Re: Roles and dependence

sowa@west.poly.edu (John F. Sowa)
Date: Tue, 19 Sep 1995 18:01:30 +0500
From: sowa@west.poly.edu (John F. Sowa)
Message-id: <9509192201.AA04276@west>
To: cg@cs.umn.edu, srkb@cs.umbc.edu
Subject: Re: Roles and dependence
Cc: p.m.simons@leeds.ac.uk, phayes@cs.uiuc.edu, phismith@ubvms.cc.buffalo.edu
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Nicola wrote

>I must say I admire
>people able to answer so quickly, but I don't know how can they do anything
>ELSE...

I only answer occasional messages quickly.  The czar who rules west.poly.edu
keeps bugging me about reducing my backlog of 2000 unanswered messages.

Pat Hayes:

>Ah, careful. It does, I suggest, imply that some THING must be an instance
>of another prediacte and have a relation to X. For example a Person must
>have their time of birth. Every concept we have gets its meaning from the
>network of relations that bind it to other concepts. There arent any
>'primitive' ones. 

We must, however, draw a distinction between what is physically necessary
and what is logically necessary.  There is no logical reason why a
human being might not be an uncreated immortal living in a vacuum
without any need for sustenance.  That is, in fact, some people's
concept of God or of the blessed who are resurrected at the end of
the world.  That idea might be physically hard to swallow, but it is
not self-contradictory.

Nicola:

>I report here the complete definition of (strong) conceptual dependence
>taken from Simons' book (see DD2 p. 297, DD5 p. 303)

>A predicate A is (strongly) conceptually dependent on B iff:

   necessary ( (A x) implies (exists y) ((B y) and not (y Part-of x)) ) and
   posssible ( (exists x) (A x) ) and not necessary ( (exists x) (B x) )

Note the modal operator "necessary".

Nicola:

>Coming now to the general position hold by Pat, namely that everything is
>intimately connected with everything else, I believe that the notions of
>dependence used above can help to isolate "islands" within this mess: maybe,
>the notion of "clusters" proposed by you, Pat, many years ago, can be
>revisited in order to use some suitable criterion of dependence in order to
>isolate them.

Although everything in the universe may be related to everything else,
there is a big difference between the various kinds of relations.
Let me use the terms intrinsic/extrinsic instead of the terms
dependent/independent.  The gravitational influence of the earth on
my body, for example, is certainly very important for my daily life.
But I'll call it an "extrinsic" relation because I could conceivably
take a ride on a space shuttle (highly unlikely, but indeed possible)
and I would be essentially the same person, even though I wouldn't feel
any effect of the earth's gravity.  Anything that happened in the past,
even including my birth, is an event that is physically important, but
logically unecessary in the sense that an individual identical to me
might have been created out of nothing two seconds ago.  (The creationists,
in fact, do seem to believe something very much like that.  Some of the
more extreme ones believe that the earth was created in 4004 BC,
complete with buried fossils, which give the appearance of antiquity.
That's another unlikely notion, but not a self-contradictory one.)

By extrinsic relation, I would therefore include all influences of
anything outside my own body and any historical event that may have
occurred at any time prior to the present.  The future, it goes without
saying, is definitely extrinsic.  As far as my own body, there may be
gradations of importance:  my heart and liver, for example, are more
significant for my daily life than my left little finger.  But even my
left little finger is more intrinsic to me than any other physical object
in my house and certainly more than anything outside my house.

I won't attempt to give a formal definition of the intrinsic/extrinsic
distinction, but I would want to include both parts and moments under
intrinsic.  To get back to Peirce's triads, I would say that Firstness
would be definable only in terms of intrinsic relations.  Secondness
would depend on some extrinsic relation.  And Thirdness would be some
entity C, which brings two or more other entities A and B into relation,
where C and B are extrinsic to A, C and A are extrinsic to B, but A and
B are intrinsic to C.

John Sowa