RE: RE: SUO: Re: Ballot Comment - 3D versus 4D.
Adam,
The 3D and 4D views are well-documented, and well enough understood.
The sticking point for combining them seems to be:
3D: At each point in time that a continuant exists - it completely exists.
This implies that all its parts also exist.
4D: Typically a physical object is extended in time. If one is happy to talk
about time-slices, this means that at each point in time at which it exists
only a time-slice of this object exists.
BTW I think endurantist and perdurantist are better terms than 3D and 4D as
what is at stake is a view on what change is (see, for example, Chap 8 of my
book).
I am not sure how one can have a consistent theory that encompasses both -
and the people who write about this seem to take the same view (does anyone
disagree?). That is not to say that there cannot be a translation between
the two.
While I am pleased that you are beginning to see the underlying issues of 3D
vs 4D, I think you may be being extremely optimistic that you can solve them
in an afternoon - or less.
It would help the discussion if it was carried on in a relatively informed
basis. For a good introduction see Loux's 1998 Metaphysics Chap.6, and its
bibliography - for a good article see Merricks T, Endurance and
indiscernability, J. of Phil. 1994 - or even (though in nothing like the
same class :)) the paper I submitted to the SUO list on meta-ontology.
It seems to me that we going to waste everyone's time if there are good
resources for handling a topic and we ignore them and try and re-define the
problem and come up with instant answers to something people have spent man
years (at least) working on. Isn't this re-inventing the wheel at its worst?
Regards,
Chris
-----Original Message-----
From: owner-standard-upper-ontology@majordomo.ieee.org
[mailto:owner-standard-upper-ontology@majordomo.ieee.org]On Behalf Of Adam
Pease
Sent: 27 August 2001 16:41
To: West, Matthew R SITI-GREA-UK; 'pat hayes'
Cc: standard-upper-ontology@ieee.org
Subject: RE: RE: SUO: Re: Ballot Comment
Matthew,
Did you have any further comments on the logical representation I
presented in my message? That was the actual "meat" of the message and
where I think we have hope of some progress. I may be the eternal
optimist, but I think I found a solution that supports the 4d view that you
want. I've copied that portion below.
Adam
>If I understand you correctly, then you may be closer to the current SUMO
>representation than I thought. Here's a formalization in SUMO:
>
>(instance JoesArm OrganicObject)
>(instance JoesArmAtAge10 OrganicObject)
>(instance JoesArmAtAge20 OrganicObject)
>(spatioTemporalPart JoesArmAtAge10 JoesArm)
>(spatioTemporalPart JoesArmAtAge20 JoesArm)
>(equal (BeginFn JoesArmAtAge10) (BeginFn (YearFn 1990)))
>(equal (EndFn JoesArmAtAge10) (EndFn (YearFn 1990)))
>(equal (BeginFn JoesArmAtAge20) (BeginFn (YearFn 2000)))
>(equal (EndFn JoesArmAtAge20) (EndFn (YearFn 2000)))
>
>The key then is in the definition of a new relation for SUMO which we
>could call 'spatioTemporalPart' which would allow us to deduce
>
>(not (equal JoesArmAtAge10 JoesArmAtAge20))
>
>Now, at the danger of pointing out a flaw in this, we'd have to assume
>that no one who wants to use a 3d viewpoint would ever want to reify
>temporal sub-parts. Because from the above formalization, they'd want to
>conclude
>
>(equal JoesArmAtAge10 JoesArmAtAge20)
>
>I'm hoping though that this might be an acceptable compromise in terms of
>practical modelling support.
At 02:42 PM 8/26/2001 +0200, West, Matthew R SITI-GREA-UK wrote:
>Dear Adam,
>
>See comments below.
>
>
>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
>
>snip
> > > >
> > > > Matthew,
> > > > Ian's just pointed out to me problems with my response.
> > > > SUMO could
> > > > handle a 4d view but only in a trivial way by a knowledge
> > > > engineer putting
> > > > everything he cares about under the notion of Process and
> > > > thereby throwing
> > > > out the existing SUMO notions of identity that work on
> > > > Object. That's not
> > > > a good solution. I can see merit in both 3d and 4d views and
> > > > the challenge
> > > > is how to let them coexist in a meaningful way.
> > >
> > >MW: Unfortunately, you need to start probably above object.
> > >4D classes have unchanging extents, for example.
> >
> > I'm referring to Object in its sense in SUMO. The current
> > hierarchy is
> >
> > Entity
> > Physical
> > Object
> > Abstract
> >
> > etc.
> >
> > Do you feel a change is needed to axioms about Physical
> > <http://ontology.teknowledge.com:8080/rsigma/SKB.jsp?req=SC&sk>
> b=Merge-WordNet&id=95>?
>
>MW: Physical is close to the 4D concept of spatio-temporal extent. However,
>a 4D view would be that Physical Entities are parts of space time, not
>located
>in it. I presume location is meant in some co-ordinate sense, which is an
>abstraction. Before you can have an abstraction, you need to have something
>that forms the basis of abstraction, these are spatio-temporal extents,
>including
>one which is all of space-time (past, present, and future).
>
>MW: Existant has the concept of existing at one or more points in time. It
>is
>fundamental to a 4D view that existance is for a period of time. This is
one
>of the
>ways in which it differs significantly from a continuant based view which
>the SUMO
>has built in at a high level.
>
>MW: Also, a spatio-temporal extent can be quite arbitrary, rather as a set
>can have
>arbitrary members.
>
>MW: Another problem is that many of the things that you have as abstract,
>like roles,
>are temporal parts of things in a 4D ontology. I would therefore think it
>was safer
>to start above physical.
>
>MW: There are also problems with the abstract concepts. Our classes would
be
>extensional and
>unchanging. Properties and qualitities would be classes, and attributes
>might be either
>classes or spatio-temporal extents.
>
>MW: I.e. all abstract concepts would be classes/sets.
>
>MW: The best bet is to start with Chris M's Basic Set Theory and try to
>build something
>from there. However, it would be important to have a partition and probably
>a naming
>convetion so that 4D and 3D concepts can be distinguished.
>
>snip
Adam Pease
Teknowledge
(650) 424-0500 x571