RE: SUO: Metaphysics: a book report (long message)
Dear Pierluigi,
Welcome!
See some 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
> -----Original Message-----
> From: Pierluigi Miraglia [mailto:miraglia@cyc.com]
> Sent: 06 September 2001 15:57
> To: Adam Pease
> Cc: standard-upper-ontology@ieee.org
> Subject: Re: SUO: Metaphysics: a book report (long message)
>
>
>
> Hello. Since this is my first post, a self-introductory bit
> might be in
> order: I work at Cycorp as an ontologist; a good portion of my time is
> spent on 'temporal reasoning' issues. My training is as a
> philosopher of
> logic and language.
>
> Thanks for this stimulating report. A few comments below; apologies if
> these issues have been already addressed in the past (I joined only
> recently).
>
> On Wed, Sep 05, 2001 at 08:24:23PM -0700, Adam Pease wrote:
> ....
> > "Typical endurantists are what we might call
> presentists...only what exists
> > in the present really exists."
>
> Does Loux say much about the distinction between 'exists' and 'really
> exists'?
>
> > "Perdurantists [assert that] ... all times, all things
> existing at those
> > time...are equally real."
> >
>
> Including things that may exist only in possible futures? Are these
> considered at all?
MW: Yes, a possible worlds approach of some sort can deal with
possibility, and even fiction.
> It seems that it would be coherent, from a
> perdurantist standpoint, to say that there is a 'space-time worm',
> somewhere in the 4d continuum, would have been my brother,
> if only the
> chain of time points corresponding to the actual development
> of the world
> had gone through that 'forgotten' region.
MW: Yes. Space-time worm is a good analogy for how perdurantists
see objects.
>
> > The former seems practically incoherent to me and can be
> addressed just by
> > a matter of modeling convention in which every statement is
> wrapped in an
> > implicit (holdsIn Now (...)) unless otherwise specified.
>
> Things could be interpreted that way, I think. OTOH, this doesn't seem
> very practical either, unless we are prepared to change all
> such holdsIn
> statements as the meaning of Now changes. Isn't it just
> simpler to regard
> all statements as true at some time, i.e., implicitly tensed?
MW: Some databases and probably knowledge bases do not attempt to do
more than record what is true now. As now changes the content of the
data/knowledge base is updated to reflect the current state. History
is lost, or may be stored using an audit trail approach. This is really
quite a weak approach to understanding and managing change.
>
> (Why do you think the former would be practically incoherent?)
>
> > Loux also gives some nice analogies between 3d vs 4d as a
> debate similar to
> > possibilism vs actualism.
> >
> > Loux goes on to discuss an odd position of some
> perdurantists that assert
> > that groups of entities that seems disconnected in a common
> sense view of
> > the world such as "Big Ben from ... noon to ...
> midnight...and Wmbley
> > stadium from 2pm to 3pm..." are just as real as the group
> "...the Loux of
> > yesterday and the Loux of today".
>
> I don't perceive this position as very odd, perhaps because
> my intuition is
> that an endurantist would have no beef with it: of course, the Big Ben
> Dickens looked at is just as real as the Big Ben of today --
MW: Not ofcourse at all!! only from a particular metaphysical perspective.
I coudl just as well say that only what is real now is real, and that the
Big Ben of Dickens is not real now.
> they are the
> same thing (says the endurantist). BTW, the _same_ Big Ben is
> also the one
> Sherlock Holmes could have looked at.
>
> The perdurantist of course denies that we have one Big Ben here, at
> different times (and possibly in different modal contexts).
MW: One advantage of perdurantism is that you can avoid modal logic.
> Instead we
> have 2 parts of a peculiar type of thing that is never fully
> there at any
> particular time.
MW: Peculiar is a rather perjorative word. A perdurantist sees the whole
object as being its whole life.
> Do I understand correctly?
MW: If it seems peculiar, probably not.
>
> ......
> > JoeBeforeT, JoeAfterT, JoePartOtherThanHisArmBeforeT,
> >
> > Before amputation we have both Joe and the part of Joe without his
> > arm. Endurantists also believe that Joe survives the loss
> of his arm with
> > his identity intact. After the amputation we have only a
> Joe without his
> > arm. This leaves us with the assertions that Joe is the
> same as both Joe
> > before the amputation as well as the more clearly true
> statement that Joe
> > after the amputation is the same as the spatial part of Joe
> minus his arm
> > before the amputation. Thanks to the Indiscernibility of
> Identicals
> > though, they can't both be true.
> >
>
> Having an arm is a property that is 'tensed' or
> time-sensitive. Being Joe
> is not: I don't have a new friend now that Joe, poor fellow,
> has lost an
> arm. I have the same old friend, who's suffered grievous
> bodily harm. So
> it doesn't seem that there is any violation of the indiscernibility of
> identicals here: the same thing is F at time t, and not-F at
> time t'. It
> doesn't have, at least at first blush, inconsistent properties.
>
> The PD would have to say, as I understand it, that it doesn't
> make sense
> for me to say that I have a friend: the proper way of speaking of such
> things is rather, "My time slice at t is friend with a
> fully-limbed joe-time-slice, but at my time-slice at t' is
> friend with a partially-limbed joe-time-slice." There is no such
> thing as real friendship, it seems, except among time-slices.
>
MW: Yes, if you time index everything to do with individuals you can
get to something which can capture most of the history of things. But
as I have pointed out elsewhere, 3D also invites a "current state"
approach, which I consider somewhat inadequate.
>
>
> > The Endurantist responds however in several ways
> >
> > 1. There are different notions of identity. One notion is
> strict and
> > requires all parts to be present. The other is informal.
> So the two
> > problematic statements are actually using incomparable identity
> > relations. This position is attributed to Roderick Chisholm
> >
> > 2. Peter Geach also asserts that there should be different
> notions of
> > identity but says instead of just two as in (1) that they
> should be with
> > respect to a particular class.
> >
> > 3. Peter Van Inwagen offers that there is no such thing as
> arbitrary
> > undetatched parts an so JoePartOtherThanHisArmBeforeT is
> not a legitimate
> > instance.
> >
> > This is not the end of the argument since there are responses and
> > counter-responses to each of these points.
> >
> >
> > JOE'S ARM REVISITED
> ...........
>
> more interesting stuff, but I must break now. Thank you,
>
>
> --
> - - - - * * * * * - - - - * * * * * - - - - * * * * * - - - -
> Pierluigi Miraglia Cycorp, Inc.
> Ontological Engineer 3721 Executive Center Dr.
> (512) 514-2988 Austin, TX 78731
>