Folks,  (01)
I was amazed to see the collection of comments that appeared overnight
on this thread. I agree with Pat that syntax is a lot easier than
metaphysics, and it can often lead to useful formalisms that cut
through many centuries of philosophical debate.  (02)
To satisfy both the philosophical and computational requirements,
I'd like to outline an approach that I have found useful, and which
I have developed in more detail in my books and articles:  (03)
 1. As a basic metaphysical stance, I prefer a 4D ontology, which
 considers the whole universe from a God's eye point of view,
 as one giant domain of discourse.  (04)
 2. Point #1 guarantees that there is no problem about quantifying
 or referring to entities and things in the past or future. But
 it doesn't provide a convenient way of referring to plans for
 the future (which might not exist) or fictional things like
 Sherlock Holmes (about whom we know a lot of details that
 never happened).  (05)
 3. Point #1 might be convenient for God, but it's often awkward
 to relate to our everyday language. We need a formalism
 (syntax) that can be related to the domain of #1, if necessary,
 but can also be related to extended domains that can talk
 about hopes, fears, plans, hypotheses, alternatives,
 counterfactuals, fictional, and mythical entities.  (06)
 4. As a convenient 3+1 D way of talking, thinking, and computing,
 I like the notion of a *situation* as a finite chunk of space-time
 that could be mapped to some region in domain #1, but it could
 also be mapped to a domain that may include some part of #1 and
 any arbitrary set of set of anything anybody would like to think
 about or talk about. Think of those entities as mathematical
 objects, which mathematicians freely assume whenever they please.
 But they might be virtual reality things like Sherlock Holmes,
 since VR objects that look like people are just as mathematical
 as spheres or cubes.  (07)
 5. Given the option of having the whole 4D universe as a ground
 domain plus the option of throwing in any kind of VR entities
 we'd like to think or talk about plus situations that can
 include any mixture of any of the above, we get a rich semantic
 domain plus a rich syntactic system -- and fortunately, we can
 formalize it in Common Logic, if we wish.  (08)
 6. I agree with Ronald that signs need not have concrete physical
 things as their referents. (The medieval Scholastics talked
 about "suppositions" as the referents for terms whose concrete
 referents were nonexistent or at least dubious.) The domain
 of #1 enriched with the domain of #4 gives us enough entities
 to support almost any metaphysics anyone might like.  (09)
 7. I have no sympathy with people like Quine who try to limit
 the number of things in the ontology, but still allow infinite
 sets to support anything that the mathematicians might dream up.
 If you allow mathematics into the domain of quantification, then
 you have uncountable infinities of virtual reality in your domain.
 That should be enough to satisfy anybody.  (010)
John  (011)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/ 
Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/ 
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/ 
To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx  (012)