W3C home > Mailing lists > Public > www-tag@w3.org > February 2008

RE: New version of URI Declarations

From: Pat Hayes <phayes@ihmc.us>
Date: Fri, 29 Feb 2008 09:10:14 -0600
Message-Id: <p06230901c3edd0472258@[]>
To: "Booth, David (HP Software - Boston)" <dbooth@hp.com>
Cc: "www-tag@w3.org" <www-tag@w3.org>

At 2:23 AM +0000 2/29/08, Booth, David (HP Software - Boston) wrote:
>Hi Pat,
>I think I see your point: without me standing in front of you, 
>pointing to the moon and saying: "I hereby declare that 
>http://dbooth.org/2007/moon/ henceforth refers to *that* moon", my 
>URI declaration cannot be guaranteed to be understood as referring 
>to the actual moon.
>That sounds like a valid point, but it doesn't invalidate the notion 
>of a URI declaration.

It does invalidate what you say about it, however. And I wonder quite 
what is the point of it, if it can't do what you say it is intended 
to do.

>Mechanically, a URI declaration really only creates an association 
>between a URI and a set of assertions (the "core assertions").

Well, OK, but now I would ask, why do we need anything special to do 
this? Publishing some OWL and giving the document a URI does this 
already. So whats so special about the new idea?

>The interpretation of those assertions as describing a particular 
>resource  -- whether you interpret them the same way I do -- is a 
>different issue.  That problem exists regardless of whether one 
>accepts the notion of URI declaration.  URI declarations do not try 
>to solve that problem.

So, what problem DO they solve?


>David Booth, Ph.D.
>HP Software
>+1 617 629 8881 office  |  dbooth@hp.com
>Opinions expressed herein are those of the author and do not 
>represent the official views of HP unless explicitly stated 
>>  -----Original Message-----
>>  From: Pat Hayes [mailto:phayes@ihmc.us]
>>  Sent: Thursday, February 28, 2008 2:56 PM
>>  To: Booth, David (HP Software - Boston)
>>  Cc: www-tag@w3.org
>>  Subject: Re: New version of URI Declarations
>>  At 10:18 PM +0000 2/27/08, Booth, David (HP Software - Boston) wrote:
>>        I've substantially revised and expanded my write-up on
>>  URI declarations:
>>        http://dbooth.org/2007/uri-decl/
>>        For anyone interested in issues of resource identity
>>  and proper use of URIs, I strongly recommend reading it.  If
>>  you already read an earlier version, this version has added
>>  sections on granularity, ancillary assertions, why it's
>>  important to distinguish URI declarations from ancillary
>>  assertions, and an explanation of how a URI declaration
>>  establishes resource identity.
>>        The abstract:
>>        [[
>>        A URI declaration permits assertions about a URI's
>>  associated resource to be classified into two groups: core
>>  assertions, whch are provided by the URI declaration, and
>>  ancillary assertions, which are all others.  This distinction
>>  enables different parties to share a common understanding of
>>  the associated resource (by accepting the core assertions)
>>  while making different choices about which ancillary
>>  assertions to accept. This paper defines these concepts and
>>  proposes some related best practices and a Web architectural
>>  rule specifying how URIs for non-information resources can be
>>  conveniently declared using existing hash or hashless
>>  (303-redirect) URI mechanisms.
>>        ]]
>>        As usual, comments are invited.
>>  OK, you did ask...
>>  There is a basic problem with this idea and what you say
>>  about it. It comes to the surface here:
>>  "Definition: A URI declaration is a set of statements, or
>>  "core assertions", that authoritatively declare the
>>  association between a URI and a particular resource.
>>  A URI declaration is a performative speech act.  (See Cowen's
>>  message or Wikipedia.)  Its publication by someone who has
>>  the authority to make the declaration -- the URI owner or
>>  delegate -- defines the association between a URI and a resource.  "
>>  Wrong. Or, since a definition can't be wrong: with this
>>  definition, URI declarations do not exist; in fact, cannot
>>  possibly exist.
>>  No amount of just asserting can possibly create an
>>  association between a URI and a non-information resource,
>>  (unless it does so via some other URI which is itself
>  > 'associated' to a resource appropriately, but that just gets
>>  us into an infinite recursion.) There is no way of forcing a
>>  purely assertional framework, no matter how complex or large
>>  it is, to refer to anything non-linguistic or non-symbolic,
>>  by making assertions in the framework itself. (This can be
>>  formally stated as Herbrand's theorem: if a set of axioms has
>>  a satisfying interpretation at all, then it has one entirely
>>  made of its own symbols.)
>>  Its not a question of authority. You can have all the
>>  authority you want: but if all you can do is make assertions
>>  at me, no amount of authority is going to prevent me
>>  consistently understanding you as only talking about a
>>  symbolic world. I won't be rejecting what you tell me: you do
>>  have the authority to assert it, and I will accept it all as
>>  true. But it can all be true, and still not refer to what you
>>  want it to refer to. You can't possibly attach symbols to
>>  reality by symbolic means (like making assertions using the symbols).
>>  Just calling this a performative speech act doesn't work,
>>  either. In order to get a performative to work, you need to
>>  do something - perform a performative - with the thing
>>  involved in the act. The things involved in the speech act
>>  are part of the performance. The performative "I now
>>  pronounce you man and wife" works, in part, because it is
>>  said to the man and the wife themselves, in the flesh, so to
>>  speak. They have to be there to get married. Baptism,
>>  similarly, attaches a name to a child, and the child has to
>>  be there to get baptised. As John Cowan points out, in some
>>  cultures, simply saying "my real name is X' is enough to make
>>  your name X: but it has to be you that says it. Performatives
>>  always use indexicals (I, now, you, this) because they always
>>  need to be performed as part of an act involving the thing or
>>  person itself (or in some cases a person or thing
>>  appropriately associated with the thing or person, such as
>>  someone acting with power of attorney.)
>>  I could make detailed comments on the rest of the document,
>>  but this is enough. This idea of 'declarations' of
>>  non-symbolic, non-computational, non-informational entities
>>  just does not make sense. You can't declare the moon. Give up
>>  on the idea, its nonsense.
>>  Pat Hayes
>>  --
>>  ---------------------------------------------------------------------
>>  IHMC               (850)434 8903 or (650)494 3973   home
>>  40 South Alcaniz St.       (850)202 4416   office
>>  Pensacola                 (850)202 4440   fax
>>  FL 32502                     (850)291 0667    cell
>>  http://www.ihmc.us/users/phayes      phayesAT-SIGNihmc.us
>>  http://www.flickr.com/pathayes/collections

IHMC		(850)434 8903 or (650)494 3973   home
40 South Alcaniz St.	(850)202 4416   office
Pensacola			(850)202 4440   fax
FL 32502			(850)291 0667    cell
http://www.ihmc.us/users/phayes      phayesAT-SIGNihmc.us
Received on Friday, 29 February 2008 15:10:43 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 22:56:20 UTC