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From: roelw@cs.vu.nl
Newsgroups: comp.ai
Subject: Chinese Room argument
Message-ID: <2125@star.cs.vu.nl>
Date: 6 Mar 89 11:23:35 GMT
Sender: roelw@cs.vu.nl
Reply-To: roelw@cs.vu.nl ()
Organization: VU Informatica, Amsterdam
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In responds to my question how a computer can "know" the denotation (reference)
of a symbol, if it is possible for the programmers, users. etc. to change the
denotation without affecting the output of the computations, 
kck@g.gp.cs.cmu.edu (Karl Kluge) wrote:

> I can change the denotation of the symbol "symbol" in the above passage from
> "symbol" to "soup can". That wouldn't make the slightest difference in the
> process by which you generated the passage

True. My production of a piece of text is not affected by your changing the
denotation of the symbols occuring in it. However, this does *not* imply that I
process the text in the same way as a computer processes it.

> how did *you* ever come to "know" the denotations of words/symbols in your
> mind?

I don't know; we should turn to empirical research on development psychology to
get some answers. I get the impression that you make the following assumptions:
1. I have a mind.
2. There are symbols in my mind.
Assumption 1 is metaphysical (there is no conclusive empirical or logical proof
of it, yet we (at least I) strongly believe in this assumption). My question to
you is to state, independently of assumption 2, what you mean by "mind." Is it
a different thing from my body? Can one exist without the other?

Assumption 2 begs the question whether thought works by the manipulation of
symbols. If it does, then apparently a symbol-manipulation device can learn to
speak a natural language such as Chinese (or Dutch in my case). However, the
truth of this hypotheses has not been shown empirically and Searle's argument
is designed to show its implausibility by a thought experiment. You shouldn't
assume the truth of 2 in criticizing Searle's experiment.

> In general, it only makes sense to talk about the programmer "changing the
> denotation of a symbol in a program" when that change produces corresponding
> changes it the program's output behavior, i.e. "changing the denotation of
> symbol 'xyz' from 'hide behind the nearest rock' to 'cover yourself with
> barbacue sauce and jump up and down and yell'" only makes sense if the
> generation of the symbol "xyz" in the program produces the corresponding
> difference in behavior. 

No. Read any textbook on formal languages or logic and you will find a clean
separation between the syntax and semantics of a language. Whether we can make
sense of the output of a symbol-manipulation process is completely irrelevant
to the rules of symbol-manipulation.

Also, note that I used the word "denotation" (synonymous with "reference") and
not "connotation" (synonymous with "sense"). The formal semantics of
connotation is much more difficult than that of denotation, and I think we can
argue about Searle's experiment using the first concept alone.

lee@uhccux.uhcc.hawaii.edu (Greg Lee) agrees with Karl. But then he writes in
<3388@uhccux.uhcc.hawaii.edu>:

> couldn't we reach the conclusion more immediately by
> considering the outcome to be given in terms of the denotations of any
> symbols it contains.  Then it is not, in general, invariant.

The output of a symbol-manipulation process is a string of symbols. Let's call
this O. The denotation of the string is given by 1. the denotation of the 
symbols in it and 2. rules for constructing the denotation of a well-formed 
string from those of its components. Let's call these rules D. Your proposal
is to call the pair (O, D) the outcome of the process. Obviously, this is not
indendent of D. However, O *is* indendent from D; it depends only on 1. the
string of input symbols 2. the rules for manipulating those symbols, and these
in turn are independent from D.

mike@arizona.edu (Mike Coffin) writes in <2121@star.cs.vu.nl>:
> What makes you think that a program sophisticated enough to answer
> questions in Chinese is going to represent a chair or a table as a
> single symbol?  

Well, nothing makes me think that. I wrote:

 "The denotation of the symbols, and of expressions built from these symbols,
  is not relevant for the outcome of the TM computation."

Exressions are built from symbols according to the rules for well-formed
expressions of a language. If you wish, replace "expressions" by "formulas."
These could be even higher-order formulas, but I assume for the moment that
they have a finite size (=number of symbols in them). 

Roel Wieringa
Dept. of Math. & Comp. Science
Vrije Universiteit
de Boelelaan 1081
1081 HV Amsterdam