Path: utzoo!utgpu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!ria!cs!wsaba
From: wsaba@cscs.uwindsor.ca (Walid Saba)
Newsgroups: comp.ai.philosophy
Subject: Re: AGAINST FORMALISM?
Summary: FORM in FORMAL means more than just the "form"
Message-ID: <558@schoenfinkel.cscs.uwindsor.ca>
Date: 23 Jun 91 17:13:22 GMT
References: <549@schoenfinkel.cscs.uwindsor.ca> <DIRISH.91Jun21074642@csc-sun.math.utah.edu>
Organization: School of Computer Science, Univ. of Windsor, Ontario, Canada
Lines: 53

In article <DIRISH.91Jun21074642@csc-sun.math.utah.edu>, dirish@csc-sun.math.utah.edu (Dudley Irish) writes:
> The problem in this discussion is that we keep runing together the
> notions of reasoning rationally and formal logic.  Remember the FORM
> in formal means that we operate only on the form of the expression,
> NOT on the meaning.  

But meanings (according to some theories) have a well defined "form", which
means that one could investigate a formal analysis of meanings. 
(the structure, or form, of meanings is, of course more complex, and to
this point no single view is full proof... ). For example, Carnap-Cresswell-Montague
like theories suggest that the srtructure of meanings is what is called *intensions*,
while Kaplan have a slightly different view (information contents), Barwise suggested
*situations*, etc...

>It is not clear to me how a formal system can
> have any meaning.  

In a way you are right. Everything is done by manipulating symbols, according to some
well defined set of rules. Which means, we are only doing syntax. 
If you mean that we don't know how meanings are represented 
in our minds, than of course you are right. However, we do know that we can associate
symbols, pictures, sounds, images, etc. with some "peice of information" that corresponds
to reality... This could serve as meaning, what do you think???

Now FORM in FORMAL does correspond to the well-formedness aspect of a language, ie to
form, (or structure), which is the syntax. However, languages have *semantics* and if
these are not *formal* than that is where the people who are AGAINST FORMALISM do not
see where the trouble lies.... Essentailly, one must justify his semantic theory, and
unless it is formal (sound!!!!) not much could be done, if anything at all ****** 

> This is a very complex issue and it is by no means
> well understood.  I am in no position to try to argue about languages
> of thought, rule based reasoning, or any of the other complex issues
> from philosophy of mind.  I just want to remind people that the
> usefulness of formal logic is that it does not depend on the meaning
> of the terms.  This in my opinion restricts its usefulness in
> explaining the meaning of thoughts.

I understand your point about logic being essentially a formal language for 
manipulating symbols, independent of what these symbols mean. Essentially what you are
saying is that EVERYTHING is syantx... This is an interesting argument, which I discussed
with lots of people before. But recall, that inference rules, and even axioms in logic
are usually justified semantically, ie they do correspond to some view...
Of course, once these have been accepted, than all we need to do afterwards is syntactic
manipulation, without any semantics. But recall, even a simple rule as (A or ~A), is considered
to be true in all contexts, since we have a *semantic* justification for it. It is
intuitively justified... etc. Is that true or not???? 

WALID SABA	wsaba@cs.uwindsor.ca
		University of Windsor
		School of Computer Science
		Windsor, Ontario, Canada N9E 1X3
		(519) 253-4232 Ext. 3003/3005