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From: kenp@ntpdvp1.UUCP (Ken Presting)
Newsgroups: comp.ai
Subject: Re: No more Chinese rooms, please?
Summary: What formula best represents Searle's conclusion?
Message-ID: <597@ntpdvp1.UUCP>
Date: 10 Jul 90 01:18:45 GMT
References: <25422@cs.yale.edu> <593@ntpdvp1.UUCP> <31329@cup.portal.com>
Organization: SNA Solutions Inc., Contract Programming Group
Lines: 111

> |> In article <593@ntpdvp1.UUCP> kenp@ntpdvp1.UUCP (Ken Presting) writes:
> |> |. . .     Searle is trying to prove the following:
> |> |
> |> |       For any program P whatsoever, and for any machine M whatsoever,
> |> |       the following inference is always invalid:
> |> |
> |> |       Machine M runs Program P, therefore Machine M understands.
>
> Tom Blenko writes: 
> This is much too strong, and you are arguing against yourself...
> . . .  
> It reads as
> 
>	 FORALL P FORALL M  NOT(M(P) ==> M understands)
> 
> which says that no program running on any machine  results in a machine
> that "understands".  . . . 

Tom, you are mistaken.  You have overlooked the distinction between 
"valid inferences" and conditional assertions.  In standard symbols,
my version of Searle's thesis would read:

	(P) (M) - ( M runs P |= M understands ) 

The "|=" symbol denotes the logical relation called "entailment".  The
simple conditional form which you use here ignores Searle's repeated
use of conjunctions like "must" and "simply by virtue of", which indicate
a *necessary* relation between the antecedent and consequent.  (I have
neglected the object- vs. meta-language issue in my formula, but that
should not lead to much confusion.  I have also avoided the standard modal 
interpretation of "necessity", which should positively reduce confusion.)

Since entailment is a stronger relation than implication, the negation
of an entailment is weaker than than a negation of an implication, and
my version of Searle's claim has similar truth conditions to the version
you propose below.  Since Searle is claiming (on my reading of him) that  
the running of any program will not *necessitate* the presence of 
understanding in any machine, he can proceed in two steps, the first of
which is identical to your proposal:

> . . . Searle's position 
> is closer to saying there is no universal intelligent program, i.e.,
> 
>	 NOT(EXISTS P FORALL M  M(P) ==> M(P) is intelligent)
> 
> which is logically equivalent to the much weaker (than yours) assertion
> 
>	 FORALL P EXISTS M  NOT(M(P) ==> M(P) is intelligent)
> 

Notice that for Searle to support this last claim, he needs to demonstrate
the existence of a single Machine such that no matter what Program it is
running, it will not understand Chinese.  He thinks he has done so with
the Chinese Room.  Perhaps he has not, but that is another question.  If
the CR example is successful, then he has his first step.

Perhaps the difference between your reading of Searle and mine comes to this: 
You have formulated the conditions which he tries to meet with the CR example
itself, while I am attempting to formulate the general conclusion for the 
argument of which the CR example is a part.

The second step requires the application of a rule of inference which is
analogous to "Universal Generalization" in natural deduction systems.  If 
Searle is granted the assumption that there is no relevant difference between 
the case of a computer running a program and himself running the same    
program, then he can conclude for all machines that there is no necessary
connection between the program it runs and its understanding.  Searle thinks
this assumption follows trivially from "Axiom 1: Programs are purely formal".
Pat Hayes denies the assumption (with some justice, I think, but the issue
is not simple).


> I say that you are arguing against yourself because you attribute this
> claim to Searle (and the informal one it is intended to capture, saying
> that Searle denies the "relevance" of programs), yet it is at odds with
> your acknowledgement that Searle is not arguing against the possibility
> of an intelligent, artificial entity.
> 

Even on your own formulation of my reading, this does not follow.  From

	(P)(M) - ( Runs(M,P) -> Understands(M) )

it does not follow that 

	(M) - ( Understands(M) ).

All that follows is that running a certain program is not a sufficient
condition for understanding.  

Now, you may object that if the question "What program is that machine
running?" is not enough to decide the issue of the machine's intelligence,
then no amount of additional information could ever establish that a
general-purpose computer is intelligent.  Many people do believe this
(the Churchlands seem to), and propose that Connectionism is the only 
hope of AI.  

Whatever the status of that issue, the Chinese Room does not, by itself,
establish that no programmed general purpose computer can understand.  If 
it establishes anything, it establishes *only* that we must know more 
about a computer than what program it is running, before we draw any 
conclusions about its intelligence. 

> Tom
> 

Thanks for your comments.  I especially appreciate the formal direction
you have given to this thread.  If we can keep this up, we may get 
somewhere.

Ken Presting  ("Metastasis Before Modality")