Re: Summary

From: <GSLevy.domain.name.hidden>
Date: Sun, 3 Oct 1999 01:17:26 EDT

In a message dated 99-10-01 07:28:42 EDT, Bruno Marchal writes:

>>I would like to add something about LIP (Leibnitz Identity Principle) :
>>I accept it in non-modal (extensional) context. For exemple if you tell me
>> that a = 3, I accept that a + 1 = 4.
 
>>But I don't accept it in modal (intensional) context. For exemple if you
>> tell me that a = 3, I will NOT infer that "Jean knows that a + 1 = 4", for
it
>> is possible that although a = 3, Jean doesn't know it.

>>What I have said in my last post follows from the fact that the 1-person
>>and 3-person notion introduces modal contexts.

>>Listen, people, I don't belief you can keep talking about worlds and
>>observers without using a minimal amount of MODAL LOGIC.
>>I told you that before.

I agree Bruno, I don't know much about modal logic and I'll try to brush up
on it. From what you wrote above, you are saying that LIP (Leibniz
Indistinguishability Principle) comes in two flavors.

The first is the non-modal extensional version which says that if two
particular items appear indistiguishable to an observer, then in so far as
this observer is concerned, these two items are one and the same. However, he
cannot conclude that these two items will appear indistinguishable, and hence
be identical to other observers. This conclusion is very much in keeping
with Relativity Theory.

The second version of LIP is the modal intensional version. It says that if
two items appear to be indistinguishable to an observer, then these two
items, not only are identical insofar as the observer is concerned, but are
also indistinguishable and identical to other observers. This version
supports a view of the world which is absolute.

It seems that if we extrapolate the above, we are heading toward having to
decide whether reality is subjective and relative, or objective and
absolute. Extrapolating still further, we are led to having to make a choice
between a Many-Perspectives Interpretation and a Many-Worlds interpretation.
The Many-World Interpretation would support an objective world independent of
the consciousness that inhabits it; and the Many-Perspective Interpretation
would consider each SELF as the center of its own universe (perception) -
kind of like a distributed solipsist point of view. The only absolute entity
in the Many-Perspective Interpretation would be the Plenitude itself.

George Levy
Received on Sat Oct 02 1999 - 22:33:53 PDT