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Article 4832 of comp.ai.philosophy:
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>From: orourke@unix1.cs.umass.edu (Joseph O'Rourke)
Newsgroups: comp.ai.philosophy
Subject: Re: A rock implements every FSA
Summary: Realization requires causality
Message-ID: <45773@dime.cs.umass.edu>
Date: 31 Mar 92 02:56:47 GMT
References: <1992Mar30.150319.7149@oracorp.com>
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Reply-To: orourke@sophia.smith.edu (Joseph O'Rourke)
Organization: Smith College, Northampton, MA, US
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Although Putnam does not define the key concept of "realization,"
one can infer from his proof that causality is essential:

	if 	FSA-state A transits to FSA-state B
	then 	rock-state A must cause rock-state B

This is what he proves on p.123 for an FSA with no input.
	Extrapolating from this, it would make sense to require
causality for realization of FSA's with input, along these lines:

	if 	FSA-state A, upon receiving FSA-input I, 
		transits to FSA-state B
	then 	rock-state A, in conjunction with rock-input I,
		must cause rock-state B

What I don't see in the proposals of Mikhail Zeleny and Daryl McCullough
is how to identify something physical that can correspond to rock-input I
so that the causality relation is maintained.  Without that, the rock
doesn't realize the FSA-with-input in Putnam's sense.  It does so in
some other sense of "realize," to me a less natural sense.



