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From: tmoody@sjuvax.UUCP (T. Moody)
Newsgroups: net.philosophy
Subject: Re: Sc--nce Attack (self-awareness)
Message-ID: <2395@sjuvax.UUCP>
Date: Wed, 16-Oct-85 10:12:10 EDT
Article-I.D.: sjuvax.2395
Posted: Wed Oct 16 10:12:10 1985
Date-Received: Sat, 19-Oct-85 05:50:15 EDT
References: <45200016@hpfcms.UUCP> <1605@pyuxd.UUCP>
Reply-To: tmoody@sjuvax.UUCP (T. Moody)
Organization: St. Joseph's University, Phila. PA.
Lines: 61
Keywords: Turing machines vs. the mind
Summary: 

In article <10642@ucbvax.ARPA> tedrick@ucbernie.UUCP (Tom Tedrick) writes:
>
>OK, here is a question.
>
>My understanding is that Godel's incompleteness theorems prove
>(assuming the consistency of Arithmetic) that no Turing machine
>can possibly simulate the human mind.
>
>This is because for any particular Turing machine there are certain
>statements that the human mind can recognize as true (again with
>the consistency assumption), that the machine cannot recognize
>as true.
>
>Does anyone dispute this?
>
>   -Tom
>    tedrick@ucbernie.ARPA

[]
     As it turns out, almost *everybody* disputes this, these days.
The position that you mention was made famous by the English
philosopher J. R. Lucas  (I can't recall the name of the paper, but
I'll dig it up and post it if anybody's interested).  Goedel's first
incompleteness theorem states that in any formal system of arithmetic
there are true sentences that are not provable, *in that system*.
This does not entail that they are not provable in *some other* formal
system of arithmetic.  That means that even though Turing machine A
might not be able to "prove" (i.e., mechanically derive) true sentence
S, Turing machine B might be able to (but there will be sentences that
B cannot prove, etc.).

     So, minds might just be Turing machines instantiating *different*
formal systems.  Searle's objections to Turing machine functionalism
are utterly different from Lucas's.  Since Searle's work has been
cited several times by Michael Ellis and myself, I am working on a
succinct presentation of his arguments, which I will post soon.  For
those who have the time, just read Searle's paper "Minds, Brains, and
Programs."  Already a classic, it has been anthologized in Hofstadter
and Dennett's _The_Mind's_I_, and in John Haugeland's _Mind_Design_.
The original paper appeared in volume 3 (I forget which no.) of
_Behavioral_and_Brain_Sciences, along with about two dozen responses
from philosophers and AI people.

     Another excellent source for clean and cogent arguments that are
critical of Turing machine functionalism is Ned Block's "Troubles with
Functionalism" (Minnesota Studies in the Phil. of Science, vol. 9,
1978), anthologized in Block's
_Readings_in_the_Philosophy_of_Psychology_, vol. 1 (Harvard U. Press).
This is an excellent volume.  It also contains Thomas Nagel's "What Is
It Like To Be A Bat" (in Mind's I, too).

     For pro-functionalist arguments, the most readable source is
Dennett's _Brainstorms_.

     But enough is enough.


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."