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

Re: New version of URI Declarations [Usage scenarios]

From: Pat Hayes <phayes@ihmc.us>
Date: Fri, 14 Mar 2008 10:55:13 -0500
Message-Id: <p0623090dc4004d04bf42@[192.168.1.2]>
To: John Cowan <cowan@ccil.org>
Cc: "Booth, David (HP Software - Boston)" <dbooth@hp.com>, "www-tag@w3.org" <www-tag@w3.org>
At 11:06 AM -0400 3/14/08, John Cowan wrote:
>Pat Hayes scripsit:
>
>>  Well, this illustrates the problem, seems to me. Suppose I accept
>>  your claim that your URI denotes the moon, so that when I use it I am
>>  also referring to the same moon. But I want to point out that you
>>  said something false about the moon. Under your proposal, this is
>>  impossible. I can't say that, because by calling these assertions a
>>  'declaration', they have been removed from the domain of discussion.
>
>So they have, but that's unavoidable.

Of course its not unavoidable. That is merely a consequence of the 
mistaken idea that fixing a bunch of assertions is the same as fixing 
a referent. This idea is wrong. They aren't the same, and to assume 
they are gets one into a host of muddles, just like this one.

>  If we take the predicates "is a
>natural body", "orbits the Earth", and one more that I can't formulate
>exactly but is meant to exclude captured meteoroids if any there be,
>then these *define* the moon.

Not for ontological purposes. They might distinguish the actual moon 
from all other actual things in the actual universe, but that's not 
enough to define the moon at an ontological level. Ontologies can 
still disagree about what the term refers to (whether it is a 
continuant or not, for example.) And it depends on other things. 
There is some evidence that there is a second moon, in fact, in a 
very elliptical orbit.

>  If you contradict any of them, you are not
>talking about the moon any more.

If they are false of the actual moon, then I will need to contradict 
some of them in order to talk about the actual moon. You are begging 
the question by assuming that declarations are always correct and 
adequate. This is unrealistic.

>  (Another basis system could be given,
>such "occupied point P at time T" for appropriate choices of space and
>time scales; it matters not.)
>
>Note that none of these are essential properties in the Kripkean sense
>I was using before; essential properties are not necessary as long as we
>confine ourselves to the actual world and don't worry about contrafactual
>worlds.

Um... yes, necessary properties aren't much use, but no, we can't 
confine ourselves to the actual world. The formal reasoners don't 
have access to the actual world, and have to rely on consequences 
which hold in all possible worlds.

>
>However, once the moon is properly defined (= distinguished from all
>other objects to the extent possible or required), I can then make any
>number of assertions about it, any of which you may contradict, of course.

You are ignoring the central point. What if your 'defining' 
assertions are wrong, or contain a flaw of some kind? Does this 
change the reference (so they are not in fact wrong at all, just 
talking about something else) or is it a factual error? How can we 
even discuss this matter, if we cannot even contemplate the 
possibility that an assertion in a declaration might be false?

>
>>  Why should it be that by using a name correctly, given your
>>  intentions for using it, that I must therefore agree with everything
>>  you say about it?
>
>Not everything, only the assertions in the declaration (of identity).

OK, then it follows that YOU are using your own name incorrectly, 
right? This does not seem to fit well with the notion that an owner 
of a URI has control over what it denotes.

Pat

>
>--
>What has four pairs of pants, lives             John Cowan
>in Philadelphia, and it never rains             http://www.ccil.org/~cowan
>but it pours?                                   cowan@ccil.org
>         --Rufus T. Firefly


-- 
---------------------------------------------------------------------
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
Received on Friday, 14 March 2008 15:55:54 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Thursday, 26 April 2012 12:47:53 GMT