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From: kp@uts.amdahl.com (Ken Presting)
Newsgroups: comp.ai,sci.philosophy.tech
Subject: Re: Chess, Reductionism, Probablistic Determinism.
Summary: Forget about Reductionism - Implementationism works better
Keywords: reductionism, emergence, implementation
Message-ID: <ddbx02xv92LK01@amdahl.uts.amdahl.com>
Date: 17 Mar 90 00:42:24 GMT
References: <491fffd5.1a4d7@cicada.engin.umich.edu> <2080@aipna.ed.ac.uk> <492e6ff2.1a4d7@cicada.engin.umich.edu> <f8LD02XT91SS01@amdahl.uts.amdahl.com> <49331604.1285f@maize.engin.umich.edu>
Reply-To: kp@amdahl.uts.amdahl.com (Ken Presting)
Followup-To: sci.philosophy.tech
Organization: Amdahl Corporation, Sunnyvale CA
Lines: 127

In article <49331604.1285f@maize.engin.umich.edu> zarnuk@caen.UUCP (Paul Steven Mccarthy) writes:
>
>>>>(Chris Malcolm) asks: [...How is {some property of chess} the 
>>>> consequence of the laws of physics?...]
>
>>>(Paul Steven Mccarthy) answered: [...reductionism...]
>>>     The given property is a consequence of the rules of the game.
>>>     The rules of the game are the consequence of human perceptions
>>>         of pleasure. [pleasure <-- nuero-chemistry <-- chemistry
>>>                       <-- physics]
>
>>(Ken Presting) objects: [...]
>>It may be easy to write off chess as defined only for human pleasure,
>>but but such a move is not so easy for the rules of arithmetic, the
>>rules of logic, or the rules of a Turing machine.  [...]
>
>It occurred to me afterwards that the real crux of my beliefs stems
>from probablistic determinism.  You set up the dominoes 'just right'
>at the beginning, introduce a convenient cosmic big bang, wait a
>few eons, ... and voila!  Here we are, with this particular world,
>and all of its interesting properties.. . .
>It is a belief in "cause and effect", where the underlying "causal force"
>is the laws of physics -- just "the way the universe works".

What you have here is not so much an argument for reductionism, but
rather an argument against *emergence*.  By assuming that the starting
state has certain potential for making certain things happen later on,
you are saying that the ultimate effects were there, in some sense,
right from the start.  By bringing in the probabilistic type of
causality, you can say that chess was still a consequence of the initial
state, even though it was not certain to appear.  But this is not a
reduction of the rules of chess to the laws of physics.

I just happen to have another concept in my little catalog, which does
a much better job than "reductionism".  I call it "implementationism".
To give an example, let's switch from chess to algorithms:

When a computer calculates a function, its operation is entirely
controlled by the laws of physics.  But an algorithm cannot be reduced
to the operations of any one computer, or any one kind of computer, or
to computers at all.  Any physical operations which have the "right"
structure could be an instance of computing a function by the algorithm.
The "right" structure is not definable in terms of the laws of physics,
but *is* definable in terms of the logical structure of the algorithm.
There is a large class of physical objects which *could* be used as
automatic computers, and they all have such physical properties as allow
a homomorphism from the logical description of the algorithm's operation
to the causal description of the machine's operation.  (This is a case
of the "homomorphism of logical structure" I mentioned earlier this week).

This idea of implementing an abstraction in a physical device with a
"matching" logical structure is easily extended to sciences.  Chemistry
includes a very complex bunch of abstractions and general laws, which
most people think of as reducible to physics.  But - this is big - if
the physicists decide that say, Rutherford atoms are out, and Bohr atoms
are in, the chemists do NOT have to re-write the Periodic Table.  They
may perhaps change some of their plans and expectations for new
research.  The concepts of chemistry do not disappear into physics, and
I would even say that the concepts of chemistry do not change *meaning*
when physics changes.  Chemists' beliefs about the *reference* of their
terms changes, but that's about it.  That's because the relation between
chemical and physical theory is a like an implementation of a program.
If the implementation changes, most of the "high-level" functions are
unaffected.

Chess, mathematics, and logic now fit into the scheme with a lot less
mangling.  We know how to implement machines that can behave according
to any rules anyone would care to state.  And we ourselves know how to
follow rules.  What we don't know is how to implement a machine that
can learn all the rules human beings can learn, or even how much of
human behavior is based on rules and how much is based on causes.

But the general thesis of implementationism is: Everything is implemented
in Physics.  If implementationism is true, then we have a shot at re-
implementing intelligence in silicon.  We don't need Reductionism.

(Jerry Fodor has a great discussion of reduction in the first chapter of
 _The_Language_of_Thought_.  He makes a very good case against reducing
 psychology to physics, but I think Implementationism is much more elegant
 than his "Token Physicalism".  I could use a better name, though. :-)

> . . .   I _believe_ that the body of reasoning
>tools developed by humans are valid for describing the properties
>of the universe.  I also believe that this belief is a consequence of
>"the way that the universe works" (nice and recursive, isn't it?! :-).  

Statements such as this bring up an important point.  One part of being
an intelligent person is to recognize that one's beliefs come about in
a variety of ways.  Sometimes our beliefs seem to be "built in", and
sometimes our beliefs are deliberately adopted.  It is certainly foolish
to insist that all beliefs must have a justification, but on the other
hand, it would be disingenuous to hold any particular belief exempt
from all challenges.  Even the laws of arithmetic and logic can be
held up for scrutiny.  The intuitionists and constructivists may well
be wrong about doubting the law of excluded middle, but they are not
stupid or foolish to do so.

I would say that an AI which could not participate in a discussion of
the foundation of its beliefs was lacking in an important area of
human behavior.  I might go so far as to say that if a machine did
not make little jokes when it reveals the circularity of its reasoning,
it would lack another important human trait! (:-)

(Circularity in the foundations of reasoning is *very* difficult to
 avoid.  Even Kant could not avoid it.  He did not make many jokes,
 however...)

>Now, Ken, don't you agree that this kind of discussion really belongs
>in "philosophy somewhere..."?

I don't know.  I guess that "net protocol" requires extended discussions
to be conducted in talk.* groups.  I figure that as long as my articles
receive thoughtful replies here, I might as well continue to post here.
The value I derive from the ideas of the rest of the group is tremendous.

My impression is that the success of AI will probably entail the answers
to a bunch of philosophical questions.  I *love* answers, so I'm very
interested in the success of AI.

I have cross-posted and suggested followups to sci.philosophy.tech.

>Your awe-struck, but uncomprehending fan,
>---Paul...

Oops.  I'll try to be more comprehensible and less awful.  (:-)

Ken Presting