given the title of the thread, i am going to assume the aim was for a Bayesian argument. and suggest none exists. that none can exist given the details
Toontown presented (thanks for those). then i'll suggest we might want to think of this from a freqentist perspective, which is a bit weird but might prove interesting to discuss...
accuse me of 'jumping from properties of "before" to properties of "after" and having agreed the two states differ, then using aspects of them simultaneously.'
I will try and say this more clearly, but you have made it clear your are trying to use the Bayesian framework in a manner it does not allow.
just to be clear, BEFORE refers to the state of affairs prior to the time of the event/non-event and AFTER refers to the state of affairs after the time of the event/non-event.
We agree the probability BEFORE some event is small, call it "p"; and that the probability AFTER the event is, well one, if the event happened and zero if it did not.
from these and other quotes:
Whenever someone is lucky enough to exist, skeptical enough to be suspicious, and decides to question the hypothesis.
"You" is roughly defined as a sentient experience which is actually experienced
it is clear that you are discussing the probability of existing AFTER "someone"/"you"/... exist
as the hypothesis involves you reflecting on the chance of your coming into being, then for the Bayesian this is AFTER and the probability is one. end of argument.
what the probability was BEFORE doesn't enter into it, but reflection regarding it brings the Bayesian no surprise: given that she knows "a sentient experience" can happen. if we are willing to agree that Bayesians are sentient. i am.
so you may have seen this coming. you will no doubt cry foul, but it will not help you if you stay in the Bayesian framework
You gotta have an observation.
this is true, (have one or expect one) but in this case "you" are the observation. the entire set up is AFTER. the only probability is one.
That's right, only people who've "beaten the odds" can do the test, because they're the ones who have observations. But then, anyone who has any observation of any kind has beaten the odds against having said observation.
none of this changes the Bayesian picture. it seems a bit unfair, of course. but the thread selected the Bayesian framework.
Or pretty damn obvious, like the moon. Only people who exist can look at the moon.
and only people who exist can take the Bayesian way.
but questions regarding your own existence are NOT obvious in the way questions about the moons existence are obvious. one can ask the probability that the moon does not exist a the moment. or will not rise tomorrow. since the moon is external to the entity forming the question, Bayes is happy.
(there must be threads somewhere on this site discussing the probability that man has never gone to the moon. (interesting that that is an AFTER, but leave it for later).)
so what would a frequentist say? i think you could avoid the BEFORE/AFTER dead end if you dropped the Bayesian perspective (which i do not think has been important to any critical step in this thread) and framed the argument as a frequentist. it may not get you where you want to go, but there is no Bayesian argument that will support you.