Doug, (01)
That debate about the War of 1812 is a good summary of the
complexity of describing anything at a level of detail that
attempts to be complete and definitive. (02)
I just wanted to generalize the following statement: (03)
DF
> For events which involve human actions, it often is
> not possible to ensure that all true propositions
> about them are in the knowledge base. (04)
The main point is to replace "it often is not possible"
with the more general phrase "it is never possible". (05)
In fact, there is no part or aspect of the physical world
for which the CWA (Closed World Assumption) could be true
-- i.e., the claim that all possible true statements about
that part could be derived from a finite set of axioms. (06)
That is even true of some region of intergalactic space that
might happen to be a perfect vacuum. According to current
physical theories, even a vacuum could have random quantum
fluctuations. (07)
The CWA could only be true about something that is defined by
an arbitrary convention -- for example, a mathematical theory
defined as the deductive closure of a finite set of axioms. (08)
A game of chess is an example of a situation that is reduced
to a closed mathematical system when all the physical details
of the board, pieces, and players are, by convention, ignored. (09)
Another example would be an airline reservation that is declared
to exist if and only if it can be found in a particular database. (010)
Finally, three umpires in a bar were discussing their methods
for calling balls and strikes: (011)
First umpire: I call 'em as I see 'em. (012)
Second umpire: I call 'em as they are. (013)
Third umpire: They ain't nothin' til I call 'em. (014)
The third umpire is right. The CWA holds, by convention,
for baseball statistics. (015)
John (016)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/
To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx (017)
|