- From: Francesco Cannistrà <fracan@inwind.it>
- Date: Fri, 9 May 2003 11:07:52 +0200
- To: "Richard H. McCullough" <rhm@cdepot.net>, <www-rdf-interest@w3.org>, Dieter Köhler <dieter.koehler@philo.de>, "David Menendez" <zednenem@psualum.com>
> One can draw a parallel to Java here. Java has an Object class, which > all objects are instances of, and a Class class, which all classes > are instances of. Class is a subclass of Object, Object is an > instance of Class, and Class is an instance of Object. However: > Object is NOT a subclass of Class. I was sure that someone would have cited Java :-) I agree with everything you say, but I don't think that these are the terms of the question. What you say is either correct and precise, but it is only descriptive. When you say: > TRUE: > rdfs:Class rdfs:subClassOf rdfs:Resource . > rdfs:Resource rdf:type rdfs:Class . > rdfs:Class rdf:type rdf:Resource . > > UNTRUE: > rdfs:Resource rdfs:subClassOf rdfs:Class . you do not do anything more than reading the schema. The question is: is this a paradox? if yes or if not, why? I think that the answer to these questions cannot be direct, but that it depends on the meaning that we give to what we read in RDF Schema. I think that the real questions that solve the problem are: what is rdfs:Resouce? is it "defined" by RDF Schema through the schema it proposes? I do not consider the former question (whose answer, however, is not "Resource is a Class"), but about the latter I say: if the answer to this question is "no", then there is not any paradox, but if the answer is "yes", then we are in presence of a paradox: within a deterministic world an axiom is an axiom and cannot be demonstrated! Therefore, I think that there is not any paradox because I do not think that the schema of RDFS defines rdfs:Resource, it just gives a name to this concept. Maybe I'm wrong ... I'm concerned that these sound like metaphysical or ontological problems which nobody is interested to and/or takes care of; what is sure is that they do not affect anyway RDF's working fine. But ... ... does anybody know something about the Godel's theorem?
Received on Friday, 9 May 2003 05:08:07 UTC