Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!uunet!tdatirv!sarima From: sarima@tdatirv.UUCP (Stanley Friesen) Newsgroups: comp.ai.philosophy Subject: Re: UNIFIED MODEL FOR KNOWLEDGE REPRESENTATION? (IMPOSSIBLE Message-ID: <54@tdatirv.UUCP> Date: 20 Jun 91 17:35:41 GMT References: <25348@samsung.samsung.com> <1991Jun14.111857.7374@kingston.ac.uk> <1991Jun19.103728.5004@tygra.Michigan.COM> Reply-To: sarima@tdatirv.UUCP (Stanley Friesen) Organization: Teradata Corp., Irvine Lines: 100 In article <1991Jun19.103728.5004@tygra.Michigan.COM> dave@tygra.Michigan.COM (David Conrad) writes: >In article <1991Jun14.111857.7374@kingston.ac.uk> is_s425@kingston.ac.uk (Hutchison C S) writes: >We're dealing with slippery slopes here; is a person who believes that there >are no intrinsic differences between ethnic groups and who is opposed to >affirmative action programs a racist? This is a question without a right >answer. Quite, and this is not even a rhetorical question - such people really do exist (I can name at least one). >>"unicorns, Sherlock Holmes" and such like exist; it just so happens that (so >>far as I am aware) they don't exist in the *actual* world. >Consult the publicly observable meaning of the word 'exist' in any convenient >dictionary; your use of it differs greatly from mine. I'm glad someone said this - this business of treating unicorns as existing in "some" world has always been a sticking point for me with regard to the "possible worlds" approach to meaning. [I would say that the word 'unicorn' refers to something that does not exist]. >>Finally, with regard to your last paragraph, if two people are never really >>talking about the same things, then they can never come to any agreement about >>the same things ... >As I've tried to point out in two previous postings, *one* person can never >be certain exactly what real object she is referring to, or even if there >*is* any real referent, so how could two people ever even hope to be >certain that they are discussing the same thing. However, people can >have degrees of certainty etc. And when the degree is so great that they >don't bother to worry about the case where they are talking about different >things, then yes, they do "behave *as though* they were talking about the >same things...." Indeed, and I can remember situations where I had a high degree of certainty that I knew what was being talked about where the other person disagreed and managed to convince me I was mistaken. >>But I rather think that to focus attention exclusively on "internal models" >>is to dodge the issue. The example I like is that of a filing cabinet. When >>I use the expression "filing cabinet" as a referring expression, ... >But aren't your "assumptions...about its functionality" part of your "internal >model of a filing cabinet"? Furthermore, my internal model is not "dependant >on the existence of filing cabinents ... 'out there' in the world." I can >have an internal model of all kinds of furniture just based on drawings and >descriptions of them. ... >But my main problem is with the idea that an internal model can be seperated >neatly into physical and functional components. I doubt that it is possible >to think about the form of a filing cabinet without its function being also >summoned to mind. I believe that the form and function of objects are >connected in mental models of them. And even more. When I hear or say 'filing cabinet' I usually *start* with a mental image of my own filing cabinet sitting in a corner at home and .... I find that all of these diminishing associations are intrinsically bound up in my mental model of filing cabinets. >>Now back to my "rioting blacks"/"racists"/& cet problem. I assume there is a >>real world out there in which things like "riots", "police", "racists", and so >>on, are possible objects. The question again is: are reports of events which >>include such terms capable of being true or false? (I think they are.) If >>so, how can conflicting reports be true at the same time? Otherwise, if >>not, why not? >How many people acting violently make up a riot? How sever/general must a >persons feelings about race be to make a racist? These are slippery slopes, >subject to personal interpretation. Your rioter may be my protester, or >vice versa, and only statements which can be interpreted the same by all >can be classified definatively as true or false. You think that reports >containing highly subjective statements are capable of absolute truth or >falsehood, I do not. [And now for the meat]. I think this is really the core of the issue. Almost all of these terms are subject to individual interpretation. For instance the term 'rebel' may have different referents depending on who is speaking - I see the definition as being: "Someone in violent opposition to duly constituted authority". This makes the term relative to who the speaker considers to be 'duly constituted authority'. This is a matter for intense disagreement. [In the Middle Ages there were two Popes for about a century - the followers of each considered the other's followers to be rebels - and even today it is not entirely clear which one was the proper Pope]. So, as to the hadlines quoted, I would say that for all *practical* purposes they were *all*, in some basic sense, "true". That is I can come up with an internal model of events and participants such that various different observers might *honestly* make all of the statements listed. (That is the statements would match the definitions in current use by the individual uttering them). I think this approach - a sort of contingent, model based approach to validity (so-called truth) - is a much more useful than trying to apply a mathematical/logical deductive definition of 'true'. -- --------------- uunet!tdatirv!sarima (Stanley Friesen)