On 17 Dec 2011, at 05:26, Pierz wrote:
So I’ve read Maudlin’s argument and I’ve decided to trade in my PC for a brand new Olympia.
Or maybe not – I heard the water bills are a killer. Actually I’m not so impressed, and here’s why. Maudlin attempts to show that consciousness cannot supervene on the physical activity of a computing device by hypothesizing a mechanism which, instead of responding to counterfactual input states in order to accomplish a certain computation, is composed of numerous interlocking mechanisms, each of which is ‘mindless’
This is not relevant. Comp assumes at the start that the part of a computing machinery is mindless (contra Craig).
in the sense of producing the same output regardless of what is input (the state of the ‘tape’ of water troughs), and each of which operates independently of all others. In order for this process to work out, Maudlin must ensure that the trough containing the next bit of information being processed by the armature is always the next trough being read, i.e., the spatial sequence of troughs is the same as the computational sequence of program pi. What then if the armature needs to read an earlier state of the tape? Rather than allowing the armature to backtrack, Maudlin invokes the notion of the ‘bilocation’ of certain addresses. By connecting pipes to earlier troughs, the armature can read an earlier address in the sequence. This is important because as the machine progresses through its sequence of operations, it may fill or drain the troughs it passes over, and these alterations to the tape may be significant for its subsequent processing. Now Maudlin claims that each copy of Klara cannot be conscious, because a machine that produces the same outputs regardless of inputs can never, by the computationalist’s own standards, be regarded as conscious. It is only the conjunction of all the various Klaras in Olympia that achieves a real computation, and yet, because only one copy of Klara is running at any time, the other copies remaining completely inert and separate, the computationalist has a problem. Either he must give up the idea that consciousness depends on a ‘non- trivial’ computation, or he must give up supervenience on the physical.
All Klaras are inert, for the specific conscious computation under consideration. Only the pre-Olympia part is active, but with its physical activity already made arbitrary if not inexistant.
(pre-Olympia = Olympia without the Klaras).
Let us note that in order for Olympia to run a particular computation on a particular input state, she must first be pre-programmed to that input through the configuration of the float devices at each trough, which ensure that a new Klara can be activated at each potential counterfactual branch. This is fine so far as it goes, in that this can be done in advance and amounts to the programming of any computer before it is run. But note that at this programming stage, the results of Olympia’s processing cannot be known, otherwise the program would have to be run first, and that would lead to an infinite regress. That is to say, when I program the float positions, I can’t know how Olympia will fill or empty any particular trough in advance.
So here’s the rub. Let us imagine that Klara instance 1 (we’ll just call her K1) is running and hits her first counterfactual at T4 (trough 4). K2 is now activated at T4 and K1 is shut down. Now let’s say two troughs down at T6, program pi calls for the retrieval of the contents of T1. By bilocation, we know she can do this. But now the armature has a problem. Should it get the contents of T1 in K1 or in K2? Clearly the answer is K1, because the armature has passed over K1- T1 and therefore possibly altered its contents, but K2-T1 has never been processed and contains ‘noise’ as far as the calculation is concerned. As noted earlier, we cannot so arrange K2 that it contains the same contents as K1 after processing, because that would entail running the program in advance. So K2 must pipe the contents from trough K1-T1, thereby activating a supposedly inactive copy of Klara. This itself seems to shoot down Maudlin’s argument, since the transferring of information (water, charge, whatever) from K1-T1 must be accomplished physically, and involves the physical, causal interaction of two different copies of Klara.
Maudlin runs the initial computations. All Klara are and remains inactive during the whole computation.
The problem is even deeper than this, however. How does the system ‘know’ when two locations should be bilocated?
We have run the computation in advance, completely.
This works OK for a single copy of Klara, since she is a static system. But if she must physically interact with all the previous editions of herself further back in the calculation chain, then she will be forced to ‘build’ pipes on the go, a ridiculously contrived procedure that totally vitiates the idea of a mindlessly proceeding, inert system.
I think you miss the point. We consider only the particular computation for which we know in advance that the Klara will not be used. the role of the Klaras is only to reinstore counterfactual correctness, but the physical supervenience is jeopardized by that computation with the Klaras being inert.
And how does Klara (or rather, Olympia) remember which path she has followed in order to know which trough to drain? New mechanisms must be devised which effectively mean retaining the activity of previous Klaras in the chain and are no different from a form of backtracking. If Maudlin’s argument is a foundation of the UDA, then it seems to me the UDA is on shaky ground, though I have yet to investigate the MGA in depth.
MGA is the last step, and is used only for immateriality. UDA has already shown indeterminacy, non locality, etc. MGA is only a remind that the mind body problem is not solved, and that we have no idea of what "matter" can be.
People talk about the Movie Graph Argument, but the links provided refer to Alice and a distant supernova with lucky rays that substitute for functional neurons. I don’t see a connection to the idea of a recording or a filmed graph. Can someone enlighten me?
See "Le paradoxe du graphe filmé" here, in the voume 3: http://iridia.ulb.ac.be/~marchal/bxlthesis/consciencemecanisme.htmlYou will find drawings showing how to translate Olympia in term of filmed graph. Or, if you want, we can come back on this. I have just not so much time right now. You can see that Maudlin got the movie idea also, at the end of the paper.
Bruno, I'm aware I've left a prior discussion hanging regarding measures of infinite sets. I read up on the material you linked to and it seemed to me that amenability of integers depends on them being taken as a sequence, not a mere set. But I don't really (at all) understand the difference between sigma and simple additivity. Perhaps you can explain? And is this discussion related to the 'credibility measure' you mention elsewhere?
I was just pointing on the fact that it is false that there is no measure on infinite discrete sets. But UDA does not suggest we need that. So the sigma-additivity notion would distract us from the topics. Eventually I can explain the difference in some other post, but it is not related to the topics. I have begun the extraction of the measure by the use of the self-referential logics, in AUDA. That comes after the UDA.
On Dec 17, 3:06 pm, Russell Standish <li...@hpcoders.com.au> wrote:On Fri, Dec 16, 2011 at 05:42:19PM +0100, Bruno Marchal wrote:On 16 Dec 2011, at 10:39, Russell Standish wrote:On Mon, Dec 12, 2011 at 04:11:54PM +0100, Bruno Marchal wrote:Maudlin's argument relies on the absurdity the the presence or absence of inert parts bears on whether something is consious. This absurdity only works in a single universe setting, however. If your computer is embedded in a Multiverse, the absurdity vanishes, because thiose inert parts are no longer inert.But they do not play a part in the computation, at the correct substitution level.They certainly look like they are. If these parts weren't present, thecalculation proceeds differently in the other branches of theMultiverse. In other words, counterfactuals are not handled correctly.If you think of a quantum multiverse, then that argument would work if the brain is a quantum computer. If it is classical, its statesNobody here is proposing that the brain is a quantum computer. Penroseand Lockwood do, but that's an entirely different hypothesis.can be considered as having been prepared in the classical base, and the computation (or non computation) will be handled correctly in each branch of the quantum multiverse, in which the same MGA reasoning will apply.In Maudlin's argument, the inert parts are only inert by virtue of thecounterfactuals not having been realised. In a multiverse, the counterfactuals are realised, but in different branches. Hence those "inert" parts are no longer inert in all branches. If they were, they could be removed from the computer altogether, without affecting the computation.So you are introducing a different kind of physical multiverse, which would handle the counterfactuals. But this will not work. Either this physical multiverse, which plays the role of the generalized brain, is Turing emulable, in which case I can emulate it in a single Turing machine, for which the MGA will apply again. Or it is not Turing emulable, but then the need of it will contradict the comp assumption.This step, as I understand it, is a form of dovetailing. Nobody reallythinks of the dovetailer algorithm as instantiating consciousness, so the move is ultimately invalid, I would think.They are playing a part concerning the first person indeterminacy, like in the UD*, or in QM physics. But that is derived (and has to be) from the indeterminacy.They do that as well, but this is not relevant to Maudlins argument...The parallel realities does not play any role for a classical computation, except for statistical interference (in case of a quantum computer).It is not a question of the parallel realities playing a role in the computation, but in the supervenience. Maudlin's argument says If COMP, then supervenience on single universe is contradictory. But itdoesn't say anything about supervenience on multiple parallel realities.But if this play a role, it means that we have not chosen the right level of substitution. Once it has be chosen correctly (or below), what happens in some other branch cannot interfere or play any role in the computation.I don't follow...If you then fold the multiverse back into a single universe by dovetailing, one can then reapply the Maudlin move.Indeed. That is the key point.But then, in that case, one can embed that result into a Multiverse, and the cycle repeats.I think I'm coming around to the view that neither of the above stepsare valid - but one could equally say they are as valid as each other.... snip ...If the register "323" is missing in one branch of a quantum multiverse, it is missing in all normal extension of the computational state of the machine.Yes...Some rare branch will have the pieces, and from there (and thus from the first person point of view of the subject) everything will go well, by comp.This is a bit confused. Surely the register is missing in all future branches,But only because we fall back in a branch where the piece is not missing.Why? Are you saying that if consciousness requires the presence of register 323 at some particular point, then we find ourselves instantiated by a computer with such a register? But then surely, never at any point would we find ourselves instantiated by a machine without register 323 - presumably for most of our history we would be unaware of whether the register existed or not.This is not different than the comp or quantum immortality argument. The fact remains: the physical activity in one normal branch missing the register is the same as the physical activity in some branch not missing it, for the same particular computation.In all branches, or just special ones? If all branches, then the register is totally unnecessary. If just a special pair of branches, then Maudlin's argument shows that supervenience must occur across more branches than those two.Then Maudlins argument shows correctly that the physical activity can be made arbitrary (and even non existing), showing that comp links consciousness not on the physical activity of the program, but on the computational (in the sense of computer science) structure only, making matter and physics an epistemological indexical for the conscious entity involved.The question is - where is the consciousness in all this? I think it must move with the levels - and given the UDA and COMP, I would say that consciousness appears at the Multiverse level, not the singleuniverse level.That is right, but with comp that "multiverse" is the mathematical structure which needs to be entirely derived from the theory of consciousness or from the self-reference logics.Why? I can see how, but why?Keeping comp, we might say "only by Occam", but that would be weak, given the fact that not much of known physics is handled by comp currently. But then the reason why we have to do that, even without Occam, is the MGA argument. If some physical reality is at play in the brain for it having a role in the making of consciousness, comp makes it Turing emulable in a single reality, and it that single reality we can change the computer structure so that his physical activity is arbitrary, by adding, like Maudlin some physically inactive piece of matter, for handling the counterfactuals. And what I say above will apply.Yes - it shows that physical supervenience is impossible in that single reality. But this doesn't answer the why question. I could imagine that you might feel that Multiverses are otiose, so would prefer a derivation of their existence from something "simpler" - eg arithmetic of the whole numbers. That's fine and dandy - but the Multiverse is not otiose - it is far less of an impost than a single reality. I know you're keen to attack the Aristotelian primary matterposition. To be quite honest, its not a question I care too much about- I'm happy for my matter to be phenomenal, not primary. But I do think we need to be careful about throwing out supervenience of mind on matter (of whatever stripe), otherwise the Anthropic principle becomes mysterious, and we're faced with what to do about the Occam catastrophe. I'm snipping the following text because it moves away from Maudlin'sargument in particular, and also there's some juicy stuff in it I needto absorb before responding (if indeed I do :). ...snip... -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au ------------------------------------------------------------------------------You received this message because you are subscribed to the Google Groups "Everything List" group.To post to this group, send email to email@example.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 .
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