Re: Which ontologies; how to compare them

Don Dwiggins <>
Subject: Re: Which ontologies; how to compare them
Date: Thu, 17 Feb 1994 16:05:39 -0800 (PST)
From: Don Dwiggins <>
Cc:, interlingua@ISI.EDU, srkb-list@ISI.EDU
In-reply-to: <> from "Fritz Lehmann" at Feb 17, 94 06:37:46 am
X-Mailer: ELM [version 2.4 PL23]
Content-Type: text
Content-Length: 2348      
Message-id: <>
Fritz Lehmann writes, in reponse to Roberto Poli:
> >>I don't understand 'internal relations'.
> >It is an old distinction. It could perhaps be rewritten saying that an
> >internal relation is a relation of mutual existential dependence. Consider
> >the connection teacher/pupil. There is no teacher if there is no pupil (and
> >viceversa). It is important to note the following aspect: we can say that
> >someone is a teacher even if s/he doen't have any pupil, but in this case we
> >say that it is a potential teacher, not an actual one. Consider now the
> >lenght/breadth opposition. No thing has lenght without having also some
> >breadth (and viceversa). We can build up things that have only lenght and
> >no breadth, but such things are ideal things, not real ones (if you prefer:
> >abstract, not concrete things). You see from the
> >above example that at least some internal relations are useful in
> >distinguishing real things from ideal things and real actual things from
> >things that are only potential. From these skratched examples you see that
> >internal relations (or double existential dependence relations) play a deep
> >role in the organization of a conceptual network. What is quite strange to
> >our scientific taste is that the topic of internal relation was the pi!ce de
> >r!sistance of the so-called idealists philosophers. For this reason, the
> >choice to exclude idealists thinkers (say Hegel) from your list could be
> >(at least in part) unjustified.
>      This symmetric internal/external "foundation"-like thing
> sounds useful  -- OK, so maybe my gut feelings are wrong about
> Hegel, but please, don't ask people to read him!  I hear he's as
> bad as late Husserl.  For these Tedeschi we need interpreters like
> you who are willing to give simple examples.  (So do their fellow-
> Tedeschi, I bet.)

It is useful.  In the relational database community, this concept (or one
much like it) is called "referential integrity"; it's usually illustrated by
examples like "you can't delete a customer if there are outstanding invoices
to him".  I'm only tangentially involved with RDBs, so I don't have any good
references beyond the standard textbooks like Date.

Don Dwiggins				"The truth will make you free,
Mark V Systems, Inc.			 but first it will make you miserable"				 -- Tom DeMarco