re: counterparts

[Andrew Bacon <andrew.bacon@lmh.ox.ac.uk>]

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Hi there,
I'm new to this mailing list, so I've been trying to catch up by going through
the backlogs and I came across the discussion on counterparts. Some interesting
points where raised, but I felt Kripke afforded a rather unfair treatment.
Although I also am probably one of the few that disagree with much of what
Kripke said about proper names, natural kinds, the contingent a priori and
necessary a posteriori and so on, I felt he hit the nail on the head when it
came to transworld identity.

As I read Kripke - when he says transworld identity is 'stipulated in advance'
the kind of stipulation in question is very closely related to the way in which
he constructs his semantics for modal logic. (That is, using model theory in the
Tarskian tradition - in this framework there is nothing problematic about having
the same individual in different models). Identity means literal identity - it
is taken as primitive, not to be explained in terms of something else (i.e. no
need for the 'necessary and sufficient conditions for transworld identity'
nonsense)**. Instead of looking at a world in which Hector is a pirate and
trying to work out who the hell the-Hector-you-know is in this world, you *take*
Hector and place him in the possible situation in which he a pirate. Essentially
its an epistemological problem, not a metaphysical problem - (only in the case
of David Lewis does it also become a metaphysical problem... but we're not modal
realists are we?).

So far so good. So what's all this 'I stipulate that I could have been a frog'
malarkey? Even worse, can I not just stipulate that there is a world in which I
am human and not human? In my reading of Kripke, stipulation goes as far as
constructing possible worlds (according to the kind of models he outlines). This
rules out the second contradictory proposition. So what about the frog
proposition - this is apparently left alone according to Kripke? 

Well it is and it isn't. As far as his modal semantics is concerned the frog
proposition is fine. However Kripke does not believe that modal logic determines
all the modal truths. In fact there are some false propositions which are
actually true according to modal logic (e.g. the frog proposition). This is
included in but does not exhaust the famous distinction between logical and
metaphysical necessity.

The debate between transworld identity and counterparts is a big one, but the
main defendants of each view are Plantinga and Lewis respectively. There are
many arguments for and against each view - but here are the two arguments I find
most convincing. (By convincing I mean they show the opposing view to have
counter intuitive consequences - hence I've omitted Lewis's argument from
intrinsic properties which is undoubtedly important, but I do not think common
sense has much to say about it)

Plantinga - We would normally accept the proposition that it is possible for
Socrates to be more similar to how Xenaphon actually is than to how Socrates
actually is, and for Xenaphon to be more similar to how Socrates actually is
than to how he actually is. However according to Lewis's theory this turns out
false, Xenaphon's counterpart is not Xenaphon (in w) since there is a more
appropriate candidate - namely Socrates. (And similarly for Socrates). I think I
saw this argument being bandied about with out mention of Plantinga, so that's
where it came from if your interested.

Lewis - The transworld identity relation is, and the counterpart relation is
not, transitive. It is surely possible that my bicycle should have had different
tyres, equally it is possible that *this* bicycle should have had a different
bicycle chain while remaining the same... (and so on until the bicycle has
completely different parts). By transitivity of transworld identity it is
possible that a particular bicycle should have been constructed from completely
different parts - something we would be hard pressed to accept. If this example
isn't convincing enough you can run it through by gradually changing me from a
human to a frog.

Anyway, in terms of books Naming and Necessity is very important but equally
important I think are: 
David Lewis - The Plurality of Worlds, 
Plantinga - The Nature of Necessity.

And another good read is (I haven't read it all yet):

Graeme Forbes - The Metaphysics of Modality, 


Also, a side note about Kripke's claim that you necessarily have your parents.
Kripke's view seems entail that the *numerical identity* of objects is a matter
of empirical investigation (That I have the parents I have is according to
Kripke necessary a posteriori). So you cannot know which particular person
someone *is* with out knowing their parents. An example due to Tichy "If it is
true that an object cannot possibly by Elizabeth II unless it has been born of
George and Elizabeth Windsor, then, when examining a woman, one cannot be sure
that it *is* Elizabeth II unless one knows that she was born of those parents
[...] When we say that she might turn out to have been born of the Trumans we
mean that *some other woman*, looking and behaving like Elizabeth II looks and
behaves, in fact, might have been the one under inspection." But then of course,
given we cannot be sure we have Elizabeth II unless we know who her parents are,
we must further determine the identity of her parents by discovering *their*
parents, (and so on throughout the course of history).


Regards,

Andrew

** Note that Kripke appears to be committed to essentialism whether or not he
has the identity relation in his language, quantifying through scopes appears to
commit him already. E.g. Ax[Hx -> Nec Bx] - here I am saying all (actual) humans
are essentially bipedal.

-- 
Andrew Bacon
Lady Margaret Hall
07830048336
http://users.ox.ac.uk/~lady1900



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