Re: facts of reality, context, possible worlds

re: facts of reality, context, possible worldsI've done a lot of snipping, and added a few comments prefixed with #####.
============ 
Dick McCullough 
knowledge := man do identify od existent done
knowledge haspart proposition list

  ----- Original Message ----- 
  From: pat hayes 
  To: Richard H. McCullough 
  Cc: RDF-Interest ; Richard S. Latimer 
  Sent: Friday, December 06, 2002 8:27 AM
  Subject: re: facts of reality, context, possible worlds
    1. RDF triples and facts of reality
    c. My response
    The purpose of the Semantic Web is to provide man and machine with easy access to the facts of reality.
  I would characterize it somewhat differently. The purpose of the SW is to make propositional content available to machine processing on the Web. Indeed, most of the time, that content will *correspond to* the facts of reality; but those facts themselves cannot be accessible to machines. One cannot send a fact over an optic fiber; one can only send symbols; a syntax of some kind. Now, exactly how a formal syntax can specify real facts is a good question: as I said above, getting that correspondence clear is what model-theoretic semantics is about.
  ##### Personally, I will be very disappointed if I cannot directly access RDFS/OWL Classes & Properties.
    2. context
            definition of rain
            definition of fall
  Most natural-kind terms like this do not have definitions.
  ##### My dictionary defines "rain" and "fall".


          3. possible worlds
    c. the KR alternative
    It is not necessary to pin down the actual world in full detail.  You can select the appropriate level of detail, depending on your purpose, and express it in KR propositions.
  Sure, so KR is a syntax, as I suspected. In which case it needs a semantics. Just saying that it 'corresponds to the facts' doesn't cut it.
  ##### "a syntax" and "corresponds to the facts" are your words, not mine.
  ##### KR is an English-like language with its own syntax and semantics.
  ##### The meaning of any KR proposition is the facts of reality which it denotes.
  ##### Consider the KR proposition
  #####    at view=tabula rasa {
  #####        Dick isa person;
  #####        Dick has sex=male
  #####    }
  ##### I think that the meaning of this proposition is immediately obvious 
  #####  to any English-speaking adult.
  ##### Although Knowledge Explorer (KE) does not "understand" this proposition 
  ##### in the same sense as a human, KE can "reason" effectively using its
  ##### internal entity-characteristic-proposition taxonomy.