Thank you for reading the paper in its entirety. Pratt's idea is very subtle but the difference between the form of dualism that he is explaining is very different from Descartes'. Pratt is considering "Mind" and "body" as "process", not "substance". It is the difference between a "Being" based paradigm and a "Becoming" based paradigm.
Please continue and take a look at some of the other papers (http://chu.stanford.edu/ ) and notice how Category theory is being used, notice the contravariant morphisms, notice how non-well founded logic is being used. BTW, non-well founded logics handle the circularity that you appear to protest. This circularity is also a key feature that has to been explained in models of consciousness because, at a minimum, we have to explain "self-awareness"!
Pratt doesn't seem to have address the key notion of forgetfulness in the previously referenced paper, which is necessary to deal with irreversibility, but I am sure that that will be dealt with soon enough.
The "interaction" between the "hand" and the "abstraction" in your example [or better the information representing the physical hand] is obvious. It is not an "interaction", it is an identity in the same way that there is an identification beween a physical object and the class of representations that it can have, be they "bitstrings" or whatever! Interactions, as Pratt explains, need to be explained between the "bodies" and between the "minds". How is it that my mind can interact with yours, or to put it into COMP terms, how does one bitstring interact with another without some physical instantiation?
The interaction problem becomes even more pronounced when we start thinking about QM systems! If you look at the formalism carefully, it is obvious that QM systems are separate from each other in such a way that even the notion of "substance exchange" between them will simply not work. QM systems are exactly like Leibniz' monads: "windowless".
Given this fact how do we propose to explain interactions in general and communication between observers in particular? We can not have theories of our universe of experience that only include a single observer! I know well about particle physics theories talking about vector bosons being exchanged but if you look carefully at the QM system involved, the vector bosons are part of the single QM system being considered and not a separate system. There are technical nuances involved here to be sure, but these ideas are not being advanced without careful consideration. I understand all too well the importance of Occam's Razor. ;-)
----- Original Message ----- From: "Stathis Papaioannou" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Monday, May 16, 2005 9:07 PM
Subject: RE: What do you lose if you simply accept...
I have to confess that the mathematical intricacies of Chu spaces are quite beyond me. However, this passage appears at the introduction to the cited article:
"We propose to reduce complex mind-body interaction to the elementary interactions of their constituents.
Events of the body interact with states of the mind. This interaction has two dual forms. A physical event a in the body
A impresses its occurrence on a mental state x of the mind X, written a=|x.
Dually, in state x the mind infers the prior occurrence of event a, written x |= a.
Tell me if I have completely misconstrued it, but it seems that this is still discussing how the two entities (mind and body) are interacting, and differs only in detail from the 17th century solutions. *Why* do you need to "prove the necessity of epiphenomena", and *how* is such a "proof" providing any more information than the simple observation that the epiphenomena exist? You could go mad seeing dualism everywhere. If I wave my hand in a circular pattern, we have (a) the physical action of moving my hand in a circular pattern, and (b) the circular pattern. Arguably, these are two completely different things. One is an event in the physical world, and the other is a theoretical or mathematical abstraction. How is it that these two completely different entities interact? How can you prove that the physical action of moving my hand in a particular way necessitates the epiphenomenon of the circular pattern? And if you manage to explain that one, how can you explain the experience of being-a-circular-pattern from the inside, or, conversely, the non-experience of being-a-circular-pattern from the inside, whichever is the case? There comes a point where theory and explanation makes us more confused and no more informed than we were before.