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From: markrose@spss.com (Mark Rosenfelder)
Subject: Re: Minsky's new article
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References: <19941109.145452.394@almaden.ibm.com>
Date: Fri, 11 Nov 1994 19:40:55 GMT
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In article <19941109.145452.394@almaden.ibm.com>,
 <mpriestley@VNET.IBM.COM> wrote:
>Take this sentence: "The yellow pear sat in its own yellow reflection
>on the polished table top".
>
>Now, wherever the word "yellow" appears, replace it with a description
>of the neurological events that cause (or, in your world, are) yellowness.
>
>Aside from getting a much more unwieldy sentence, we have changed its
>meaning.  "Yellow pear" evokes a mental image of yellowness (and presumably
>its corresponding neurological events).  "<Description of neurological events>"
>evokes a mental image of sparking bits of grey matter (the evocation will
>obviously vary depending on your familiarity with the terms used).
>
>The two mental images are different.  If the neurological event and its
>product were truly identical, wouldn't the mental images they evoke be the
>same?  The fact that they aren't suggest to me that they are actually
>referring to different things.  Now, you might argue that they are referring
>to different aspects of the _same_ thing, but I might reply that they are
>indeed _different_ aspects, and that I consider at least _my_ aspect to be
>a thing in its own right.

This is not a very convincing test.  You can make sentences sound strange
by all sorts of transformations; it's just an exercise in style rather 
than a method of ontological investigation.

But there's a deeper problem; your test fails for all cases of reduction,
not just problematic ones.  Consider the reduction of thermodynamics to 
the statistical mechanics of molecules, surely the most successful of
reductions, and one where advocates of separate substance (e.g. phlogiston)
are few and far between.  Take the sentence "The meat on the fire is hot",
and replace "hot" with some sort of description of molecular events,
beginning perhaps "Trillions of agitated air molecules rain down on
the molecules comprising a portion of meat...."   We've "changed the meaning" 
in just the same sort of way as your example does, even though in terms of 
physical theory the two descriptions are completely equivalent.

(I am not talking about the qualia of hotness here, just temperature;
it may be clearer if you start with the sentence "The meat on the fire is
254 degrees Fahrenheit" instead.)

So the fact that a description of neurological events *sounds* different
than the word "yellow" does not at all show that neurology cannot explain
qualia.  *Any* scientific explanation sounds different than a simple
descriptive English sentence.
