From:	SMTP%"ghrosenb@phil.indiana.edu"  8-MAR-1996 08:51:21.49
To:	STAPP
CC:	
Subj:	Re: Reply to Hayes 5

From: "Gregg Rosenberg" <ghrosenb@phil.indiana.edu>
Subject: Re: Reply to Hayes 5
To: phayes@cs.uiuc.edu (Pat Hayes)
Date: Fri, 8 Mar 1996 11:48:51 -0500 (EST)
Cc: STAPP@theorm.lbl.gov, klein@adage.berkeley.edu, phayes@cs.uiuc.edu,
        A.Sloman@cs.bham.ac.uk, keith@imprint.co.uk, mckee@neosoft.com,
        brings@rpi.edu, patrickw@cs.monash.edu.au
In-Reply-To: <199603080745.BAA11230@tubman.ai.uiuc.edu> from "Pat Hayes" at Mar 8, 96 01:45:52 am
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Well, I'm stuck in town for another day because of the bad weather, so
I might as well respond! ;-)

> (exists x)( P=p(x)  and F=f(x) )
> My original 'identity' claim is here expressed by the single variable
> occurring in both functional arguments: contrast this with
> (exist x,y)( P=p(x)  and F=f(y) and x=/=y )

I'm glad you did this Pat. I was thinking yesterday, while eating a
chicken sandwich at Wendy's, that I was going to do the same thing to
try to communicate with you the difference in our positions. As far
as I can tell, everyone on this thread agrees with the first
formula you have above. There is one x, and both P(x) and F(x).

So far, So good. The *further* question we don't agree on is what *is*
this x. In particular, is this merely a functional thing (as you seem
to claim above). That is, we disagree on the higher-order claim:

(exists x) (All P) (P(x) -> (exists F) (F(x) and F = P))

To be absolutely clear: 
F = the functional facts
P = the phenomenal facts

A fact is the instantiation of a property.

A property can be understood loosely as whatever corresponds to a monadic
predicate or a relation in FOL or higher.

It seems to me the ES=MS example has actually led to a misunderstanding
based on the fact that ES and MS are *names* of an object, and they
happen to name the same object. Therefore, it is OK to say ES=MS in
ordinary language. This makes their use different than fact statements,
and questions about the identity of facts. I'll have to take credit for
some of the confusion, as I have been using them for an example based
on the idea that each name in fact has a different conceptual sense. The 
question of how we can move from two names with different conceptual
senses to a statement that they identify the same thing is entirely
equivalent to the question of how we can move from two facts (or sets
of facts) with different conceptual senses to a statement that they 
express the same fact. Notice, one way to handle MS and ES in FOL is:

(exists x) MS(x) and ES(x)

Given the the treatment of the names as expressing properties (i.e. aspects)
of x, we can ask the higher-order question: MS = ES (note, this is a 
*different* question than if they denote the same object). The answer seems
to be 'no.' (because the names have different conceptual content).

The issue *then* becomes, given the different conceptual content of MS
and ES, how can they be denoting the same thing? *That's* the place
where the story about entailment comes in: that facts about Venus entail
all the facts about MS (i.e. the facts we know about MS in virtue of its
being known to us as MS), and therefore 'Venus' denotes the same thing as 
'MS'; they also entail all the facts about ES, and therefore 'Venus'
denotes the same thing as 'ES'. By transitivity of identity, 'ES' denotes
the same thing as 'MS', expressed in ordinary langauge as ES=MS.

The analogous structure to the problem in the F and P case is to wonder
whether the F facts denote the same properties as the P facts. In particular,
a functionalist maintains that it is the F facts which exhaust the nature
of the mental kind. To establish this, it must be shown that the F facts
entail the P facts. (just as the facts about Venus entailed the facts
about MS and ES). The dualist argues this entailment fails, thus the
F facts are not the same facts as the P facts, thus the functional properties
are not the same properties as the phenomenal properties, thus they 
are two different aspects of the system, thus we need to find a deeper
characterization of the system which entails both the F facts and the
P facts. That is a dual-aspect theory.
 
Has the formalization helped? The tricky thing to get used to is the
idea that meaning *does* make a difference to ontology. One cannot
go around brutely asserting identities and so forth without exhibiting
the proper entailments.

> Yes, I had thought that is how we had been using the P/F abbreviation.
> Descriptions refer to the things they describe: surely this is the way that
> language is normally used?  For the record, I still have no idea what an
> 'ontological aspect' is.

Descriptions refer to things they describe, but they do so VIA an
aspect. For instance, both the following refer to Aristotle:

1) The teacher of Alexander the Great
2) The most famous student of Plato

But they contain *very* different information about him. This informational
difference corresponds to an ontological difference -- they describe 
different aspects of him. Ontologically, being the teacher of Alexander
the great is simply a different thing than being the most famous student
of Plato.

Same thing with the F facts and the P facts.

--Gregg


-- 
Honesty in academia
  _____  
 /     \
 |      |                             Gregg Rosenberg
 | --)(--                             
 C      _)  D'ohh!                    Will philosophize for food.
 |   ___\    /                        
 |  /  __)
 /_ \__/
/  \  / \