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From: tmoody@sjuvax.UUCP (T. Moody)
Newsgroups: net.philosophy
Subject: Searle's Pearls
Message-ID: <2412@sjuvax.UUCP>
Date: Fri, 18-Oct-85 12:23:45 EDT
Article-I.D.: sjuvax.2412
Posted: Fri Oct 18 12:23:45 1985
Date-Received: Sun, 20-Oct-85 06:11:54 EDT
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Organization: St. Joseph's University, Phila. PA.
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[]
     Here is the promised summary of John Searle's much-discussed
"Minds, Brains, and Programs".  In this posting, I shall *just*
summarize, and withhold any comments that I might be tempted to make.

     Searle identifies what he calles a "strong AI" thesis: "The
appropriately programmed computer really *is* a mind, in the sense
that computers given the right programs can be literally said to
*understand* and have other cognitive states."  Strong AI, then, is a
thesis that belongs to the more general philosophy of mind called
"Turing machine functionalism" (so much for refraining from comment).

     Searle believes the strong AI thesis to be false.  His key
argument is the "Chinese Room" counterexample...

     Imagine yourself in a little room.  From a slot in one wall, you
receive sheets of paper, with various inscriptions on them.  On the
table before you is a *large* manual.  Depending on the precise
configuration of the inscription you have received, you refer to
various rules and tables in the manual.  Following the complex
instructions therein, you draw some marks on a blank page and, when
finished, pass it through a slot on the other wall.

     The manual is written in English, which you understand, but the
marks on the papers mean nothing to you.  They are just marks.

     What you don't know is that the papers which you are receiving
are Chinese texts, and the papers you are passing through the outbound
slot are also Chinese texts.  Furthermore, your output papers are
perfectly *appropriate* Chinese texts; they are natural responses to
the input texts (even though you don't know this).  In short, you are
passing the Turing Test in Chinese.

     But you still don't *understand* Chinese.  All you understand is
the fiendishly complicated manual in front of you.  Conclusion:
instantiating a Turing Machine algorithm -- which is what you've been
doing -- is not a sufficient condition for understanding a natural
language, so the strong AI thesis is false.  In Searle's words,
"whatever purely formal principles you put into the computer, they
will not be sufficient for understanding, since a human will be
able to follow the formal principles without understanding anything."

     Searle considers and responds to various objections.  I won't
rehearse that part of the paper here.  I will, however, point out that
Searle is not defending dualism.  He says, "My view is that *only*
a machine could think, and indeed only very special kinds of machines,
namely brains and machines that had the same causal powers as brains.
And that is the main reason strong AI has had little to tell us about
thinking, since it has nothing to tell us about machines.  By its own
definition, it is about programs, and programs are not machines."

     I hope that this clarifies things for those who were wondering
about the references to Searle that have been appearing in this
newsgroup.  (Hey, Searle is at Berkeley.  Why doesn't somebody at
ucbvax get him onto the net?)


Todd Moody                 |  {allegra|astrovax|bpa|burdvax}!sjuvax!tmoody
Philosophy Department      |
St. Joseph's U.            |         "I couldn't fail to
Philadelphia, PA   19131   |          disagree with you less."