SUO: Re: Finding an upper ontology

["John F. Sowa" <sowa@bestweb.net>]

Stephen,

Before discussing your note, I wanted to say that I
tried to download your Powerpoint slides, and only the
title slide was downloaded.  Was there some problem
with the file you posted on your web site?  If so,
could you please repost it and send us the URL?

In any case, I get the impression that your latest note
was written from a different point of view than I was
assuming.  I would be quite happy to talk in terms
of your terminology, but since I couldn't read your
slides, I'm not sure what terms you use.

In any case, I would agree that every notation is a
matter of convention.  The real issues are how that
notation relates to anything in the world and anything
that we might do or say about the world -- and most
importantly for what purpose.

What I was talking about below, is the top node of
a hierarchy of categories, which in my notation is a
synonym for the category which Aristotle called "to On"
(Being), some people label Thing, and I prefer to call
Entity.  The corresponding predicate is true of everything
that exists or can exist.  I said that it is "empty" because
it contains no meaning in itself.  It is universally true
of everything for the simple reason that it says nothing.

JFS> For starters, the only universal point we can all agree to
>    is a one-category ontology, which contains nothing but the
>    empty node at the top.  That is a start, but not a very
>    useful one.
> 
SD> By the 'empty node' do you mean 'nothing' or do you mean
 >   'the empty > set'? Nothing, as in the absence of a thing,
 >   or empty, as in a(n imaginary) container with no members?

I was speaking loosely.  To be precise, the top node of the
hierarchy is universally true of everything merely because
it says nothing about anything.  It is "empty" of meaning.

SD> We can have first principles if we wish, but first principles are not 
> matters of discovery, they are matters of agreement, and on some things 
> - even so simple as the characterization of nothing - there may not be 
> agreement, not, at least, if both parties to the discussion understand 
> what follows from such first principles.

I agree.  I was talking about a particular convention for drawing
the hierarchy of categories in an ontology.  It is purely converntional
and it does not impose any restriction on what choice of categories
one might place underneath the top.  The ones beneath the top are
the ones that actually have some significance.

> Experience is like a large jugsaw puzzle, all the pieces scatted on the 
> table in front of us. Some people insist that the only proper way to 
> start is with a corner piece. Others prefer to start at an edge. Others 
> prefer to find pieces of similar colour, or similar shape, and build 
> from within.

I have no objection.

> In jigsaws, this is no problem. In experience, if you start in one 
> place, you get one picture, and if you start in another place, you get 
> another picture. Which picture is 'correct'? There is no way to tell: 
> all we have is experience, and ways of putting it together.

There is an open ended number of pictures that one can draw for
an open ended number of different purposes.  I agree that there is
no way to compare picture A drawn for one purpose with picture B
drawn for a different purpose.

Example:  Consider a map of the United States that fits on a single
sheet of paper with a map of a single street in Chicago that shows
each individual house on the block.  Without knowing the purpose,
you cannot say that one is better than the other.

If your purpose is to relate Chicago to the rest of the US, the
first map is better.  But if you want to find a particular house
on that street in Chicago, the second map is better.

Value judgments about a representation always depend on purpose.

John Sowa