Re: SUO: Logic and Ontology
On 3/5/02 09:10, "West, Matthew R SITI-ITPSIE" <Matthew.R.West@is.shell.com>
wrote:
>
> Dear Colleagues,
>
> I was recently sent a copy of Axiomathes, and noticed a paper
> with the above title.
>
> Cocchiarella, Nino B.; "Logic and Ontology", Axiomathes 12: 117-150, 2001
>
> The part of the paper that interested me was the different
> interpretations that could be made of predication, depending on
> whether your basic ontology is based on nominalism, conceptualism,
> or realism (or some graduation between).
>
> One of these, attributed to Quine, sems to coincide with my own
> interpretation of predication, and I repeat it here.
>
> "Quine's understanding of his ontology as platonistic and of sets
> as universals is based on a rather involuted argument, the essentials
> of which are as follows: if we were to adopt platonism as a theory of
> universals as represented by higher order logic in which predicate
> as well as individual variables can be bound, then
>
> 1. predicate quantifiers can be given a referential ontological
> interpretation only if predicates are (mis)construed as singular
> terms (i.e. terms that can occupy the argument or subject positions
> of predicates); and
>
> 2. assuming extensionality,
That's a big assumption. I have to think this through better but if you
make this move then you're committed to something like Lewis' view where a
predicate like "Beer" applies to all the beer there is, anywhere, at any
time (thus extensional). On this view "Beer" can't apply conditionally to
individuals at worlds or at times.
So, accepting the view of predication that you want is asking a lot from
those who don't buy extensionality (this extensionalism carries several not
insignificant ontological burdens of its own in exchange for a clean theory
of predication) or who are actualists but still want statements like "There
could be more beer than what there is" to come out as true. Given that,
there is no basis to call the basis of predication in KIF into question.
After all, it's just a logic and you're being a little hard on it, don't you
think?
That said, I think you've raised a good issue to think about. Those who
know a lot about Lewis and Quine please chime in here, but I think I have
the basics right.
.bill