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

RE: [XRI] Cooler XRI

From: Drummond Reed <drummond.reed@cordance.net>
Date: Fri, 24 Oct 2008 11:58:36 -0700
To: "'Pat Hayes'" <phayes@ihmc.us>, "'John Bradley'" <jbradley@wingaa.com>
Cc: <www-tag@w3.org>
Message-ID: <2B62600D13354FCA9411DCFF7AE589E4@ELROND>
Pat, I don't know about anyone else on the XRI TC, but I'd like to avoid
such a philosophical trench in the worst way. So I will stop using "Platonic
ideal" and go back to "thing" immediately. Frankly I agree with you that
"entity" is the best English candidate I know of, given that after six
months of careful consideration that's what the Higgins Project settled on
this summer, but in informal conversations "thing" will do just fine.


Just my personal view.





From: www-tag-request@w3.org [mailto:www-tag-request@w3.org] On Behalf Of
Pat Hayes
Sent: Friday, October 24, 2008 10:10 AM
To: John Bradley
Cc: www-tag@w3.org
Subject: Re: [XRI] Cooler XRI



On Oct 24, 2008, at 6:54 AM, John Bradley wrote:

We all now understand that:

          * If an "http" resource responds to a GET request with a 2xx
response, then the resource identified by that URI is an information
          * If an "http" resource responds to a GET request with a 303 (See
Other) response, then the resource identified by that URI could be any
          * If an "http" resource responds to a GET request with a 4xx
(error) response, then the nature of the resource is unknown.
Givin this understanding the "Cool URI" document shows us how to construct
URI for "real-world objects or things".

As it happens every XRI is also about a "thing".  We have attempted to come
up with better language than "thing".

I quite like the description used by Stuart Williams of "Platonic ideal" in
that when I the XRI =jbradley to refer to me I am not literally refering to
me but to an ideal of me that can be descibed by meta-data in the same way
that a mathmatician describes a circle via a formula.
Both myself and any phisical circle are crude appoximations of the ideal.


I would beg you to reconsider this idea. You have just stepped into a
philosophical trench so deep that only a few specialized submersibles can
plumb its depths, and survival without specialized aids is impossible.
Unless you are prepared to deal with the elaborate and expensive equipment
needed (a graduate degree and an established publication record in
philosophical metaphysics is an absolute minimum) I would strongly urge you
to stick to the innocuous terminology of "thing". This is not language that
needs to be improved: its very banality is its power, as what is wanted at
this point is a term for something that can be, literally, anything. (The
philosophical word "entity" would have more resonance, but it has already
been co-opted by XML for a completely different purpose.) All that actually
matters for Web architectural discussions, in any case, is that there are
some, er, things that cannot be sent over a byte stream, and that some names
(URIs, XRIs, whatever) are required to denote such things. Further
philosophical stipulation about the nature of these things is a topic that
belongs to philosophy rather than to Web science. And to repeat my appeal,
please, please do not engage in philosophy unless you are seriously prepared
for the resulting debates. It is not a game for amateurs to play. 


Allow me to point out some of the issues that immediately arise, but would
not have done if you had not tried to invoke the ghost of Plato. 

Givin that the XRI =jbradley names the PI(Platonic ideal) me how do I use
that as a URI?

I can use the proposed sub scheme for a http: XRI and put the relative XRI
on a base http: URI:


Now if this URI returns a 303 and link header information about where to
retreve meta data about =jbradley and perhaps alternate resources relating
to =jbradley based on content negotiation it is by the W3C's definition  a
cool URI.


True, but it refers to a Platonic Ideal. I, personally, would have no idea
how to even begin composing metadata about a Platonic Ideal of a particular
person. What is there to say about such a thing? One could not possibly use
this in FOAF, for example, or with any properties from Dublin Core, since
Ideals don't have friends or engage in authorship.

The cooler part is that we now have the XRI shared semantics that can be
applied to any XRI subsceme URI to describe =jbradley.


Evidently, your Ideal, which this XRI/URI apparently describes, is not you,
since you live in the physical world and it does not. So now we have (at
least) two John Bradleys to content with: the Ideal one, referred to by an
XRI/URI, and the actual one which another URI might denote, protected by 303
redirects. I could describe the class of these two things using owl:oneOf
and it would have a cardinality of two. Maybe you want this to happen,
though I cannot see any purpose for it. It means for example that listing
the XRI-Ideal-you as being in a class of Wingaa employees would be a
category error. 


You could try writing a special OWL ontology for handling the
Ideal-to-real-thing relationships. Some questions arise immediately. Can a
thing have more than one Ideal? Can an Ideal be the Ideal of more than one
thing? In both cases, there are good arguments both ways, some of them
venerable. I guess it would be up to a special philosophical XRI working
group to decide such questions (and there are of course many more of them:
what kinds of properties can be attributed to an Ideal?), but until they are
resolved, XRIs will not be usable along with URIs to talk about real-world

This is achieved through a mechanism simmilar to the one that the W3C
recommends near the end of "Cool URI".  They cite D2R Server as an example
of using SPARQL and 303 redirects to serve RDF documents about "Platonic


I don't see anything in there about Platonic Ideals, with or without scare
quotes. BTW, using scare quotes in philosophy is never done. It is an open
declaration that you know you don't know what you are talking about. 


Pat Hayes



IHMC                                     (850)434 8903 or (650)494 3973   

40 South Alcaniz St.           (850)202 4416   office

Pensacola                            (850)202 4440   fax

FL 32502                              (850)291 0667   mobile

phayesAT-SIGNihmc.us       http://www.ihmc.us/users/phayes




Received on Friday, 24 October 2008 18:59:21 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 7 January 2015 15:32:59 UTC