Re: SUO: RE: A proposed SUO content outline
> >
> > MW: What you will see from this is that your ontology
> > (although in this case
> > both convey the same information) actually determines what
> > objects exist,
> > and also therefore what classes you are interested in. All
> > four objects in
> > the continuant/occurrent ontology get merged into one object in a 4D
> > ontology (there are cases where there can be more 4D objects than 3D
> > objects).
> >
> > MW: Now I can write down the rules for converting from one
> > ontology to the
> > other, but if I try to combine the two I just get nonsense,
> > because there is
> > a basic conflict between the ontologies about what objects exist.
>
>I guess part of what you are arguing here is that the 4D orientation brings
>about an overall decrease of theoretical complexity as compared with the
>conventional 3D way of looking at things.
And what, pray, is the 'conventional' way of looking at things? Like
many endurantists, you seem to have a deep inner conviction that
human beings are born with your philosophy built into their nervous
systems. For myself, I have thought of things in 4-d terms since I
was a child (though I wouldnt have *described* it that way at the
time.) In fact, I think that most people do, even when they don't
like that way of talking. Don't you think it is 'conventional' to
think of a thing as lasting through time?
>I guess too that I just don't
>agree. Although, as you say, the 4D scheme says that there is just one
>object, viz. the space-time worm, while the 3D scheme says that there are
>four things and a host of relations among these things, it seems to me that
>complexity soon creeps into the 4D orientation.
The complexity is there in the world; the issue is how to most
usefully describe it (or the parts of it that need describing).
>For, on this scheme, we are
>required to have rules for individuating the vase/clay space-time worm from
>the whole space-time worm that surrounds it and rules for slicing space-time
>worms into what are conventionally regarded as stuffs and objects. Without
>these individuating and slicing rules, we won't be able to talk about these
>stuffs and objects, and then, well, we won't have much to talk about.
There is a simple, universal, criterion of identity: spatiotemporal
things are individuated by their spatiotemporal extensions. The rules
for slicing and containment of one worm in another are universal and
apply to all worms. Moreover they are quite obvious and transparent,
being simply the 4-d generalisations of the familiar notions of
slicing, containment and projection from 3- and 2-d geometry (and
since most of the extant ontologies for things like mereology in fact
do not refer explicitly to dimension, they apply *without change* to
worms.) So all of what might be called the apparatus with which to
state more subtle individuation criteria come for free. (You still
need to actually state them, in any reasonably complete ontological
framework, of course.)
BTW, you mention 'stuff'. Good point. Take an example of 'stuff', eg
say stainless steel (SS). The mereological perspective says that what
this means is the mereosum of all pieces of SS in the universe. Seems
to me that this had better include all the pieces in the past, and
probably the future, as well, wouldn't it? If not - if we take the
endurantist position that 'all pieces' means 'all pieces now' - then
every piece of stainless steel is kind of losing its own history,
since if it is SS at time t then it ceases to be SS when seen from
time t+1, since that 'piece' is then - at time t+1 - in the past, so
not part of an endurantist's mereosum. So for example my liver is
made of liver-stuff, and my liver yesterday was made of liver-stuff
yesterday, but it's not made of liver-stuff now, on this view, since
"liver-stuff" is only the stuff in the present. What do I (now) say
it was made of? Ex-liver-stuff?
>Furthermore, as I've mentioned before, I think as much as possible we should
>steer clear of questions about what *really* exists. As I've repeated (ad
>nauseum at this point), we're not doing philosophy here; we're constructing
>an engineering artifact. As long as the ontology permits us to say what we
>want to say in a formally specified manner and as long as it permits us to
>substantially ease information-sharing among different automated systems, we
>will have done our job.
Quite. Please stop saying this, Ian; we all agree on this. The
motivation for the 4-d ontology is not some philosophical position on
the intrinsic 4-d nature of Reality, but the hard practice of trying
to say what we want to say. That is why I was obliged to use a 4-d
ontology in my old ontology of liquids: it just couldn't be done in
terms of time-indexed 3-d entities. That is why it is used throughout
qualitative physics, and why Matthew has moved to it under pressure
of the engineering requirements of the oil industry.
Pat Hayes
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