> -----Original Message-----
> From: Jesse Mazer [mailto:[EMAIL PROTECTED]]
> Sent: Friday, 7 September 2001 6:39 a.m.

> Hmm, I think we actually have a full spectrum of opinions here...Jacques
> believes only in absolute probability, Bruno believes only in conditional
> probabilities, and I believe in both. So, of course, I agree with what Bruno
> said about the importance of conditional probabilities--what happens to me
> after an operation is not a matter of definition--but I also think there
> should be an absolute distribution to tell me how likely it is that I will
> experience one type of observer-moment vs. another in the first place.

It seems to me that "the probability of me experiencing one type of OM" is an 
incoherent notion. It *looks* as though you are saying
that you exist outside OMs in some way, when I see no reason to assume you are 
anything other than a series of OMs. Maybe you aren't
saying that (it also sounds as though the "Bayesian argument" is based on a similar 
(mis)conception).

> I don't really think there's some "other metaphysical realm" where we get
> dropped from, but I do think that, as an analogy, the spotlight one is not
> actually so bad. After all, if you think that you just *are* your current
> observer-moment, how can you possibly become any other one? The
> observer-moment itself doesn't transform--it's just sitting there timelessly
> in Platonia among all other possible observer-moments. So, it's better to
> think of "continuity of consciousness" as a spotlight moving between
> different observer-moments, with the probability of going from one to
> another defined by the conditional probability distribution.

You don't *become* another OM. That's just the fallacy that you exist outside OMs in a 
different disguise. There is no "you" to
"move from one OM to the next" - there is only a stack of OMs, from which the concept 
of "you" emerges as a useful abstraction. The
stack of OMs is linked together by some sort of transition rules (e.g. what we might 
call the "laws of physics" for the sake of
convenience). There must be some sort of "principle of similarity" which allows the 
feeling of continuous consciousness to arise
from the stack.

> Similarly, if you just *are* your current observer-moment with probability
> 1, nothing else can be said, so there doesn't seem to be any way to assign
> meaning to an absolute probability distribution on all observer-moments.

Exactly. Hence my non-acceptance (so far) of the "Bayesian argument" regarding QTI.

> I think it makes more sense to think of this distribution as the probability
> that a randomly-selected spotlight will be shining on a particular
> observer-moment, like in the Hoyle story. If we abandon the idea of an
> absolute probability distribution, we have no hope of explaining why I am
> this particular type of observer-moment experiencing this particular type of
> universe, and we can only explain why my future experience will have a
> certain amount in common with my current experience (assuming that's what
> the conditional probability distribution actually predicts). But plenty of
> observer-moments might find themselves experiencing universes with very
> different laws of physics--why am I experiencing these laws as opposed to
> some other set? Without a global probability distribution this can only be a
> brute fact, unexplained by the TOE. Likewise, why am I experiencing this
> particular era of the universe's history, or this unusual spatial region
> (the surface of a planet containing complex life), or this particular
> organism's point of view (a human vs. some other animal)? In all of these
> cases I think the intuitive explanation is something like the "anthropic
> principle" or the "self-sampling assumption" (this term is explained on
> http://www.anthropic-principle.com by Nick Bostrom, for anyone who's not
> familiar with it), and my hope is that the global probability distribution
> would incorporate a formalized version of something like this. But without
> such a global probability distribution, all this stuff becomes just more
> brute facts.

Why does the fact that you are "this particular type of observer-moment experiencing 
this particular type of universe" NEED further
explanation? I mean apart from the sort of explanation we use to explain why, say, a 
particular rock is found in a particular
space-time location?

> Just because something has probability 1 from your current point of view, I
> don't think that means it should be treated as a brute fact.
> If so, all historical scientific theories would be
> pointless--cosmologists would be out of a job, for example.

You are attacking a "straw man" here (i.e. putting words and views into the mouths of 
those you disagree with). Everything in the
universe is a "brute fact" - the universe (or multiverse) *is* in actual fact in a 
particular state - but that doesn't stop us
trying to explain how it came to be that way. If you *are* simply a stack of observer 
moments, that fact doesn't somehow invalidate
the entire scientific endeavour, it's just a fact which still has consequences and 
requries explanation and so on. Similarly, if the
Hoyle spotlight turns out to be fictitious (as it was intended to be, since it 
appeared in a novel - as was his "consciousness
field" which appeared in "Fifth planet" :-) that doesn't make the whole edifice of 
science collapse, no more than it collapsed when
phlogiston or the aether turned out not to exist.

Charles

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