RE: SUO: Set/Class Distinction
Dear John,
It isn't that what you say below is wrong, but it seems to me
a view of 4D starting from a 3D perspective.
I would say that there is a 4D "worm" that is John Sowa, and that
this intersects with the 4D worms of other objects. For example,
there is the 4D worm of an oxygen atom you breath in. It is
incorporated into your body for a period, and is eventually
exhaled as carbon dioxide. As result, there is a sub-state of the
oxygen atom that is a part of you. Equally, there is a state of you
of which the oxygen atom is a part.
The difference in perspective is subtle. Your description reads like
the frames in a film being sewn together. Mine emphasises the
continuity of which there are parts.
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: John F. Sowa [mailto:sowa@bestweb.net]
> Sent: 18 September 2001 01:43
> To: Patrick Cassidy
> Cc: Ian Niles; Standard-Upper-Ontology (E-mail); phayes@ai.uwf.edu
> Subject: Re: SUO: Set/Class Distinction
>
>
>
> Pat and Ian,
>
> This is another issue where the abstract mathematical notions
> bump into the per- and en- issues, which are usually associated
> with physical entities.
>
> Patrick Cassidy wrote:
>
> > I thought that one of the distinctions was that
> > sets are necessarily defined extensionally, whereas
> > a Class may have a membership criterion such that
> > the same class may have different members at
> > different times. Is this a misunderstanding of what
> > the present definitions mean?
>
> Whatever set of conventions are adopted for physical entities
> should be compatible with the conventions adopted for mathematical
> entities. Every time I take a breath, I lose or gain molecules.
> Does that mean that I am a different physical entity at each
> moment?
>
> Following is a brief summary of Whitehead's position about
> physical entities:
>
> 1. He reserves the term "actual entity" for something that
> exists for only a very short duration of time (for the
> length of whatever the shortest measurable interval is in
> the granularity that is being used for some application).
>
> 2. Each actual entity perishes at the end of each moment,
> to be replaced by a new actual entity at the next moment.
> So at each moment, there is a new actual entity that has
> the same name and most, but not all of the same molecules.
>
> 3. The time-extended collection of all the actual entities
> named John Sowa form a "nexus", which consists of all the
> embodiments of that person at different moments throughout
> his life.
>
> 4. A similar solution could be adopted for any other kind of
> structure. You could talk about a time-ordered sequence
> of sets, which all had the same name S. But S would actually
> be a function from times to sets; i.e., S(t) would be the set
> of entities at time t.
>
> John Sowa
>