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Re: [ontolog-forum] Truth

To: ontolog-forum@xxxxxxxxxxxxxxxx
From: John F Sowa <sowa@xxxxxxxxxxx>
Date: Thu, 05 Jul 2012 08:03:31 -0400
Message-id: <4FF58293.30705@xxxxxxxxxxx>
After the discussions in this thread last week, I browsed through
some papers by Peter van Inwagen, a philosopher who writes about
ontology and related topics:    (01)

    Papers by Peter van Inwagen    (02)

The following paper covers some of the points I was trying to make
about simplifying the terminology for teaching ontology:    (03)

    Relational vs. Constituent Ontologies    (04)

A relational ontology, which he favors, has a straightforward mapping
to logic.  It consists of things that you can refer to by quantified
variables and the relations that relate those things to one another:    (05)

> My own favored ontology can serve as an example of a relational ontology.
> According to this ontology, members of the primary category that can be
> variously called “substance,” “concrete thing,” “individual thing,” and
> “particular thing” are without ontological structure...
> everything that is not a particular thing is an abstract object or relation
> (a proposition, property, or proper relation). And there is no possible
> sense of ‘constituent’ in which an abstract object can be a constituent
> of a substance/concrete particular/individual thing...    (06)

This is the kind of ontology that you can map to predicate calculus
to any dialect of Common Logic, or to RDF and OWL.  Van Inwagen
contrasts it with constituent ontologies:    (07)

> A constituent ontology, like a relational ontology, includes “concrete
> particular” in its inventory of ontological categories. But, unlike
> relational ontologies, constituent ontologies imply that concrete
> particulars  have an ontological structure: they have constituents
> (perhaps parts in  the strict sense, perhaps not) that do not belong
> to the category  “concrete particular.”    (08)

Among the constituents in such theories are things like tropes and
universals.  For example, a horse is a concrete particular that has
flesh and bone as concrete parts, but it also has a universal, such
as horseness, as a constituent.  When the horse is happy, it would
have the trope happiness as a constituent.  Van Inwagen writes:    (09)

> I will now give some reasons for preferring a relational to a constituent
> ontology—reasons for repudiating the idea of ontological structure...
> My principal reason...is a very straightforward one: I do not understand
> the idea of ontological  structure or, indeed, any of the ideas with
> which one finds it entwined  in the various constituent ontologies.    (010)

When van Inwagen says he doesn't understand constituent ontologies or
the ideas entwined in them, I despair of teaching them to people who
need to use ontology in computer systems.    (011)

> I do not understand the words and phrases that are the typical
> items of the core vocabulary of any given constituent ontology:
> ‘Immanent universal’,  ‘trope’, ‘exist wholly in’, ‘wholly present
> wherever it is instantiated,’  ‘constituent of’ (said of a universal
> and a particular in that order).  These are all mysteries to me.    (012)

An immanent universal, for example, is the horseness that is present
in every particular horse.  As an example, van Inwagen quotes a passage
by the philosopher David Lewis:    (013)

> [Consider] two particles each having unit positive charge. Each one contains
> a non-spatiotemporal part corresponding to charge. [It is a universal and] the
> same universal for both particles. One and the same universal recurs; it is 
> located; it is wholly present in both particles, a shared common part whereby 
> two particles overlap. Being alike by sharing a universal is ‘having 
>something in
> common’ in an absolutely literal sense.    (014)

Talking about atomic particles shifts the focus to something that is
mysterious even for physicists.  But if you replace the particles
with something more familiar like horses, you get    (015)

DL with horses:
> One and the same horseness recurs; it is multiply located; it is wholly
> present in both horses, a shared common part whereby the two horses
> overlap.  Being alike by sharing horsenesss is ‘having something in
> common’ in an absolutely literal sense.    (016)

A biologist would say that the two horses contain copies of the same
kind of DNA.  But the DNA is a "concrete particular", not a universal.
Each horse has its own DNA, and there is no overlap.  Van Inwagen said    (017)

> Such talk bewilders me to a degree I find it hard to covey.    (018)

In any case, van Inwagen writes clearly about a broad range of topics
related to ontology and other philosophical issues.  I recommend
his writings.    (019)

He is also sympathetic to people he criticizes.  For example, he wrote
the following review of collected papers by David Lewis:    (020)

    http://andrewmbailey.com/pvi/Review_Lewis.pdf    (021)

He gives Lewis high praise and credit for his strengths (originality,
mastery of analytical technique, prose style, broad and deep knowledge
of the field).  He strongly recommends many of the papers in the
collection, but he is also critical of some issues, such as the example
above, or of Lewis's notorious "Extreme Modal Realism".    (022)

John    (023)

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