- From: pat hayes <phayes@ihmc.us>
- Date: Mon, 29 Sep 2003 10:26:01 -0500
- To: "LYNN,JAMES (HP-USA,ex1)" <james.lynn@hp.com>
- Cc: public-sw-meaning@w3.org
>So would it be useful to have, as a convenience, some kind of >"owl:intensionsl" attribute? No, because OWL (unlike RDFS) is entirely based on an extensional (non-intensional) semantics. So it would be kind of meaningless in OWL. BTW, if this answer makes you feel like tearing your hear out, join the club. Pat > >> -----Original Message----- >> From: pat hayes [mailto:phayes@ihmc.us] >> Sent: Friday, September 26, 2003 8:42 PM >> To: LYNN,JAMES (HP-USA,ex1) >> Cc: public-sw-meaning@w3.org >> Subject: RE: 'all resources' is not a set >> >> >> >-----Original Message----- >> >From: pat hayes [mailto:phayes@ihmc.us] >> >Sent: Thursday, September 25, 2003 7:31 PM >> >To: Larry Masinter >> >Cc: public-sw-meaning@w3.org >> >Subject: Re: 'all resources' is not a set >> > >> > >> > >> >>> Is the referent of >> >>> 'the morning star' and of 'the evening star' the same? >> >>> Not defined. >> > >> >> You chose a very bad example to make your case. The whole point of >> >> the example is that it IS well-defined: the answer is yes, they do >> >> have the same referent, viz. the planet Venus (but some >> people don't >> >> know that, hence the point of the example.) >> > >> >I may be a little unclear on how 'referent' is being used. >> If the term >> >infers 'the actual object', as in Venus, I guess it's pretty clear. >> >> Yes, that was the original idea of the example. BUt I agree you can >> say that there are two intensional things which happen to have the >> same extension, so that there are three distinct 'ideas' involved. If >> you wanted to have an ontology about ideas rather than astronomy, >> that would make sense. Either way, however, you can use set theory >> as a foundation. In fact, you can have both ways of thinking and >> still use set theory, as long as you keep the various ideas clear. >> >> >Perhaps >> >a better example of what confuses me is my congressman. My >> intent is to >> >assert something about the representative like "he is >> accountable for X", by >> >virtue of his role as a representative. In this case I don't >> care that at >> >the moment my congressman is John Smith, since next year my >> congressman may >> >be Jane Doe. But my assertion still stands. Is this notion >> of role different >> >from the Venus example? >> >> There are lots of examples like this: "The President" (who can change >> from one guy to another every now and then, but is always The >> President), or even things like "the main engine" which might be a >> different piece of machinery after an overhaul but is still the main >> engine. You can take various positions on what 'things' like this >> really are and how to best describe them, but they pose no particular >> challenge to set theory as a foundation. For example, you can invent >> a category of functional entities, and say that at any given time, a >> functional entity is identical to a unique physical entity, but the >> correspondence might change at various times. (Often, the times or >> events have a special status, eg service outage or inauguration) . Or >> you can invoke an overriding theory of 'continuants' or 'histories' >> or 'eventualities' and base your ontology on those. But again, all >> of this can be accommodated within a set-theory foundation: in fact, >> all of these have been used in first-order logic-based ontologies. >> >> One way to conflate intermittent things like this to the Venus kind >> of case is to use intensional individuals everywhere. What that means >> in practice, however, is that you often need to say explicitly that >> lots of normal things aren't particularly intensional and don't >> change every now and then; and since there are often more of these >> normal things than the other kind, it is usually easier to treat the >> odd ones as oddities. >> >> Pat >> >> >James Lynn >> >Strategic Coordination - Enterprise Standards >> >HP Software Services >> >610 595 4995 >> >> >> -- >> --------------------------------------------------------------------- > > IHMC (850)434 8903 or (650)494 3973 home >> 40 South Alcaniz St. (850)202 4416 office >> Pensacola (850)202 4440 fax >> FL 32501 (850)291 0667 cell >> phayes@ihmc.us http://www.ihmc.us/users/phayes >> -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32501 (850)291 0667 cell phayes@ihmc.us http://www.ihmc.us/users/phayes
Received on Monday, 29 September 2003 11:26:02 UTC