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>From: chalmers@bronze.ucs.indiana.edu (David Chalmers)
Subject: Re: Causes and Reasons
Message-ID: <1991Dec24.020441.8340@bronze.ucs.indiana.edu>
Organization: Indiana University
References: <1991Dec23.041134.6879@husc3.harvard.edu> <1991Dec23.210052.25960@bronze.ucs.indiana.edu> <1991Dec23.185045.6898@husc3.harvard.edu>
Date: Tue, 24 Dec 91 02:04:41 GMT
Lines: 59

In article <1991Dec23.185045.6898@husc3.harvard.edu> zeleny@brauer.harvard.edu (Mikhail Zeleny) writes:

>>Your last post on the subject demonstrated a sufficiently gross
>>misunderstanding of the notions of supervenience and implementation
>>that there was little point in continuing the discussion.
>
>I see my use of the term `supervenience' as wholly consistent with its
>introduction in modern philosophical discourse by R.M.Hare, as well as its
>use in the philosophy of mind by Donald Davidson; should you care to
>substantiate your accusation, I would be happy to supply a more precise
>reference to the sorces.

Well, it's sometimes difficult to tell the difference between a gross 
misunderstanding of a term, and a correct understanding combined with
wildly fallacious inferences.  I therefore concede that it is possible
that you understand the meaning of "supervenience".  Either way,
your suggestion that lack of type-type nomological regularities implies
inability to circumscribe a supervenience base is just silly, as
evidenced by the simple case of supervenience of mental states on
brain states (there may be no type-type laws, but we can circumscribe
a supervenience base without problems; just take the entire brain).

>If you wish to restrict it i n the above way, that's fine, as long as you
>don't impute a nonexistent causal structure to a piece of paper with marks
>on it.

As I've said about a zillion times: programs don't have causal structure,
implementations of programs do.

>Once again, the rightness of your causal structure is determined by whoever
>determines the correctness of implementation.

This is just irrelevant.  The origin of the implementation relation doesn't
matter.  All that matters is that *if* the system is an implementation, then
it has the right causal structure.

>The implementation of a program in a physical system *depends* on the
>systematic semantic determination of the former, i.e. on the interpretation
>of the syntax of the language in which it is written; it also depends on
>the systematic pragmatic determination of the same, i.e. in relating its
>illocutionary structure (procedure calls) to the physical processes within
>the computer.  Both, taken together, constitute its implementation.  Both
>require conscious agency, per my argument elsewhere.

I'll resist the temptation to say much about the relation between semantics
of programming languages and semantics of logical systems (insofar as
there's an analogy to be made, it's between the stipulated semantics of a
programming language and the stipulated semantics of the logical operators,
not the semantics of terms), and even about the role of conscious agency
(if a twin of my Sun workstation miraculously formed from the dust, it
would still be implementing programs), as they're irrelevant to the main
point.  Which, as ever, is: *if* a system implements a given program, *then*
it has a certain causal structure.  That's a conditional.  How the
antecedent comes to be satisfied is no concern of mine.

-- 
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."


