Subject: Re: SUO: Physical and Abstract From: "John F. Sowa" Date: Thu, 16 Oct 2003 09:29:50 -0400 To: Stefano Borgo CC: SUO , cg@cs.uah.edu, Nicola Guarino Stefano, I can't say that I have read every paper about Dolce, but I have read quite a few. And I have been discussing many of the disagreements I have with Nicola for many years before Dolce came to be. You and Nicola and your colleagues have a right to your opinions about how an ontology should be designed. I would be very happy to see Dolce adopted as a module in the SUO ontology, but I would not be happy to see it or any other ontology treated as a standard that has a privileged status over anything else. In any case, following are some comments on your coments: JS> That is one of my primary objections to DOLCE: They > put far too much emphasis on identity as something that > is supposed to be fundamental to ontology.... SB> When you combine ontology and logic, (absolute) identity > becomes an important element (since it is part and parcel > of the logic framework). That is an interesting point, but we have drawn different conclusions from the same observation: 1. The = symbol in predicate calculus or the dotted line in a conceptual graph indicates that two different logical expressions are intended to refer to the same entity within the context of a given statement or substatement. 2. The notion of "identity", which is sometimes associated with the = symbol, is a pretheoretical notion, which many people have used in many different ways. Before you can place an = symbol between two different epressions, a great deal of analysis must be done. 3. All the many books and articles that Nicola and I and many other people have read and written about identity indicate that it is an extremely problematical notion, which has no clear-cut answers that are definitive and acceptable to everybody for all purposes. 4. In short, identity is highly dependent on context and purpose. That does not mean it is a useless notion, but it does mean that you can't rely on two different people in two different situations to come to the same conclusions about it. For these reasons, I don't believe that identity should be taken as a primitive or a fundamental notion for the purpose of designing an ontology. As I said, identity is something to be explained rather than something that can be used to explain anything else. (And that way of making the point goes back much farther than Peirce -- Socrates was its principal exponent.) JS> ... They end up with multiplicities of individuals in > every space-time region depending on the whim of anybody > who happens to classify what they see. SB> I'm afraid your choice of words tends often to be > political more than scientific. No, I used the word "whim" to indicate my disapproval rather than my politics. But I admit that approval or disapproval are pretheoretical reasons -- that doesn't make them bad. SB> If there are properties that one wants to consider > and those seem contradictory if applied to the same > entity, one should consider distinguishing different > entities. Perhaps. But the example that is always used is "vase" vs. "lump of clay". Those are two different descriptions, but there is no contraction in applying them to the same "entity". Do you have any other examples for which there is a clear contradiction? SB> However, it seems that in applications what we suggest > is considered a good strategy. I agree that any analysis is better than no analysis, and just the act of sitting down and analyzing the requirements for an application is likely to lead to a better design. So I'm sure that you can find many successful examples of the Dolce approach, just as many other people have pointed to successful examples of their approaches. SB> We already had a discussion on your view of absolute > identity but at that time you could not be specific on the > notion of symmetry (which I surmise you equal to an equally > vague notion of relative identity) and I gave up considering > your approach. Do you have new thoughts about it? I'm interested > (at least formally) in these notions but I haven't seen any > promising approach. I remember some discussions, but I don't recall any specific issues or examples. And I certainly don't recall using the term "absolute identity". I may have said that having two different entities in the same space-timne location was a notion I found couterintuitive, odd, and not the usual way of using language either in science or in everyday speech. But I don't recall saying anything about symmetry. SB> Are Abstract and Physical the same as Universal and Particular > as Aristotle used them, or is the latter pair useful for > Aristotle but not useful now? Or is it just that you get > confused easily and so you ask everybody else to change notation? I wasn't complaining about Aristotle's use, since he was a pioneer in trying to develop a clear terminology for the subject. Since then, many other people have adopted those with many conflicting interpretations. Anybody who adopts those terms has to clear away many centuries of associations, many of which are misleading or not intended for the new way of using the terms. As a replacement, I was suggesting two terms Abstract and Physical, which I find easier to explain to more people. Furthermore, I find that every problem which Aristotle and others have been analyzing with the terms Universal and Particular can be analyzed and explained more simply with the terms Abstract and Physical. Therefore, there is no need for the old terms (except in a footnote for people who may be interested in following up the references). SB> I agree that it is very hard to understand the term > "abstract particular" in Dolce. The reason is that > "abstract particular" is NOT used in Dolce. > > "Particular" is a term used only on the metalevel, > it's not part of the ontology. "Abstract" occurs in > the taxonomy. "Abstract particular" is *never* used. I thought that I saw that term in some paper. If I am wrong, then I am happy to be corrected, and I am happy to see one less point of contention. SB> Those looking for perfection might be disappointed > by Dolce as well as by the work of Peirce, Jesus, > or Mohammed. Still, all these deserve to be treated fairly. I certainly agree. And to continue that point, if Dolce is just one more religion that we can put in the catalog, I have no objections. But I wouldn't want to treat it as a state religion that everybody must follow. John PS: I did have a problem downloading the following file: http://www.loa-cnr.it/Papers/WonderWebD17V2.0.pdf For some reason, it wouldn't download when I clicked on the URL. I don't know whether it is a problem with my software or a more general problem.