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Re: article on URIs, is this material that can be used by the SWEO IG?

From: Pat Hayes <phayes@ihmc.us>
Date: Thu, 31 May 2007 00:05:30 -0700
Message-Id: <p0623090cc2841fd8ca9e@[192.168.1.4]>
To: John Cowan <cowan@ccil.org>
Cc: John Cowan <cowan@ccil.org>, Leo Sauermann <leo.sauermann@dfki.de>, www-tag@w3.org

>Pat Hayes scripsit:
>
>>  > For example,
>  > >http://en.wikipedia.org/wiki/Shakespeare is a subject indicator for
>  > >Shakespeare.
>>
>>  But it also mentions Stratford-on-Avon, Mary Arden, and many other
>>  things. Why is it not just as much 'about' them?
>
>Because I don't so employ it.

OK, fair enough. But then it follows that there is nothing 
*intrinsic* to that resource that makes it be a subject indicator for 
Shakespeare. It is so simply because you say it is. But when I read 
that resource, how do I gain access to *your* intention that it shall 
be a subject indicator? What readable resource is it that tells me 
that http://en.wikipedia.org/wiki/Shakespeare is a subject indicator 
for Shakespeare ?

>  In principle it could be.  In my judgment,
>there are other clearly better subject indicators for those resources.
>
>Two resources identified by the same subject identifier (or
>in fact with the same subject-indicator-reference URI)
>are the same.

How can a single URI identify two different resources?

>
>>  And what does THAT mean? This notion of a thing's "identity" seems to
>>  be very freely used in W3C circles, but I have no idea what it is
>>  supposed to mean. What kind of things have an "identity"? Does a
>>  grain of sand on a beach have an identity? It is certainly identical
>>  to itself: is that enough?
>
>Yes, in principle, but we don't worry about the identity of things
>which are not the subject of any predications.

But it is trivial to predicate about grains of sand on a beach. The 
sand on Pensacola beach, every grain of it, is made of quartz, and so 
the beach is pure white. There: in the previous sentence I asserted a 
predication of every grain of sand on a beach. So, do all those 
grains now have an identity?

>  If I go to the water
>tap and fill a cup with water, there is now a glob of water of which
>we can say "It is in the cup".  Before, there was no such "it"

Of course there was. It was in pipes rather than in the cup, and it 
had a different shape, but it certainly existed. If the pipes are 
contaminated with lead, you had better not drink the water in the cup.

>;
>the glob of water lacked any useful identity.

"Useful" opens up a whole new can of worms. Im not particularly 
interested in useful identities: I just want to know what it means to 
say that something has (and that something else lacks) an identity of 
any kind.

>
>>  Apparently Shakespeare has an identity,
>>  but I wouldn't recognize him if I were to meet him in the street. If
>>  someone were to tell me something about Shakespeare I would indeed
>>  feel that I knew who the fact was 'about', but is this anything more
>>  than just familiarity with the name?
>
>There are lots of facts we can predicate about Shakespeare; his life
>is rather well-documented for a person of his place and time.

True. So what? Does the presence of enough facts make something have 
an identity? If so, how many facts is enough? What is the threshhold 
of factual knowledge that creates this mysterious identity-ness?

>Some people assert that some of these facts are wrongly predicated
>about Shakespeare, like "wrote Hamlet".  Nobody, as far as I know,
>says that Hamlet was written by some totally unknown person, but
>if it turned out to be true, that person would be identified as
>separate from Shakespeare.

That person would not be Shakespeare. Is that all you mean by your 
phrasing? Or does your use of "identified as separate" imply 
something other than simple inequality? (I find this example 
puzzling, in fact, as presumably if a person is indeed unknown, then 
surely he or she is not identified at all (??) After all, we can be 
fairly sure that Shakespeare is not, say, my toaster oven: but that 
fact about him is not usually thought of as "identifying" him as 
"separate from" my toaster oven. How does this case differ from your 
example?)

>
>>  I would feel the same if someone
>  > were to use the name, say, "Rauschenberg", but about all I know about
>>  Robert Rauschenberg is that he is, or was, a notable American
>>  contemporary artist. Is this enough to give him an "identity"? How
>>  much information about a thing is enough to establish an identity for
>>  that thing?
>
>If there is something you can assert about Rauschenberg, like "is a
>notable contemporary artist" or even "is named 'Robert Rauschenberg'",
>then at least you know that he is not Willem de Kooning or Buckminster
>Fuller or Paganini.

Why do I know that? For all I know, Willem de Kooning might be a nom 
de plume for Rauschenberg. But in any case, you havn't answered my 
question. Is *any* fact about a thing enough to give that thing an 
identity? It would seem to follow that everything has an identity, 
since we know some facts about every thing (such as that it is equal 
to itself).

Pat Hayes

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Received on Thursday, 31 May 2007 07:06:12 GMT

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