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Article 5765 of comp.ai.philosophy:
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>From: learn@speedy.acns.nwu.edu (William J. Vajk)
Subject: Re: Grounding: Real vs. Virtual (formerly "on meaning")
Message-ID: <1992May20.043004.2732@news.acns.nwu.edu>
Keywords: symbol, analog, Turing Test, robotics
Sender: usenet@news.acns.nwu.edu (Usenet on news.acns)
Organization: Dares No Organization Like Dis Organization
References: <1992May19.003821.9450@Princeton.EDU> <1992May19.220141.29649@psych.toronto.edu>
Date: Wed, 20 May 1992 04:30:04 GMT
Lines: 60

In article <1992May19.220141.29649@psych.toronto.edu> Michael Gemar writes:

>In article <1992May19.003821.9450@Princeton.EDU> Stevan Harnad writes:

>>In article <1992May18.200313.23575@psych.toronto.edu> Michael Gemar writes:

>>>Yet, such a simulated world, even if it was simulated down to the 
>>>atomic structure, would still, at least, as I understand your position 
>>>(and those others who demand "real world" grounding) be insufficient
>>>to attach semantics onto the symbols being manipulated.   This would be 
>>>true *even if a human would not be able to distinguish the artificial 
>>>world from the real one.* 

>>Computational equivalence is not the same as identity.

>Agreed.

Agreed in that this seems to be a religious issue of the first order.

>>The world of objects is analog; substantial parts of the nervous
>>system (and its tranducers/effectors necessarily) are analog.

By definition only. In reality I believe you can discover significant
binary aspects everywhere in the human body.

>You seem to place great weight on the analog nature of the physical
>world; indeed, it seems as though it is this aspect upon which
>you rest symbol grounding.

>Atoms are certainly discrete particles, and I believe that some 
>physicists have theorized that space and time may be discrete.

This has become a matter of routine demonstration for almost every 
experiment conducted in recent years. The general perception of
an analog nature remains unchanged.

>It is possible to imagine a world in which nature at its most 
>fundamental *isn't* analog (it may very well be this world), and yet 
>the beings in it still possess semantics.  

Most likely the reality.

>5. Statements 3. and 4. taken together seem to indicate that there
>   is a principled difference in the way that humans and programs could
>   obtain semantics.  Specifically, it points to a situation in which
>   what is sufficient for humans is not sufficient for a program.  The
>   grounding of symbols in the physical world, while not sufficient
>   for a program, is sufficient for a human.  Therefore, symbol
>   grounding in the physical world cannot be the cause of the     
>   meaningfulness of symbols. 

You seem to have developed a closed system here in which the key of 
equivalence isn't. The definition of equivalence, after all, is 
similarity of response to a given stimulus. It seems to me as though
you've just said, "1 != 1". I don't believe the problem is one in
which grounding isn't the key so much as the failure to accurately
replicate.

Bill Vajk



