- From: Pat Hayes <phayes@ihmc.us>
- Date: Mon, 3 Mar 2008 12:37:04 -0600
- To: John Cowan <cowan@ccil.org>
- Cc: John Cowan <cowan@ccil.org>, "Booth, David (HP Software - Boston)" <dbooth@hp.com>, "www-tag@w3.org" <www-tag@w3.org>
- Message-Id: <p06230908c3f1eda399d6@[10.100.0.20]>
At 12:48 PM -0500 3/3/08, John Cowan wrote: >Pat Hayes scripsit: > >> And one can give many others, of course. But you are talking about >> essential properties - what in OntoClean are called, if memory >> serves, "rigid" properties. Whereas what David requires us to put in >> our declarations are "identifying" properties, those which are >> supposed to pin down a referent uniquely. These are not the same >> notion. Being human, as a property of a human, is necessary (rigid) >> but it is most emphatically not 'identifying' (until we get the point >> of there being only one of us around.) In fact, necessary properties >> tend to be of the least use for identification, precisely because, >> being necessary, they tend to be shared by everything else in the >> relevant category. If you want to identify me uniquely, you will do a >> lot better knowing my SS number (not essential or rigid in any way) >> than the essential fact that I am human. > >It's true that lots of essential properties aren't identifying in >themselves, but the more essential properties you know, the better a >job you can do at identification. (a) I see no reason why essential, as opposed to contingent, properties are important here, and (b) no matter how many you have, you can never get a single referent pinned down. > Because your SSN is not essential, >there may be another person who has the same SSN (such glitches are not >supposed to happen, but do). Or, more to the point, there may be another person who COULD have had my SSN. > Your DNA dump, though, *is* essential Why? Seems to me I could have had different DNA and still have been me. Its too late to change it now, of course. >, >and (given that you are not an identical twin) completely identifying. Indeed, it is identifying. > >We sometimes find it useful to treat non-essential properties like >name+DOB or SSN as identifying, but such treatments are always heuristic >in nature, always subject to being debunked thus: "No, I meant quite >a different James Earl Carter born on 1924-10-01." All 'identifying' descriptions are subject to correction like this. > >This can come up in real life. I once volunteered to help check >election records to identify a possible election fraud, and thought I had >found a hit -- but it turned out to be two sisters (or perhaps cousins) >living in the same house with identical first and last names (presumably >different middle names) and nearly indistinguishable signatures. A close >inspection showed that they had been signing each other's election >cards at random for years, but there was no actual fraud involved, >just a nearly inextricable confusion of identity. Nice example. I wonder if they ever got confused, themselves? > >> Overall, I'd suggest that this entire discussion is so hopelessly >> muddled that the proposal is best dropped before we generate even >> more confusion. At least, lets see some convincing examples of what >> might constitute an appropriate 'declaration' before proceeding. I >> don't think that "identifying properties" exist. Can anyone prove me >> wrong? > >As Quine says, there is no entity without identity, so if we wish to >drop identification, we will have a very difficult time distinguishing >things at all. Quine is referring to identity, not identification. All he meant was that you have to be able to make sense of equations: does A=B or not? Identification in the TAG sense is something altogether more than this: it means something social - having a kind of conceptual location in some social space of objects which can be "identified" - and it means being able to get from the 'identifier' to the thing it 'identifies'. None of this is in Quine. > If nothing else, it is identifying to say that object >o of sort s occupied space-time coordinates (x, y, z, t) relative to >some convenient origin. (I introduce "sort s" because although my liver >occupies some location at the present moment, I occupy it too.) You had better have a powerful (and universally agreed) set of 'sortal' descriptions available for all contingencies. Good luck with that project. (Was that liver-at-t a temporal slice of a 4-d liver-history? Or was it a liver-continuant, mentioned at a time?) And then you have to have some other way to handle the non-spatiotemporal entities such as abstractions of various kinds, Platonic things like numbers and symbols, psychological properties (where did I put that mood I was in?) and imaginary and fictional things. And in fact, I bet this wouldn't be considered a proper identifying description in David's sense, in practice. It would be pretty useless in a declaration. > >Quantum theory aside, we do not want to treat classical objects as if >they were cloudlets in a buttermilk sky, where it makes no sense to ask >"Is this one the same as that one?" Too much of logic and science goes >down the rabbit hole. I agree. Identity is a basic assumption underlying all of semantics. RDF and OWL already have identity built into their model theories, so we don't need anything new to have that. Tag:identification is something else again, however. Pat > >-- >Evolutionary psychology is the theory John Cowan >that men are nothing but horn-dogs, http://www.ccil.org/~cowan >and that women only want them for their money. cowan@ccil.org > --Susan McCarthy (adapted) -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32502 (850)291 0667 cell http://www.ihmc.us/users/phayes phayesAT-SIGNihmc.us http://www.flickr.com/pathayes/collections
Received on Monday, 3 March 2008 18:37:20 UTC