On 12 Aug 2009, at 16:38, David Nyman wrote:

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> > 2009/8/12 Bruno Marchal <marc...@ulb.ac.be>: > >>> The solution then seems obviously to be to throw one or other of >>> these >>> supposed causal principles out, i.e.: >>> >>> 1) either it is the case that consciousness simply supervenes on >>> particular physical activities whose computational status is >>> irrelevant; >> >> ... but then comp is false. OK? And thus comp implies "2". > > Yes, absolutely Definitely. No question. > > 1) is what I always believed, for the reasons I've given, but I hadn't > taken 2) to be a serious possibility. Now I'm prepared to entertain > computational supervenience, because I'm intrigued by where it might > lead us. It's genuinely illuminating. I think it is. But, with Church thesis, it is even more so. We get the class of computable functions, which appears to be close for the most transcendental operation in the whole of mathematics, diagonalization. It is a arguably a "bit" more than "causally closed". And enough equivalence theorems makes computational supervenience a precise mathematical phenomenon. The seventh step of UDA, and indeed the Universal dovetailing itself, makes sense only through the assumed existence of universal machines. (Church thesis asserts that Lambda Calculus, Lisp, fortran, c++, game of life, quantum topology, are name of such universal machine/word/ number). > > >>> 2) or it is the case that consciousness supervenes on computation >>> itself independent of physical activity (the conclusion that you in >>> fact draw from the MGA). >>> >>> In the second case - i.e. the reversal of number and matter - I >>> agree >>> that you can save any role for primitive matter only at the cost of >>> rendering it dualistically epiphenomenal in the sense sometimes >>> attributed (IMO incoherently) to consciousness in materialist >>> accounts. >> >> But then by UDA1-7, not only "stuffy matter" would be epiphenomenal, >> but it would have absolutely no relationship with any observation, >> making it entirely spurious. > > Agreed. In any case, for me, epiphenomenal and spurious are hardly > distinguishable. I will not stickle on that point :) Can we say that? > > >> Note that what you describe here as MGA is Maudlin's later and >> different argument. MGA is also immune to an objection made by >> Russell, which is that QM does "realize" the couterfactuals. >> Maudlin's >> argument can be saved from this with a version where Olympia >> simulates >> classicaly the quantum evolution of the brain. So MGA is more simple >> and direct. Anyway, the conclusions are the same, comp forces the >> abandon of the physical supervenience thesis. So comp forces to >> restrict the supervenience thesis on the mathematical computations >> (computationalist supervenience). > > Yes, the argument is an explicit reductio ad absurdum, which is > contained within my own version by default. Intuition is of course > somewhat personal, but the form of the argument against physical > supervenience I presented - which I think first arose from the mix of > fascination and horror produced by reading Hofstadter, Dennett et al - > has always seemed obvious to me, and the defences against it just > wrong-headed. The belief in comp + physical supervenience strikes me > as the most arbitrary and incoherent form of dualism out there, and > why its proponents just don't get this is a complete mystery, as far > as I'm concerned. But then life is full of mystery. Fortunately :-) The problem is that many materialists use "physicalist comp" to hide, somehow, the mind body problem. We would be "mere machine." But if we are "mere digital machine", and if we don't eliminate consciousness and person, we have to justify the apparent computability of the sharable neighborhood from a sum on the whole universal dovetailing, which is a tiny (Sigma_1) part of arithmetic. We live in the "natural" matrix that you get with any universal system, be it the game of life or numbers with succession, addition and multiplication. The matrix is infinite, and, by first person indeterminacy, "we" are dense on its border (like the mandelbrot set). It remains to explain why, from inside, that infinite sum takes the shape of a quantum sum. The quantum sum does eliminate the white rabbits (WR), but with comp we have to show why in appearance the quantum WR-hunters win on all possible comp WR-hunters. The second "crazy", but """"obvious"""", fact: is that we can already have a chat with the universal machine, on that question. AUDA. But alas, this is obvious only through an understanding of some theorems: Gödel, Löb, Solovay and some others, which themselves requires some knowledge in mathematical logic. Comp, as it should be expected, gives a prominent role to computer science, logic and mathematics. And question concerning "I" and selves gives a prominent role to the mathematical theory of self-reference. Now, is the ONE a person? I still don't know if that make sense (in "machine's theology"). Who knows? Bruno http://iridia.ulb.ac.be/~marchal/ --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~----------~----~----~----~------~----~------~--~---