SUO: RE: Axiom and Intentionality vs Extentionality
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
>
>