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RE: OWL 2.0 ...

From: Lansing, Jeff <jlansing@systechnologies.com>
Date: Fri, 15 Apr 2005 08:12:44 -0700
Message-ID: <0924D8C9ADE6C04D9FA73CC47C0FA8E401250407@SYSSDEX.syys.com>
To: "Hans Teijgeler" <hans.teijgeler@quicknet.nl>, <public-owl-dev@w3.org>
Cc: "Matthew West" <matthew.west@shell.com>, "Valen-Sendstad, Magne" <magne.valen-sendstad@dnv.com>

Not to be unkind, but this response strikes me as being, rather than "exquisitely ontological", more like "exquisitely ontologically naive".
Let me start by posing a few questions motivated by the exerpt from the book.
Are there things? (If the answer is "obviously yes", then why the popularity of idealism?)
In what sense of 'inside' is the essence (whatever *that* is) "remain[ing] inside things even when they change"? (Do all things have these little shells that hold their "insides"? What about the North Pole and The Equator -- which are claimed below to "exist in real space"? Do they have "insides"?)
Do concepts (book, table, tree, etc.) even exist *inside* our mind? (As far as I can tell, that's still an open question. See eg., 'The Big Book of Concepts' by Gregory Murphy, for extended discussion.)
Is it even coherent to say at the same time that "we can distinguish between essence and existence" and that "an existence is to be present among things in the real world"? (Presumably the intent is that an essence is not "present among things in the real world". But then how can essences be inside things without being present among them?)
I'm just skimming the surface here to point out what are apparently some unquestioned assumptions. But that's not to say that it's not possible to do ontology engineering in an informed way. For example, the GOL work seems to me to be very carefully thought through.


From: public-owl-dev-request@w3.org on behalf of Hans Teijgeler
Sent: Fri 4/15/2005 3:25 AM
To: public-owl-dev@w3.org
Cc: Matthew West; Valen-Sendstad, Magne
Subject: RE: OWL 2.0 ...

Let me start with an excerpt from the book "Ontological Engineering" by Asunción Goméz-Peréz, Mariano Fernández-Lopéz, and Oscar Corcho:
What are things? What is the essence that remains inside things even when they change (changes in their color, changes in their size, etc)? Do concepts (book, tree, table, etc) exist outside our mind? How can the entities of the world be classified? These are some of the questions that Ontology, the philosophy of being, has tried to answer for thousands of years. In Ontology we can distinguish between essence and existence.The essence of something is what this something is. However, an existence is to be present among things in the real world. For instance, a centaur is half a man and half a horse, so it has essence though it does not exist.

You wrote:
<PM> This strikes me as an exquisitely ontological, or if you prefer domain-sensitive, determination
<HT> The data model of ISO 15926-2 is as generic as it can be and is NOT domain-specific. The domain-specific aspects are introduced when linking it to a particular vocabulary (we call it a Reference Data Library). If the library is about medical classes, the information is about medical matters, if the library is about real estate stuff, it is real-estate information. How much more generic can you be? And what is wrong, in the context of OWL, with being "exquisitely ontological"?
<PM> There are plenty of individuals (in the sense in which individuals are in pricniple distinct from classes) that would not have spatio temporal presence such as you describe. 
<HT> In our, and the above, meaning of "individual" ALL have spatio-temporal presence. It is a matter of definition and paradigm. 
<PM> There can be abstract individuals that have no particular location, though perhaps a "lifetime": ordinary examples would be, under plausible assumptions, Beethoven's 5th symphony and the "Crusoe." 
<HT> This proves my point: you don't make a difference between Beethoven's 5th Symphony as (in our terminology) a class_of_activity and as an activity. The latter happens at a particular evening in, say, the Scala of Milano, and is a member of the class_of_activity "Beethoven's 5th Symphony", together with all the other performances in the past, present, and future.
<PM> There can be individuals that have perhaps location in abstract space, but no lifetime: the Equator, or the North Pole.  All this might be in dispute, of course.  
<HT> The North Pole and the Equator exist in real space. I don't think that Robert Peary's expedition in 1909 travelled to something that was in abstract space. In our definition the North Pole is a spatio-temporal individual that is a "feature" of the globe (like a nose is a feature of a face), and it is classified with a class that has certain criteria for being a North Pole (mind you, the North Pole isn't at the same location all the time).

<PM> The point is I don't think this belongs in a language's specification. 
<HT> Not if you deliberately want to limit the expressivity of that language.
Hans Teijgeler
co-author of ISO 15926-2 <http://www.infowebml.ws/ECM4.5/ECM4.5.html> 
author of ISO 15926-7
website www.InfowebML.ws <http://www.infowebml.ws/> 
e-mail hans.teijgeler@quicknet.nl
phone +31-72-509 2005                     

Received on Friday, 15 April 2005 15:52:18 UTC

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