Thanks Bruno for being so patient with me and taking the time to
carefully answer my queries.


On Oct 28, 3:42 pm, Bruno Marchal <> wrote:
> On 28 Oct 2011, at 01:56, Nick Prince wrote:
> > [BM]
> > The QTI, or the more general comp immortality, or arithmetical
> > immortality is a complex subject, if only because it depends on
> > what
> > you mean by "you".
> > [NP]
> > Can you be more specific on this?
> Well, we have discuss this a lot on this list. Once you accept the  
> hypothesis that we are digitally emulable, it can be shown that we  
> have to distinguish the first person subjective life from the  
> plausible third person description of the body related to that person,  
> and that the problem of relating those first person description and  
> the third person description are not yet solved. But for the  
> immortality question, we are obliged to consider thought experience  
> involving amnesia, and those experiences illustrates that the notion  
> of personal identity is quite relative, and, with mechanism, they  
> makes no absolute sense at all. They might depend on what *you* want  
> to consider as being *you*. You might consider to be immortal just by  
> succeeding to identify you with your core universal identity (the  
> universal machine that you are), and in that case you can consider  
> that you could survive a strong amnesia. Some drug can help some  
> people to "realize" such identification. But we are programmed by  
> nature to resist such identification, and to identify ourselves with  
> our "little ego" which contains our mundane personal histories, and  
> this can make you doubt that you could survive amnesia. Immortality  
> might be a question of personal choice. Assuming mechanism, the  
> question of afterlife can today be shown as being very difficult.  
> Indeed, mechanism breaks the usual mind-brain identity thesis, and  
> consciousness is related to the infinitely many arithmetical relations  
> defining consistent extensions of (relative) computational states. The  
> math leads to a sequence of open problems.
> > [BM]
> > Do you know Kripke semantic? A Kripke frame is just a set (of
> > elements
> > called worlds) with an accessibility relation among the worlds. In
> > modal logic they can be used to characterize modal logical systems.
> > The basic idea is that []p is true in world alpha, if p is true in
> > all
> > the worlds accessible from alpha. Dually, <>p is true in alpha is p
> > is
> > true in at least one world accessible from alpha. For example the
> > law
> > []p -> p will be satisfied in all reflexive frames---independently
> > of
> > the truth value of p. (a frame is reflexive if all the worlds in
> > the
> > frame access to themselves; for all alpha alpha R alpha, with R the
> > accessibility relation).
> > [NP]
> > Sorry but I have no experience in this area but I can see that if yoU
> > adopt non classical logic then it opens up all sorts of
> > possibilities.
> With the mechanist theory/assumption, I find it better to keep  
> classical logic, and to derive the non classical logic from the  
> intensional variants of the logic of self-reference. We have the  
> mathematical tools to study in a clean transparent way all those  
> intensional nuances (which can be proved to exist necessarily as a  
> consequence of the incompleteness phenomena).
> It should be obvious that with the mechanist hypothesis, computer  
> science and mathematical logic can put much light on those questions.  
> But those math are not very well knows (beyond professional logicians).
> > Testing the consequences in reality is the tricky
> > part.   tHE Quantum mechanical formalism has been successful in so
> > many respects so it gives us some  confidence of being on the right
> > track.
> But then you do have the QM interpretation problem. The Everett theory  
> is based on comp (alias mechanism), and I have shown that comp  
> generalizes QM. A priori there are more computations than quantum  
> computations, but a posteriori the quanyum computations can win a  
> "measure battle" in the limit.
> > [BM]
> >  Then, as other have already mentioned, what will remain unclear
> > (and
> > hard to compute) is the probability that you survive through some
> > memory backtracking. The cat might survive in the worlds where he
> > has
> > been lucky enough to not participate to that experience, and, for
> > all
> > we know, such consistent continuation might have bigger weight than
> > surviving through some quantum tunnel effect saving the brain's cat
> > from the poison. The computation here are just not tractable, if we
> > assume quantum mechanics, and still less, assuming only the comp
> > hypothesis. The only certainty, assuming comp or QM, is that "you"
> > cannot die. But obviously you can become amnesic of some part, if
> > not
> > all, your existence, or you existences. Like Otto Rossler summed up
> > well : consciousness is a prison. With comp, and I think with QM,
> > there is no escapes from being conscious, in a way or another. I
> > don't
> > like that, but then it is a consequence of those theories.
> > [NP]
> > Consciousness could be a prison yes.  but MWI may be false of course,
> > in which case maybe not.  If comp says yes it is - as you suggest,
> > then that's another matter.  The question then is: is comp more
> > fundamental than QM and if this be the case,
> Comp is more fundamental that QM. Yes. I argue in that direction since  
> a long time. It is not easy because it literally force us to backtrack  
> toward Plato, and to abandon Aristotle metaphysics (but not  
> necessarily his logic, biology, and even physics up to some obvious  
> correction). But the basic idea is that with comp the physical reality  
> is not the fundamental reality. The physical reality becomes the  
> "border" of the universal mind (of the universal machine(s)). To be  
> short.
> > should there not be some
> > way we can utilise its predictive capabilities to distinguish (prove?)
> > which interpretation of QM is the right one?
> Comp extends the MWI of physics into a MWI of arithmetic.  
> Theoretically you can derive the whole of physics from the numbers'  
> addition and multiplication laws by using the machine self-reference  
> logics. Up to now, we find a quantum logic rather similar to the one  
> by von Neumann and Birkhoff, but it is an open problem if it is  
> (ortho)modular or if we need von Neumann algebra or sub-Hilbert  
> spaces, finitely or infinitely dimensional, etc.
> The practical weakness of such an approach to physics, is that it is  
> very complex mathematics.
> The conceptual advantage is that we can distinguish the logic and math  
> of the quanta and the qualia. The qualia are characterized by  
> accessible but unprovable truth (for the machine) obeying to the  
> probabilistic variant of the provability predicate. The main variant  
> here is the "no-cul-de-sac-definition": that is the substitution of Bp  
> (beweisbar 'p') by Bp & Dt (beweisbar 'p' and consistent 'truth'). The  
> adjunction of Dt (diamond t, consistent 't') makes the machine  
> abstracting from the cul-de-sac worlds.
> Of course, for the ideally correct machine,  Bp implies Bp & Dt, but  
> the machine cannot prove that (it would prove Dt which is impossible  
> by the correct machine incompleteness).
> I am sorry if this looks a bit technical, but in that very complex  
> subject, being technical is the only way to be shown wrong and to  
> progress.
> Bruno
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