On Jan 27, 2011, at 2:38 PM, Chris Partridge wrote:
> ...
> BTW the oddity I find with the Markosian description is this - "By
> contrast, on The 3D View, objects are to be thought of as three-
> dimensional things that are not made up of different temporal parts. (01)
This seems a good description of the 3D View. In the 3D View an object
has a starting time and an ending time, and the object can be referred
to as the same object at any time it exists. Translated into 4D terms,
the 3D View labels a certain set of 4D worms as objects but does not
include the concept of temporal parts or slices of the worm. (02)
Attributes which the 4D View assigns to a slice of a temporal worm
applies to the whole object *at the specified time* in the 3D View. (03)
> On this view, an object at a time (04)
... is not considered as an object or as something with an identity.
This is the concept of a temporal slice. (05)
> - Descartes in 1625, for example - is the same thing as the whole
> object - Descartes. (06)
This is an incorrect portrayal of the 3D View, as the 3D View does not
include the first object. Instead of saying, "Descartes in 1625 is the
same thing as Descartes", the 3D statement would be "in 1625 Descartes is
the same thing as Descartes." In 4D terms, this would mean "a 1625
temporal slice of Descartes is a temporal slice of Descartes." (07)
Some 3D systems do not allow a comparison of things at different times. (08)
> Thus, according to The 3D View, the relation between
> Descartes in 1625 and Descartes in 1635 is the relation of identity:
> each one is just the same thing as Descartes." (09)
They are "identical" in that the two references to Descartes have the
same "identity", in the 3D View. There is no "each one", since only
one object (in 4D terms, a temporal worm) referred to. (010)
> As a term, 3D or three-dimensional things seems to imply spatial
> dimensions, but 'Descartes in 1625' and 'Descartes in 1635'
> are identical, (011)
No. The 3D View does not have the concept of "X in Year Y". This
could be stated in 3D terms as "the person referred to as 'Descartes'
in 1625 and the person referred to as 'Descartes' in 1635 were the
same person." (012)
A feature attributed to a temporal object at a certain time in the
3D view, should be translated into a 4D statement saying that a
temporal slice of that object has that property at that time. (013)
> and he had a wider girth in 1635
> (or was in a different part of the house/country), then
> spatially he does not seem to be identical (014)
The identity is for the object -- in 4D terms the temporal worm --
not for any arbitrary property of the object. (015)
> - his spatial characteristics (his 3D characteristics?) are then
> clearly not identical. (016)
Features of a temporal spatial object are permitted to be different
at different times in a 3D View. (017)
> But Markosian says
> "on The 3D View, objects are to be thought of as three-dimensional
> things". (018)
They are thought to have 3 spatial dimensions, and also a temporal
extent -- which is not thought of as a dimension. (019)
> How can we think of them 'three-dimensional things' and also identical at
> different times? (020)
Some 3D systems would not allow the comparison of an object at different
times. For systems that do, such objects would be identical in that they
have the same identity -- not in that they have the same properties at
different times. (021)
> What sense does three-dimensional have here? Does it just
> mean capable of having spatial dimensions? (022)
It would mean having three spatial dimensions. (023)
> Your question, which to me has almost the force of a plea,
> is exactly my own reaction to
> the 'continuant' notion which Markosian is describing here.
> But this really is what some philosophers
> (Barry Smith and Peter Simons, to name
> but two) insist upon: ordinary physical objects,
> such as cups and saucers and animals such as you and me,
> are genuinely three-dimensional things which
> last through time (024)
In 4D terms, they are referring to 4D worms. (025)
> (already I have a mental problem, but leave that aside)
> and change their physical properties (perhaps) but not their identity.
> You are the *very same person* as time passes, on this view,
> and yet you are three-dimensional: (026)
... in the spatial sense of "dimensional". The 3D view certainly accepts
that a temporal object has a start & end time. (027)
> at any time you are present, you are *wholly* present:
> all your parts are present. (Of course, by 'parts' I mean
> 'parts at the time in question',
> since parthood, like all other time-dependent relations, has
> to be relativized to a time.) (028)
This seems like a reasonable description of that view. (029)
> This perspective, I find, can be made
> intuitive and even comfortable, once one gets used to it;
> but it takes a certain mental discipline to keep reminding
> oneself that identity across times does not imply preservation
> of properties across times. I can grow fatter and still be the
> *very same* person, and this person can be wholly present now
> and also have been wholly present a while ago when I was thinner.
> Calling this 3D does not of course mean that I occupied the same,
> or even a congruent, chunk of 3D space as I did then; only that
> I did, and now also do, occupy a purely 3D space. And that space
> contains *all* of me now, just as that other space did back then,
> when there was less of me. (030)
This describes the 3D Viewpoint. However, it appears that you are
thinking of these 3D concepts in a 4D way, which makes it invalid. (031)
"All" of you refers to your complete 3D extent, not complete 4D
extent, above. Translating into 4D terms, the above description
means:
"A later temporal slice of me may be fatter than my current temporal
slice and still be temporal slices of the *very same* person, and
a temporal slice of this person can have its 3D extent wholly present
now and also have a temporal slice whose 3D extent was wholly present
a while ago when I was thinner. (032)
Calling this 3D does not of course mean that a temporal slice of me
occupied the same, or even a congruent, chunk of 3D space as a temporal
slice of me did then; only that a temporal slice of me did, and now
a temporal slice of me does, spatially occupy a purely 3D space. And
that space contains *all* of the 3D extent of my current instantaneous
temporal slice, just as that other space did back then,
when there was less 3D extent of the then current temporal slice of me." (033)
> But as I say, to stay comfortable with this perspective is a constant
> mental
> effort. And it has some very odd consequences. If for example we allow
> (as OBO does) something to be described either in this way or as a
> genuinely 4D entity, then we are obliged to distinguish the 4D 'thing'
> from the 3D one that lasts through time.
> OBO distinguishes in this way between a
> continuant and the occurrent which is that continuant's 'life'.
> So if Joe goes into an empty room and stays there for an hour,
> there were *two* things in the room during the hour: (034)
And for portions of the hour there were shorter slices of Joe's
lifetime. There were an infinite number of slices of Joe's life
in the room at some point during the hour. (035)
> Joe, the continuant, *and* the hour-long slice of Joe's
> lifetime. ( I have checked this very example with Werner,
> and he says this is the right analysis.) But of course they are
> in the room with two different senses of 'in', which makes
> everything much clearer. (036)
And the infinite other slices of Joe's lifetime are in the room
with a different sense of the word 'in'. (037)
-- doug (038)
> Pat (039)
> I would have thought something like "on The 3D View, objects are to be
> thought of as having a three-dimensional spatial extent with no temporal
> extent that can be different at different times" would be less confusing. (040)
> Regards,
>
> Chris
>
>
>
>
>
> From: Christopher Menzel [mailto:cmenzel@xxxxxxxx]
> Sent: 27 January 2011 19:32
> To: [ontolog-forum]
> Cc: mail@xxxxxxxxxxxxxxxxxx
> Subject: Re: [ontolog-forum] Presentism (was Re: Ontology of Rough Sets)
>
>
>
> On Jan 27, 2011, at 12:58 PM, Chris Partridge wrote:
>
> Hi Chris,
>
>
>
> Is the issue here *strict* presentism?
>
> (Where weak presentism would allow past and future objects to exist, but
> exist in different ways.)
>
>
>
> No. The qualification "strict" adds nothing; I should have just said
> "presentist".
>
>
>
> I was under the impression that presentism and standard 3D accounts fitted
> naturally together (for example, Markosian makes this point in the
> Stanford
> article, though I find some of his comments on 3D a bit odd.).
>
>
>
> I think Markosian's point is simply that one must be a 3D'ist if one is a
> presentist, pretty much by definition. But one can certainly be a 3D'ist
> without being a presentist. Presentism is a very problematic (though, I
> admit, rather metaphysically appealing, for whatever that's worth) form of
> 3D'ism - see for example the three difficulties Markosian mentions briefly
> at the end of the section on presentism in his article.
>
>
>
>
>
>
> That one of the attractions of a 3D view is that it supports a presentist
> stance.
>
> Otherwise, I cannot make sense of your comment - copied below.
>
> CM> This is actually a rather radical metaphysical doctrine that
> encounters
> very serious semantic roadblocks not encountered by the standard 3D and 4D
> views.
>
>
>
> It seems pretty clear to me that non-presentist 3D'ism is the
> "commonsense"
> view, at least, when it comes to the past - Socrates "exists in the past"
> and we unproblematically refer to him. For the presentist, this is
> strictly
> false, as there is no such ontological property as "past existence" and
> hence no such thing as Socrates to refer to. But how, then, do we make
> any
> sense of such apparently unproblematic commonsense truths as "Socrates was
> a
> Greek philosopher"?
>
>
>
> Presentism, by my lights, as an utter non-starter for the purposes of
> knowledge representation. There might be tortured ways for the presentist
> to make sense of claims about past and future entities, but if we're
> interested in building usable knowledge bases for information systems,
> regardless of where we come down on the 3D-vs-4D issue, we simply need to
> be
> "ontologically promiscuous" (to borrow from the title of a lovely (and
> important) paper by Jerry Hobbs) about past and future objects and refer
> to
> them and quantify over them liberally and unabashedly.
>
>
>
> -chris
>
>
>
>
>
> From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx
> [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Christopher
> Menzel
> Sent: 27 January 2011 18:31
> To: [ontolog-forum]
> Subject: Re: [ontolog-forum] Presentism (was Re: Ontology of Rough Sets)
>
>
>
> On Jan 27, 2011, at 7:00 AM, Ronald Stamper wrote:
>
> The only things deemed to exist in a presentist ontology (metaphysical
> sense) exist now. The present is no prison because we now have signs that
> stand for things we wish to know about in the past and future.
>
>
>
> Actually, for the strict presentist, that is flatly false, because there
> are
> no "things.in the past and future" for our signs to refer to and for us to
> know about, for only presently existing things exist and things only exist
> now. This is actually a rather radical metaphysical doctrine that
> encounters very serious semantic roadblocks not encountered by the
> standard
> 3D and 4D views.
>
>
>
>
>
>
>
> Presentism, I contend, provides a valuable discipline for engineers of
> information systems because that's the kind of world we deal with.
>
>
>
> Seems to me that the world we deal with is the same regardless of one's
> metaphysical take on time. Be that as it may, might I suggest that the
> view
> you are actually arguing for is not presentism but rather the standard
> (and,
> I think most would agree, commonsense) 3-dimensionalist view that there is
> a
> distinguished, objective, ever changing present in virtue of which things
> are (at any present moment) genuinely present, past, or future?
>
>
>
> Chris Menzel
>
>
>
>
> _________________________________________________________________
> Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
> Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
> Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
> Shared Files: http://ontolog.cim3.net/file/
> Community Wiki: http://ontolog.cim3.net/wiki/
> To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
> To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx
>
>
>
>
> _________________________________________________________________
> Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
> Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
> Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
> Shared Files: http://ontolog.cim3.net/file/
> Community Wiki: http://ontolog.cim3.net/wiki/
> To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
> To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx
>
>
>
> ------------------------------------------------------------
>
> IHMC (850)434 8903 or (650)494 3973
>
> 40 South Alcaniz St. (850)202 4416 office
>
> Pensacola (850)202 4440 fax
>
> FL 32502 (850)291 0667 mobile
>
> phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes
>
>
>
>
>
>
>
>
>
>
>
>
> _________________________________________________________________
> Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
> Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
> Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
> Shared Files: http://ontolog.cim3.net/file/
> Community Wiki: http://ontolog.cim3.net/wiki/
> To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
> To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx
> (041)
=============================================================
doug foxvog doug@xxxxxxxxxx http://ProgressiveAustin.org (042)
"I speak as an American to the leaders of my own nation. The great
initiative in this war is ours. The initiative to stop it must be ours."
- Dr. Martin Luther King Jr.
============================================================= (043)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/
To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx (044)
|