Re: SUO: RE: Logic and Ontology
On Tue, Mar 05, 2002 at 06:26:16PM +0100, West, Matthew R SITI-ITPSIE wrote:
>
> Dear Seth,
>
> I am loath to try to descibe other peoples view of the world. You
> almost innevitably misrepresent them. Still subject to correction
> here goes.
>
> If you have what I would call a "property" view rather than a "set"
> view then you think that the properties that a thing has change
> over time, and that the things that have the property have changing
> membership. These properties therefore can't be sets (whose membership
> does not change) so when you say:
>
> (red mycar)
>
> you are not asserting set membership but something else. Whatever that
> is is what predicate means for those with that viewpoint.
I'm not sure I see this: one thing you can say is that something like
'(red car01)' is evaluated in a domain _at a time index t_, and that it
is evaluated as True iff [[car01]]_t belongs to [[red]]_t, where the
latter term is defined as: the set of things that are red at t.
You might even add that the 'property' [[BeingRed]] is a function from
times to the powerset of the domain such that [[BeingRed]](t) =>
[[red]]_t. (This assuming you have a fixed domain and set of indices, in
the simplest case.) The point is, I don't quite see how predication of
properties and set membership are somehow incompatible here (I suspect
that is not what you meant... I feel I have lost sight of your original
intent about the predication/membership distinction).
>
> As a cross reference the 4D viewpoint would say that a state of the
> car was red, and that red was the set of all states that were red,
> past, present and future, so the membership is unchanging, actually
> time is taken out of the equation, and red really is a set.
Again, something looks strange to me: 'a state of the car was red' and
'red = the set of all states that were red' taken jointly seem
incoherent. The standard move here is to distinguish 2 senses: so one
would say 'the state of the car was red_2' and 'red_1 = the set of all
states that were red_2', where red_2 is presumably the denotation of the
predicate 'red' in assertions like (red car01). Then the relation between
red_2 and red_1 would be somewhat analogous to that between the set of
things that are red a time and the property of redness on the previous
construal.
Also, I suppose that 4-D would rather require that not cars, but temporal
parts of cars, can be red_2. Cars themselves, as 4-D timeworms, would
have instead the property of overlapping with the fusion of red_1
(or iow: some of the temporal parts of the worm that is car01 would be
elements of red_1, which is to say, would overlap the mereological sum of
red_1, if I understand how these sums work).
regards,
>
> Matthew West
> Principal Consultant
> Shell Information Technology International Limited
> Shell Centre, London SE1 7NA, United Kingdom
>
> Tel: +44 20 7934 4490 Other Tel: +44 7796 336538
> Email: matthew.r.west@is.shell.com
> Internet: http://www.shell.com
>
>
> > -----Original Message-----
> > From: Seth Russell [mailto:seth@robustai.net]
> > Sent: 05 March 2002 16:54
> > To: West, Matthew R SITI-ITPSIE; Standard-Upper-Ontology (E-mail)
> > Subject: Re: Logic and Ontology
> >
> >
> > From: "West, Matthew R SITI-ITPSIE" <Matthew.R.West@is.shell.com>
> >
> > > The bottom line here as far as I can see is that without stating
> > > a particular meaning for predication, KIF is ambiguous. Or perhaps
> > > I should say that when you use KIF, you need to state the meaning
> > > of predication you are using.
> >
> > Could you provide us with a tangible example giving differing
> > meanings of
> > predication?
> >
> > Seth Russell
> >
> >
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