From: chalmers@bronze.ucs.indiana.edu (David Chalmers)
Subject: Re: Dualism
Organization: Indiana University
Date: Wed, 30 Sep 1992 07:00:20 GMT

In article <1992Sep29.152225.1174@oracorp.com> daryl@oracorp.com (Daryl McCullough) writes:

>>Plausibility arguments are really all that one has to go on in
>>theorizing about consciousness.  Solipsism, to take another
>>position, is consistent with the evidence, but doesn't seem at all
>>likely.
>
>I'm not sure what you mean by "likely" here. I think that the argument
>against solipsism is more based on esthetics or practicality than on
>likelihood (since there is no a priori probability distribution on
>possible worlds). Either we argue: For the world to be like that seems
>arbitrary (which is an esthetic judgement, as far as I can tell), or
>we argue: Assuming I act on the hypothesis that solipsism is right,
>and it turns out to be wrong, then the consequences are much worse
>than the other way around (which is a practical argument). I don't
>see where likelihood comes in.

Well, you can call it aesthetics if you like, or simplicity, or
whatever.  There's no denying that such "aesthetic factors" play
a role in our judgments of *epistemic* likelihood of various
theories all the time.  Take the theory that the world was created
5 minutes ago, with memories and fossil records and all.  No
evidence can disprove this hypothesis, but I take it that none
of us believe it.  And not just for "practical reasons".  We
really think that epistemically, it's mostly unlikely that this
theory is the correct one.  In general, such "aesthetic"
considerations are all one has to go on in deciding between
empirical equivalent theories.

>>(1) Indistinguishable brains give rise to indistinguishable states
>>of consciousness.
>>
>>(2) Our reports of our conscious states, by and large, accurately
>>reflect those states.
>>
>>(3) Our memories of conscious experiences aren't radically mistaken,
>>by and large.

>Without assuming something like (2) and (3), we have nothing to go on
>in discussions of consciousness. However, I don't see the necessity of
>assuming (1). Why should it be that physical states "give rise" to
>unique mental states? An alternative point of view is that, rather
>than there being a function from mental states to physical states,
>there is simply a relation: This physical state is compatible with
>(rather than "gives rise to") that mental state. Compatibility would
>in general be a many-to-many relation.

Well, I'm happy enough calling it a mere "relation", but I find the
denial of supervenence implausible.  Given a mental state that
stands in that relation to my brain, it seems to me to be extremely
plausible that given an indistinguishable brain, it will stand in
that relation to an indistinguishable mental state.  Nothing about
this says the relation can't be many-to-many.  Indeed, given my views
about information, there are plenty of other "consciousnesses" that
stand in that relation to our brain, or at least to subsystems of
the brain (depending on whether we individuate the brain as an
object or as a system).

>In Searle's Response to the Systems Reply to the Chinese Room
>Argument, Searle suggests that you might memorize the rules for
>producing output based on inputs in Chinese. Regardless of whether
>this is a practical possibility, it is logically possible (as is the
>giant lookup table). According to one story, there are no thoughts
>other than your thoughts as you try to follow a set of mystifying
>rules that you have memorized. According to another story, your
>actions give rise to a Chinese mind which thinks thoughts that are
>expressed in Chinese.
>
>I believe that both stories are compatible with the physical facts,
>and that is the most that can be said. Contrary to how it might seem
>at first, this doesn't contradict principle of plausibilty (2), that
>our reports of our conscious states are reliable. Using introspection,
>you find that there is a definite fact of the matter about what you
>are thinking about; either you are thinking about your home in
>Beijing, or you are not. However, you cannot transfer this
>definiteness of thoughts to the physical object, your body, unless you
>identify your mind with your body. Given a mind, there may be a fact
>of the matter about what it is thinking about, but given a physical
>object, there might not be a (unique) fact of the matter about which
>mind it possesses.

Right, I agree that both of these are compatible with the physical
facts (that's more or less an admission of dualism).  I'm not sure
if this is the most that can be said -- I  think that there are
plausibility considerations, such as the "fading qualia" argument,
that militate in favour of the hypothesis that there are extra
thoughts there.  As for the last sentence, I don't think minds should
be associated with objects, but with systems.  Obviously there can be
many systems associated with a given object, and indeed the "object/
system" mapping may be somewhat vague, due to objects having vague
boundaries and the like.  But I do think there's a fact of the matter
about whether a given system has certain associated conscious states,
or not.  (I suppose one can also "test" for whether an object has
associated conscious states, by seeing which conscious states are
replicated when the object is replicated.  Presumably there may
be lots of these.  Of course this isn't a "test" in the usual sense
of the word, more of a definition of "associated conscious states".)

-- 
Dave Chalmers                            (dave@cogsci.indiana.edu)      
Center for Research on Concepts and Cognition, Indiana University.
"It is not the least charm of a theory that it is refutable."