Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!udel!princeton!phoenix!harnad
From: harnad@phoenix.Princeton.EDU (Stevan Harnad)
Newsgroups: comp.ai
Subject: Re: What is a Symbol System?
Summary: Explicit Rules Are Needed for Systematic Interpretability
Keywords: computation, symbol manipulation, syntax, formality
Message-ID: <12195@phoenix.Princeton.EDU>
Date: 14 Dec 89 06:51:47 GMT
References: <11640@phoenix.Princeton.EDU> <17189@netnews.upenn.edu> <21032@unix.cis.pitt.edu>
Organization: Princeton University, NJ
Lines: 27



anwst@unix.cis.pitt.edu (Anders N. Weinstein)
of Univ. of Pittsburgh, Comp & Info Services wrote:

> "Explicit representation of the rules" is a big red herring...
> nothing requires a symbol system to be "rule-explicit" (governed by
> representations of the rules) rather than merely "rule-implicit"
> (operating in accordance with the rules). The important thing is simply
> that a symbol system operates by manipulating symbolic representations,
> as you've characterized them... if you're clever enough, you can
> probably interpret any symbol system either way

I'm not convinced. Whether a rule is explicit or implicit is not just a
matter of interpretation, because only explicit rules are
systematically decomposable. And to sustain a coherent
interpretation, this decomposability must systematically mirror every
semantic distinction that can be made in interpreting the system. Now
it may be that not all features of a symbol system need to be
semantically interpretable, but that's a different matter, since
semantic interpretability (and its grounding) is what's at issue here. I
suspect that the role of such implicit, uninterpretable "rules" would
be just implementational.
-- 
Stevan Harnad  Department of Psychology  Princeton University
harnad@confidence.princeton.edu       srh@flash.bellcore.com
harnad@elbereth.rutgers.edu    harnad@pucc.bitnet    (609)-921-7771