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Re: Comment on "Meaning and the Semantic Web"

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Thu, 06 May 2004 08:27:03 -0400 (EDT)
Message-Id: <20040506.082703.88178821.pfps@research.bell-labs.com>
To: JohnBlack@deltek.com
Cc: public-sw-meaning@w3.org

Dan Brickley made what I think is an excellent response to this question,
but I'll provide a response as well.

From: "John Black" <JohnBlack@deltek.com>
Subject: Comment on "Meaning and the Semantic Web"
Date: Tue, 4 May 2004 21:31:17 -0400

> 
> Bijan, Peter,
> 
> In your poster paper, "Meaning and the Semantic Web",
>  http://www-db.research.bell-labs.com/user/pfps/publications/meaning.pdf,
>  you make the following statement:
> 
> "One might think that our account of meaning thus results in complete
> anarchy in the Semantic Web. Even if so, we believe we have
> embraced only those portions of anarchy that are necessary to prevent
> totalitarianism, for any proposal for Semantic Web meaning
> that cuts off easy access to disagreements will inevitably end up
> stultifying the Semantic Web."
> 
> I am finding this reference to totalitarianism hard to accept.
> 
> In the first place, if you mean it literally, and a typical definition 
> of totalitarianism reads like this, "Of, relating to, being, or imposing 
> a form of government in which the political authority exercises absolute 
> and centralized control over all aspects of life, the individual is 
> subordinated to the state, and opposing political and cultural 
> expression is suppressed: "A totalitarian regime crushes all autonomous 
> institutions in its drive to seize the human soul" (Arthur M. 
> Schlesinger, Jr.)." 
> http://dictionary.reference.com/search?q=totalitarianism
> Please explain how any of the proposals that have been discussed 
> could lead to this?

Under a scheme where the owner of a URI reference (ruler of a state) has
absolute control over the meaning of the URI reference, it is the case that
if one wants to communicate using a particular URI reference (live in a
particular state) then one must completely subjugate one's own view of the
meaning of the URI reference (one's own thoughts) to that of the owner of
the URI reference (ruler of the state).  One can, indeed, not use a
particular URI reference (leave the state) but then one really cannot
communicate with other users of that URI reference (inhabitants of the
state).  So, yes, opposing expression (including all forms of expression,
not just political and cultural express) is indeed suppressed, and this
does lead to a very large degree of control.

I would even go further in the analogy.  One often wants to use URI
references from multiple owners, so one would be subject to multiple
controls on one's expression.  These controls could (and, I think, would
often) become mutually incompatable, leading to collapses of communication.

> In the second place, hoping that you mean this loosely and 
> metaphorically, even given one of the many proposals for fixing 
> the meaning of URIs, assuming they could work, what would prevent 
> you from creating an entirely new set of URIs with which to use to 
> make whatever contrary statements you desired?  

Nothing whatsoever.  So what?  If I *choose* to be contrary in this way
then no one will talk to me, because I will be using my own private
language.  This really only hurts myself.

> Why is it *necessary* 
> for you to use anyone else's URIs at all?  

Because without any common terms, there is absolutely no possibility of
communication.

> If you are free to 
> create any URIs you may possibly need, with whatever meaning you may 
> wish to associate with them, in order to state whatever it is you want 
> to state, how can you then say that another set of URIs forms a 
> totalitarianism?  

Because to communicate, you have to share terms.  These terms become a
shared communication resource that should not be totally subject to the
arbitrary whims of the ``owner'' of the term.  

Consider a different analogy, related to the English language.  Suppose
that the meanings of English words that start with each particular Latin
letter are mandated to be those that are found in some particular on-line
dictionary.  I maintain that the owners of each of these dictionaries would
then have incredible power.  Sure, I could remove myself from the control
of a particular dictionary owner by refraining from using words whose
definition depends on that dictionary, but I would then, in essence have to
invent an entirely new language (and one using non-Latin characters).  But
then who would I be able to talk to?

> For I have never seen any proposal that requires 
> that there be only one URI for any referent, but only proposals that 
> any URI have only one referent.  So there can be many URIs for any
> referent.  So if you want to dissent, you can always create a new URI.

Sure, but how will I be able to communicate that my URI reference has the
same referent as the customary one?  Remember, if I use the customary URI
reference, I have to then abide by all the meaning ascribed to it by its
owner. 

> The model theory seems to allow for this:
> "There are several aspects of meaning in RDF which are ignored by this 
> semantics; in particular, it treats URI references as simple names, 
> ignoring aspects of meaning encoded in particular URI forms [RFC 2396]..."
> http://www.w3.org/TR/rdf-mt/  

This has no bearing on the issue under discussion.  

> Thus you can create any *possible web* you 
> want, in order to say anything you want, and this would be true even if 
> all *actual web* URIs were somehow given fixed meanings, wouldn't it?

Yes, sure, but, as above, I then loose the ability to communicate.

> This hardly seems a prescription for totalitarianism.  

Well, yes, I will give you that totalitarianism only comes out if you want
to communicate with others.  Perhaps the paper should have included that as
a premise.  :-)

> John Black
> Senior Software Architect,
> Time & Expense Collection Group,
> Enterprise Systems Division,
> Deltek Systems, Inc. www.deltek.com
> Office: 703-885-9656
> Mobile: 434-825-3765
> JohnBlack@deltek.com

Peter F. Patel-Schneider
Bell Labs Research
Received on Thursday, 6 May 2004 08:26:47 GMT

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