Re: [ontolog-forum] Fwd: Ontologies and individuals

[William Frank <williamf.frank@xxxxxxxxx>]

I agree that the distinction between individuals and kinds is a convention.  But  it seems as troublesome as it is necessary. 

There is another aspect, neither trivial nor profound, but practical, though it has profoundly bothered many. 

How do you know whether the class only has one member?  Moslty, you only know of one **so far**.  How do you decide whether two separate observations are observations of the same thing or of different things?   If you use a set of attributes to define a class, if there just **happens** to be only one member, there might be instead zero or more, at some other time.   Individual appear to be things such that every one is different from every other one, by definition. 

I thought these days most people in the business of trying to understanding what it is to be an individual believe that it is *history* that differentiates otherwise identical things.  This history, in the easiest instance, for physical things, usually involves contiguous locations in space through contiguous moments in time.

On Thu, Dec 13, 2012 at 9:14 AM, John F Sowa <sowa@xxxxxxxxxxx> wrote:

Dear Alex,

That question is either trivial or profound.

AT
> I am not sure I understand why an 'identification' of an individual
> thing is considered separately from a 'classification' of an individual
> thing. Personally I see the 'identification' requirement as a necessity
> to find out (define) a class of individual things which has only one
> member - that particular individual thing.

The trivial answer is that many logics make a sharp distinction between
individuals and types (or the classes or predicates associated with the
types).

If you have a logic that makes that distinction, then you identify an
individual by finding some symbol (such as a character string) that was
assigned as the name of that individual. But you classify an individual
by determining the names of types or classes of which it is a member.

But if you analyze the psychological, linguistic, and philosophical
issues, you'll find that there is no sharp distinction.  What people
and other animals usually perceive are images of the types, and the
particular individual is inferred from the patterns of types and
the context (more patterns).

There are no sharp boundaries between images of distinct individuals,
images of the "same" individual at different occurrences, and images
of distinct, but similar individuals.  All those distinctions must be
learned, and mistakes are common.

In short, the distinction between identification and classification
is a useful convention.  Natural languages distinguish them, but NLs
are very flexible.  They allow common nouns to be used as names
(Baker, Butler, Cook, Smith), and they allow proper names to be used
as common nouns (Xerox), verbs (Xerox), or adjectives (Xerox copy).

John

_________________________________________________________________
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

_________________________________________________________________
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    (01)