On Aug 12, 2009, at 4:37 AM, ingvar_johansson wrote: (01)
> Dear Pat H,
>
> You wrote to Chris P:
>
>> Of course I do not deny that. I was assuming a distinction between
>> 3-D-
>> ism and presentism, which you apparently conflate, but that is just a
>> matter of terminology.
>
> Can you please tell how you define '3-D-ism' and 'presentism',
> respectively.
> (02)
Sorry. Presentism is the view that only the present is real, so that
when we say 'exists' we mean, exists *now*. Tenses are used to refer
to the past and future, which are therefore thought of as 'alternative
worlds'. (To a strict presentist, in fact, these are in a sense
imaginary worlds.) But worlds, in this view, are inherently 3- rather
then 4-dimensional. When formalized, of course, this yields axioms
which change as time passes, a phenomenon which the presentist regards
as natural and even inevitable, on the grounds that time *is* change.
Much of ordinary language seems to presume a presentist conceptual
framework: we informally say things like 'Julius Caesar is no more' ,
meaning he does not exist *in the present*, and of course we use
tenses in the same way. The presentist of course sees the world as
being 3-dimensional, and typically mentions time, if at all, only
indirectly. (03)
What I was calling 3D in these discussions, but perhaps should have
been calling 3.1D, is a view that accepts the idea of time as
extended, and the need to refer to things in the past and the future,
but resists the idea that 'solid' things like people and objects are
truly 4-dimensional. It retains the 'presentist' view that a human
being, for example, is truly a 3-dimensional entity (the relevant
mantra is that all its parts are present whenever it is present, ie it
has no temporal parts, such as a childhood in the case of a person)
but asserts that this 3D thing 'continues' through time, hence the use
of the word "continuant". Note, this does not mean that it is
*extended* in time. There are things which extend in time, on this
ontological view, but they are inherently different from continuants,
more event-like, and are called occurrents. The occurrent/continuant
dichotomy is fundamental to these ontologies and colors their entire
approach: different ways of talking have to be used to refer to them,
and their relationships are carefully delineated. In contrast, what
are called 4D ontologies treat all physical things as occupying some
piece of space/time and (in the case of extensionalist versions, as
used by Chris and Matthew and indeed by me) individuated by their
spatiotemporal locations. Proponents of the 3.1D style of description
tend to characterize 4D ontologies by saying that they treat all
things as occurrents, which is kind of true but ontologically
misleading. It would be better to say that they deny the distinction
in the first place. (04)
Hope this helps. (05)
Pat (06)
> Ingvar J
>
>
> _________________________________________________________________
> Message Archives: http://ontolog.cim3.net/forum/uom-ontology-std/
> Subscribe: mailto:uom-ontology-std-join@xxxxxxxxxxxxxxxx
> Config/Unsubscribe: http://ontolog.cim3.net/mailman/listinfo/uom-ontology-std/
> Shared Files: http://ontolog.cim3.net/file/work/UoM/
> Wiki: http://ontolog.cim3.net/cgi-bin/wiki.pl?UoM_Ontology_Standard
>
> (07)
------------------------------------------------------------
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 (08)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/uom-ontology-std/
Subscribe: mailto:uom-ontology-std-join@xxxxxxxxxxxxxxxx
Config/Unsubscribe: http://ontolog.cim3.net/mailman/listinfo/uom-ontology-std/
Shared Files: http://ontolog.cim3.net/file/work/UoM/
Wiki: http://ontolog.cim3.net/cgi-bin/wiki.pl?UoM_Ontology_Standard (09)
|