Re: SUO: intention vs. extension again
>Pat,
>
>Comment below.
>
>pat hayes wrote:
> >
> > >Jon,
> > >
> > > That's just the case the raises the problem. If C1 and C2 have
> > >contradictory meanings associated with them and both of them have no
> > >extension (i.e. both of them are associated with the empty set),
>then there
> > >is no actual object which is an instance of C1 and is not an
>instance of C2.
> > >Hence, the two classes would not be disjoint, according to the standard
> > >extensional criterion of disjointness. However, since it is
>impossible for
> > >any instance to be a member of both classes, the classes are disjoint
> > >according to an intensional criterion. The question, then, is whether we
> > >want to go with an extensional or an intensional criterion of
>disjointness.
> >
> > The issue is whether or not you want to go with an intensional notion
> > of class. Half of me wants to urge you to do so, as that will finally
> > seal the fate of the merged ontology, but such a thought would be
> > unworthy.
>
>I am not sure what you mean by this; apparently this would be the kiss
>of death for the merged ontology. But why?
In my opinion, it makes class reasoning unworkable. It is also based
on a fallacious idea about the relevance of modal/intensional
reasoning to ontology design, basing it on an analogy to ordinary
English or NL discourse (see my reply to Chris Menzel earlier today.)
Incorporating two such fundamental conceptual errors into the
foundations of the SUO would make it completely unusable by me, for
sure, and I suspect by folk like Matthew West and Doug Lenat: anyone
who wants it to support nontrival chains of inference. It would make
the SUO incompatiable with almost all industrial-scale ontologies
written in description logics like CLASSIC or LOOM, many of which are
now international de facto standards.
Pat Hayes
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