://en.wikipedia.org/wiki/Nick_Bostrom to be at least somewhat representative of his contribution to simulation argument
Wikipedia is pretty bad on philosophy (the SEP is much better), and in this case, there's no reason not to read Bostrom's original paper and the correction: he writes clearly, and they are readily available on his website.
In such case there is the fourth possibility with probability overwhelmingly higher than of this entire argument: the wild guess that there would ever be a good reason to believe that we should be among most numerous, with same weight for real thing and simulator (or same weight for different types of simulator), is not spot on. Collaborated also by us not being among those in weird sims of any kind (we'd detect a god speaking to us every day).
What? Could you write this more clearly, I have no idea what you're trying to say.
Those who aren't grossly wrong (Newton for example) don't look as silly as the silly I am speaking of.
Newton is actually a great example; if you don't choose to ignore the areas which make him look bad, he looks like an incredible fool in many respects. His constant pursuit of alchemy even then was the object of derision, and while we no longer would hang or exile him for his bizarre theology & eschatology, we (even most Christians) would regard them as hilarious. Then there are his priority disputes...
If even Newton looks this foolish, what hope can the rest of us have? No, the suggestion 'would this make me look foolish in 100 years?' does us no good in practice.
Then we can pardon Bostrom for not taking them into account.
When pondering the possibilities where we live given lack of grand unified theory 'of everything', you can't assume your physical intuitions hold true. In fact you should assume the opposite. The MWI is just an example of how philosophical argument that looks entirely invariable admits defeat from possible physics, in a way in which the mathematics - which philosophy mimics - does not. That means validity of argument requires validity of intuitions, which are reasonably very unlikely to be vali...
Nick Szabo on acting on extremely long odds with claimed high payoffs:
Beware of what I call Pascal's scams: movements or belief systems that ask you to hope for or worry about very improbable outcomes that could have very large positive or negative consequences. (The name comes of course from the infinite-reward Wager proposed by Pascal: these days the large-but-finite versions are far more pernicious). Naive expected value reasoning implies that they are worth the effort: if the odds are 1 in 1,000 that I could win $1 billion, and I am risk and time neutral, then I should expend up to nearly $1 million dollars worth of effort to gain this boon. The problems with these beliefs tend to be at least threefold, all stemming from the general uncertainty, i.e. the poor information or lack of information, from which we abstracted the low probability estimate in the first place: because in the messy real world the low probability estimate is almost always due to low or poor evidence rather than being a lottery with well-defined odds.
Nick clarifies in the comments that he is indeed talking about singularitarians, including his GMU colleague Robin Hanson. This post appears to revisit a comment on an earlier post:
In other words, just because one comes up with quasi-plausible catastrophic scenarios does not put the burden of proof on the skeptics to debunk them or else cough up substantial funds to supposedly combat these alleged threats.