W3C home > Mailing lists > Public > www-rdf-interest@w3.org > May 2003

RE: rdfs:class and rdfs:resource

From: andrew cooke <andrew@acooke.org>
Date: Wed, 7 May 2003 22:34:17 -0400 (CLT)
Message-ID: <60187.127.0.0.1.1052361257.squirrel@127.0.0.1>
To: www-rdf-interest@frink.w3.org


Couldn't you argue that "Class" really belongs to a meta-language?  But
no-one really want to deal with a metalanguage as well as a language (and
anyway, wouldn't you then need a meta-meta-langauge?).  So instead, it's
stuck back into the base language and, since it is something in that base
language, it's a Resource.

It's not Russell's paradox, but they share the same source - mixing the
meta and base languages (for a paradox you need to add half a twist of
negation).  Is it obvious to someone that by doing this you don't open a
door to the paradox?

Forgive me if this is hopelessly naive, I'm new to this.

Andrew


James Rothering said:

>
> Thanks to everyone on attempting to clarify this rdfs:class and
> rdfs:resource issue. But, either I'm missing something, or these
> explanations are. Specifically, I need to see a careful description of the
> classes and *instances* involved.
>
> My take on this was that you had these as schema items, following the OO
> hierarchy level on the left hand side:
>
> Class        rdfs:Resource
> Subclass     rdfs:Class
> Subsubclass  exmpl:ExampleClass
>
> Now, moving from schema classes to instances, one notes that:
>
> instance exmpl:ExampleClass is therefore an instance of an rdfs:class and
> in
> turn, since rdfs:class is a subclass of rdfs:Resource, therefore it is
> also
> an instance of rdfs:Resource, right? In other words, it could in be "cast"
> as either the highest level superclass rdfs:Resource or the one-level
> higher
> superclass rdfs:class.
>
> This makes the rdfs:resource class the root class.
>
> The paradox here is that the notion of a class called resource is
> introduced
> before the notion of class! So, really, logically, they have to arise
> together. But, one resolution could be that rdfs:Resource is both root
> class
> and an instance of rdfs:class?
>
> OK, so this doesn't help either, does it?
>
> Regards,
>
> James
>
>
>
>


-- 
http://www.acooke.org/andrew
Received on Wednesday, 7 May 2003 22:41:16 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:51:59 GMT