Re: SUO: RE: Axiom and Intentionality vs Extentionality
Thank you for your reply, Ian.
You have agreed that my example of a left-handed leprechauns that play the
trombone is a meaningful class. And I understand that you are saying that a
collection must have an extension in space-time. By this I assume you mean
that it must exist in documented history.
What it the SUMO supports non-documented history? For example, If I want to
store in my ontology fictional creations, (such as I have given here) or
personages such as Sherlock Holmes, I would hate to copy the entire ontology
based on Collections, with something-like-Time and something-like-Space
just to say that Sherlock smoked an something-very-like-a-pipe except that
it never could have existed.
Also, how would you handle the (most people agree as real) dinosaurs that
might have reptilian skin or might have bird feathers, which we have fossils
that showed they existed, but not enough evidence (perhaps yet) to decide
the reptile vs bird argument ? This is (by most people's agreement)
history, and can be assigned a place and time, but still not a very exact
one, and generally guesses exist but not enough hard evidence to convince
everyone.
--David
>
>
> Hi David,
>
> Thanks for your message. See my comments below.
>
> -Ian
>
> > -----Original Message-----
> > From: David Whitten [mailto:whitten@lynx.eaze.net]
> > Sent: Friday, November 02, 2001 12:07 PM
> > To: standard-upper-ontology@ieee.org
> > Subject: SUO: Axiom and Intentionality vs Extentionality
> >
> >
> >
> > I was looking at the SUMO browser at:
> >
> > http://128.136.11.33:8080/rsigma/SKB.jsp?req=SA&skb=Merge&id=260
> >
> > where the axiom:
> > Formula
> > (=>
> > (instance ?COLL Collection)
> >
> > (exists
> > (?OBJ)
> > (member ?OBJ ?COLL) ) )
> >
> >
> >
> > Now, as I read this, if a collection exists, it MUST have a member.
> > I understand that the SUMO semantics for member and Collection are:
> >
> > (documentation member "A specialized common sense notion of
> > part for uniform
> > parts of &%Collections. For example, each sheep in a flock of
> > sheep would
> > have the relationship of member to the flock.")
> >
> > (documentation Collection "Collections have &%members like
> > &%Classes, but,
> > unlike &%Classes, they have a position in space-time and
> > &%members can be
> > added and subtracted without thereby changing the identity of the
> > &%Collection. Some examples are toolkits, football teams, and
> > flocks of
> > sheep.")
> >
> > Now, it seems to me that this axiom requires a collection to have an
> > instance.
>
> That's right, and this is as it should be, I think, since collections are
> supposed to be situated in space/time and this wouldn't be possible for a
> collection that had no members.
>
> >
> > Maybe I'm being obscure, but I would hope that this doesn't
> > say that there
> > are no such things as intentional collections in the SUMO ontology.
>
> I think you need to spell out what you mean by an intensional collection.
> Note that, in the usage of analytic philosophers, the term is spelled with
> an "s" when it's opposed to "extensional".
>
> >
> > I don't know how many left-handed leprechauns that play
> > trombone exist, but
> > I would think that I should be able to express in SUMO the
> > collection of them
> > without wandering around looking for a pot of gold to give
> > the guardian a
> > survey (to see if he/she is one) first.
>
> Well, we can, within the framework of the SUMO, create the *class* of
> left-handed leprechaus that play trombone, since this is a meaningful
> concept. Why do you think we should also be able to create a collection
> corresponding to this class? If you think this should be possible, you need
> to spell out what your notion of *collection* is and you need to show how it
> is distinguished from the SUMO concepts of class and collection.
>
> >
> > David Whitten (713) 791-1414 ext 6116
> >
> >
>