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Article 4434 of comp.ai.philosophy:
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>From: orourke@unix1.cs.umass.edu (Joseph O'Rourke)
Newsgroups: comp.ai.philosophy
Subject: Re: The Systems Reply I
Message-ID: <44765@dime.cs.umass.edu>
Date: 12 Mar 92 16:20:21 GMT
Article-I.D.: dime.44765
References: <1992Mar6.185926.18497@oracorp.com> <1992Mar9.171606.6886@psych.toronto.edu> <6374@skye.ed.ac.uk> <1992Mar11.201637.21875@psych.toronto.edu>
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Reply-To: orourke@sophia.smith.edu (Joseph O'Rourke)
Organization: Smith College, Northampton, MA, US
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In article <1992Mar11.201637.21875@psych.toronto.edu> 
	christo@psych.toronto.edu (Christopher Green) writes:

  >In article <6374@skye.ed.ac.uk> 
  	jeff@aiai.ed.ac.uk (Jeff Dalton) writes:
  >
  >>BTW, I still haven't seen a satisfactory answer to the point that
  >>the Room manipulates meaningless symbols (ie, treats them syntactically)
  >>without any way to attach meaning to them.  But maybe I've just
  >>missed it in all the noise.
  >>

>Ah, once again I leap into the breach! Jeff, you're absolutely right. IF
>you're phraseology convinces the hordes that have been unconvinced by me,
>then terrific. It is very straightforward. The symbols (by definition!)
>have no meanings. 

	It seems to me that the way in which a program manipulates
its symbols shows that it has attached some type of meaning to them:

(a) As a crude example, if a program passes a double to a function to
    compute the arctangent, it "knows" in some primitive sense that
    the bits it is moving around represent a real number, and that
    the library arctangent function expects such.  The bits are not
    meaningless:  they are manipulated in a way appropriate for double-
    precision floating point numbers.
    
    Objection 1:  This is a very primitive sense of "meaning."
    Reply:  Agreed.  But perhaps "real" meaning can be built from zillions
    	of little bits of primitive meanings.
    
    Objection 2:  Regardless, whatever meaning is there is provided by
    	the author of the program, not the program itself.
    Reply:  See example (b).

(b) Consider Lenat's program AM.  It *creates* an operator, which we
    know as "divisors-of."  It was not given this operator by Lenat.
    It then experiments with this operator by applying it to various
    integers.  In some sense, it "knows" that the argument to divisors-of 
    must be an integer, and it manipulates its symbols in accordance 
    with this knowledge.  The program AM has attached meaning (albeit 
    primitive meaning) to some of its symbols.

I have never understood why everyone seems to believe that the symbols
manipulated by a running program have no meaning.  The very manipulations
performed by the program indicate that they have some meaning,
meaning *to* the program (as well as to us), and sometimes, meaning
assigned *by* the program.


