Roles and dependence

"Nicola Guarino" <guarino@ladseb.pd.cnr.it>
Message-id: <guarino.1161926647F@150.178.2.3>
Date: Tue, 19 Sep 95 20:30:07 +0100
From: "Nicola Guarino" <guarino@ladseb.pd.cnr.it>
Subject: Roles and dependence
To: srkb@cs.umbc.edu, cg@cs.umn.edu
Cc: "Pat Hayes" <phayes@cs.uiuc.edu>, "Peter Simons" <p.m.simons@leeds.ac.uk>,
        "Barry Smith" <phismith@ubvms.cc.buffalo.edu>
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Foreword:

My reaction times to the interesting messages coming from these (two?!)
lists are very slow, due to the fact that I force myself to push them in
background, hoping to be able to do my ordinary work... I must say I admire
people able to answer so quickly, but I don't know how can they do anything
ELSE...

However, I will try to isolate some points in the recent debate about roles
which still require discussion. Let's start with the notion of conceptual
dependence.

Pat Hayes:

>> A predicate like Person, on the
>>other hand, can be conceived as indepedent if the fact that X is a Person
>>does not necessarily imply that somebody else is an instance of another
>>predicate ("Firstness").
>
>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. 

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) )

(the second line of the formula avoids trivial cases).

Now supposing that A is "Person" and B is "TimeOfBirth", then it would seem,
at a first sight, that Person is dependent. The crucial points here are the
meaning of "TimeOfBirth" and the notion of Part-of we use. Suppose that the
extension of "TimeOfBirth" is just a set of numbers (time stamps). As such,
these numbers are not parts of persons, and so we conclude that Person is
dependent.

The notion of Part-of assumed by Husserl, however, was much more general
than the one commonly used, in the sense that he considered the properties
of a thing (like the color of a particular rose, for instance) as parts of
such thing (he called such parts "moments"). In this sense, if we consider a
TimeOfBirth as a particular event and not as an abstract number, we may see
such event as a "part" of a person and conclude that Person is independent.
However, I must say that I don't like such a generalization of Part-of, and
I would better introduce a separate relation like "Belongs-to". The formal
characterization of such relation of such a relation is - I believe - an
open (and important) research issue.

Peculiar aspects of such a relation seem to be the following ones:

- It satisfies most (all?) properties of classical mereology

- If x belongs to y, then x is existentally dependent on y (another form of
dependence, among individuals this time!)

- If x belongs to y, then x and y are of a different "kind" (e.g., x is an
event and y is a physical object)

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.





 


                         ---------------------

Nicola Guarino
National Research Council     phone: +39 49 8295751
LADSEB-CNR                    fax:   +39 49 8295778
Corso Stati Uniti, 4          email: guarino@ladseb.pd.cnr.it
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Italy