From: chalmers@bronze.ucs.indiana.edu (David Chalmers)
Subject: Re: Dualism
Organization: Indiana University
Date: Sat, 12 Sep 1992 03:44:04 GMT

In article <18q0pbINNrcc@agate.berkeley.edu> epfaith@sunkist.berkeley.edu (Edward Paul Faith) writes:

>Until that moment of revelation, we might be touch/sight
>dualists.  We imagine that there are two ways of being real, a
>touch way and a sight way.  A thing can either be touched (or
>some touch physical apparatus can discover its existence and
>tell us via touch) or else it can be seen (or some sight
>apparatus can tell us via pictures that it exists in the sight
>world--let us not worry how we make these latter machines).
>We imagine that we are aware of two ways of being real.  We
>have no reason to suppose they share something in common.
>Logically, it is possible for the two kinds of existence to be
>separated.  But to someone with integrated sight and touch,
>such speculations are nonsense.  There are not two kinds of
>existence, but merely two kinds of perception!

That's true: touch/sight dualism would be an epistemic possibility
in this situation.  However -- and this is what's important --
once all the physical facts were in, we would have all the
information about the causal antecedents of our touch judgments,
and of all our sight judgments, and we'd know that they were the same
thing.  The epistemic possibility of such dualism only arises
because of our ignorance of those physical causal chains.  Relative
to the physical facts, touch/sight dualism is a non-starter.

But there doesn't seem to be any analogy with consciousness here.
Even once all the physical facts are in about how the brain
works, and introspects, and so on, it seems that it will still
be a  further fact about why it *feels* like this.  (In a
sense, the same holds for touch and sight: getting the physical
facts right will establish that the things that we're touching
and seeing are the same physical things, but the experience
of tactile and visual sensations will continue to be a mystery.)

>So here is my idea:  someday, when we are able to
>manipulate the brain however we like, our introspection will
>become integrated with our physical senses, and we will
>cease to think that the mind has a different sort of reality from
>the brain, and we will laugh at ourselves for having fretted so
>much about the mind/body dualism, when the only duality
>was one of unintegrated ways of perceiving.

I don't think of consciousness as going along with introspection,
particularly.  The problem arises just as strongly with our
sensations arising from perception of the outside world.  But
either way, for both sensations and introspective experiences,
regardless of the causal chains that form the bases for such
experiences, the question still arises: why are those causal
chains accompanied by conscious experiences?  The brain and
cognitive sciences can tell us a lot about the nature of those
causal chains, but they don't seem to tell as anything about
this further question.

-- 
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."