Path: utzoo!attcan!uunet!lll-winken!ames!ucsd!nosc!humu!uhccux!lee
From: lee@uhccux.uhcc.hawaii.edu (Greg Lee)
Newsgroups: comp.ai
Subject: Re: A Definition of "Symbol," "Symbolic," and "Symbol-Manipulation"
Message-ID: <3494@uhccux.uhcc.hawaii.edu>
Date: 16 Mar 89 13:01:37 GMT
References: <2308@tank.uchicago.edu>
Organization: University of Hawaii
Lines: 32

From article <2308@tank.uchicago.edu>, by staff_bob@gsbacd.uchicago.edu:
# >In the case of the latter, a logical semantics (e.g. the truth
# >table characterization of sentence logic) cannot have symbols,
# >by this account.
# > 
# As usual, you've gotten me a little confused. I thought that Harnad 
# gave a list of criteria for any logical formalism, in an effort to explain
# that by 'symbolic' we mean 'capable of being processed within the context
# of a formal system'.

'Formal' doesn't mean non-semantic.  There's something wrong with a
"list of criteria for any logical formalism" that excludes formal
logical semantics, don't you think?

Consider the demonstration of a theorem of sentence logic that uses
truth-table analysis.  It's formal, since it begins from the form of
expression of the theorem.  It's semantic because it considers the
possible denotations of the sentence variables.

# >Does this definition help clarify whether brain-events evoked
# >by or associated with perception, or evoked in other ways,
# >can properly be called symbols?  I don't see that it does.
# ...
# I don't think that's the point. The question is whether or not human
# thought can be characterized by a symbolic system, not whether or
# not it is one. ...

Well, if it is one, it can be characterized by one.  So maybe there
some relevance to the Searle experiment.  At any rate, I thought
this other point was also under discussion.

		Greg, lee@uhccux.uhcc.hawaii.edu