Le 21-juin-05, à 21:21, Pete Carlton a écrit :
> I think the practical differences are large, as you say, but I
> disagree that it points to a fundamental metaphysical difference. I
> think what appears to be a metaphysical difference is just the
> breakdown of our folk concept of "I". Imagine a primitive person who
> didn't understand the physics of fire, seeing two candles lit from a
> single one, then the first one extinguished - they may be tempted to
> conclude that the first flame has now become two flames. Well, this
> is no problem because flames never say things like "I would like to
> keep burning" or "I wonder what my next experience would be". We,
> however, do say these things. But does this bit of behavior
> (including the neural activity that causes it) make us different in a
> relevant way? And if so, how?
>
> This breakdown of "I" is very interesting. Since there's lots of talk
> about torture here, let's take this extremely simple example: Smith is
> going to torture someone, one hour from now. You may try to take
> steps to prevent it. How much effort you are willing to put in
> depends, among other things, on the identity of the person Smith is
> going to torture. In particular, you will be very highly motivated if
> that person is you; or rather, the person you will be one hour from
> now. The reason for the high motivation is that you have strong
> desires for that person to continue their life unabated, and those
> desires hinge on the outcome of the torture. But my point is that
> your strong desires for your own survival are just a special case of
> desires for a given person's survival - in other words, you are
> already taking a third-person point of view to your (future) self.
> You know that if the person is killed during torture, they will not
> continue their life; if they survive it, their life will still be
> negatively impacted, and your desires for the person's future are
> thwarted.
>
> Now, if you introduce copies to this scenario, it does not seem to me
> that anything changes fundamentally. Your choice on what kind of
> scenario to accept will still hinge on your desires for the future of
> any persons involved. The desires themselves may be very complicated,
> and in fact will depend on lots of hitherto unspecified details such
> as the legal status, ownership rights, etc., of copies. Of course one
> copy will say "I pushed the button and then I got tortured", and the
> other copy will say "I pushed the button and woke up on the beach" -
> which is exactly what we would expect these two people to say. And
> they're both right, insofar as they're giving an accurate report of
> their memories. What is the metaphysical issue here?
There are two *physical* issues here.
1) The simplest one is that if you agree with the comp indeterminacy
(or similar) you get an explanation of the quantum indeterminacy
without the collapse of the wave packet. This is mainly Everett
contribution.
2) The less trivial one, perhaps, is that if you agree with the comp
indeterminacy you get an a priori explosion of the number of
appearances of first person white rabbits and the only way to solve
this, assuming the SWE is correct, must consist in justifying the SWE
from the comp indeterminacy bearing on all computational
states/histories.
The issue "1)" is that an indeterministic physical theory is reduced to
a deterministic physical theory.
The issue "2)" is that physics is reduced (at least in principle) to
math/computer science.
Bruno
http://iridia.ulb.ac.be/~marchal/
Received on Wed Jun 22 2005 - 04:17:33 PDT