Re: Summary

From: Christopher Maloney <>
Date: Wed, 06 Oct 1999 23:01:31 -0400 wrote:
> 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

I'm tending toward the opinion that the above are all word-games. It seems
that it just depends on your definition of "reality". As Hans Moravec liked
to say, each reality, or physical structure, or mathematical structure, or
what have you, is completely "real" to the observer embedded within it.

Chris Maloney
"Donuts are so sweet and tasty."
-- Homer Simpson
Received on Wed Oct 06 1999 - 20:36:45 PDT

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