🚀 go-pugleaf

In article <1992Sep22.175911.1375@guinness.idbsu.edu> holmes@opal.idbsu.edu (Randall Holmes) writes:
>In article <BuypA4.K9p@usenet.ucs.indiana.edu> chalmers@bronze.ucs.indiana.edu (David Chalmers) writes:
>[...]
>>So, in this case, I'm asserting the logical possibility of a zombie
>>replica of me, which certainly *seems* coherent.  The burden on
>>those who dispute this is to provide the slightest idea of
>>how it might entail a contradiction, or equivalently, how the
>>physical facts might entail the facts about consciousness.  This
>>is what they've manifestly failed to do.
>
>It entails a contradiction if the facts in the two cases are _the same
>facts_; you can only assume that it is _possible_ that they are
>different if they are in fact different. 

When you say it this way ("possible that they are different"), 
you seem to be talking about whether it is possible in the actual
world, meaning : it is possible that it is the case in the actual
world?  When we talk like this we usually mean something like
"given what we know, it it possible that...".  For instance,

   Is it possible that the man seen outside the shop and the
   man who killed the shopkeeper are the different?

Once we find out they're the same, we stop think it's possible
that they're different.  So possibility comes in as a sort of
epistemic possibility.

But the issue of logical possibility is quite different.  Even 
if in this (actual) world the man seen outside the shop and the
man who killed the shopkeeper are the same, there are other
logically possible worlds in which they are not the same.
For instance, the killer might go out the back and not be seen
while someone else walked out the front.  This is the sort of
possible we have in mind when we ask "Could Ford have beaten
Carter?" and not when we ask "Could Ford be someone other
than himself?"

-- jd