I’m a little puzzled why I’m having to point this out
You’re having to point it out because you kept emphatically insisting on the opposite! But now you’ve clarified that obviously we can and do have evidence about future events that are not fully predictable, I don’t understand how this strand of your argument holds together. It was presented as support for this claim:
Statements like “by definition, “I am in the first 10% of people” is false for most people” are incompatible with Bayesianism: you just broke one of its fundamental assumptions: causality. What you meant was “By definition, “He was in the first 10% of people” will, once we’re extinct, turn out to have been false for most people.” — I hope that careful distinction makes it entirely clear why the Doomsday Argument is nonsense?
You haven’t explained why that temporal distinction is so crucial, and why this rephrasing doesn’t serve the same purpose as the original statement in the doomsday argument:
“By definition, “I will eventually turn out to have been in the first 10% of people” will eventually turn out to have been false for most people”
As far as I’m concerned, “I will eventually turn out to have been in the first 10% of people” is obviously what “I am in the first 10% of people” meant in the first place. So what’s the important difference here?
(All claims about the future are claims about what will eventually turn out to be the case, and arguably all are also claims about what will eventually turn out to have been the case, i.e. that present conditions were such as to lead to the later outcomes. I feel like maybe there’s an important disagreement, or misunderstanding on my part, adjacent to this, but I can’t pin it down based on what you’ve written.)
One thing I should check, since we got tripped up once on absolutes: are you saying the doomsday argument is simply invalid and has literally no bearing on your probabilities? Or are you saying it has non-zero but negligible force?
(I didn’t downvote you, by the way; although we’re evidently both finding this a bit frustrating, I appreciate your sincere engagement throughout this discussion! No pressure to keep responding, though, if you feel it’s no longer worthwhile.)
Yes, I get it, I’m very ignorant. (If you needed to get that off your chest, you could perhaps have said it directly in one sentence, rather than spending 10000 words patiently implying it.) But you’re still handwaving the interesting parts.
Obviously “I am in the first 10% of people” is a prediction; I already agreed to rephrase it as “I will eventually turn out to have been in the first 10% of people”. I’m not trying to deduce anything from the fact that it ‘sounds implausible’, and I’m not trying to bring any information back in time from the moment it turns out to be true or false in my case. I’m noting that it will definitely turn out to be false from the perspective of 90% of people who ever live, and asking why *this* fact is obviously irrelevant to the credence I should give it.
The answer is not “bayesianism, obviously”. Bostrom, even back when he was writing about this stuff, was not a heathen frequentist, and he wasn’t as stupid as me. (I’m pretty sure he’d even heard of causality.)