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? 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.
> 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?
(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 -- 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). Instead we
have 2 parts of a peculiar type of thing that is never fully there at any
particular time. Do I understand correctly?
......
> 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.
> 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,
--
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Pierluigi Miraglia Cycorp, Inc.
Ontological Engineer 3721 Executive Center Dr.
(512) 514-2988 Austin, TX 78731