On Fri, May 08, 2015 at 07:47:42AM +0200, Bruno Marchal wrote: > > > It is because it does not, indeed, and because of the insanity you > need to believe that a movie of a computation is a computation, that
Replaying the movie is a computation, so saying this idea is insane doesn't help. The question at hand is whether replaying the movie is sufficient to instantiate the consciousness moment. Given that the conscious moment already existed at some time in the past, we have to define the physicalist supervenience thesis as supervenience on the here and now, as opposed to the original then and there, in order to drive a possible difference between the computational supervenience thesis (which doesn't say whether the recording is conscious or not) and the phsyicalist one which says it is. I'm not convinced that this version of the physicalist supervenience thesis makes a lot of sense, and I would say that neither Bruce nor John Clark promote this when they say that replaying the recording make not one iota of difference to the actual experience. Perhaps there is another way of skinning the cat. Suppose we have our original computed experience, and the recording made of it. Now let us prepare an ensemble of recordings that vary a little bit from the original. Presumably, if we can arrange the encoding of the recording in a non-fragile manner (fragility of an instruction set refers to how often random mutations of a program lead to non-valid programs - a non-fragile instruction is one where random mutations usually lead to working programs. The genetic code is not very fragile, due to vast amounts of redundancy, but artificial computers are typically very fragile). The point here being that it might well be possible to create a recording of a new conscious experience (albeit very similar to the previously recorded experience), without needing an astronomical amount of monkeys clicking away on keyboards. If this is at all plausible, then we can do away with the troublesome "here and now" aspect of the physicalist supervenience thesis. This still leaves us with whether this new "recording" actually instantiates the new conscious experience in our non-robust universe. The Physicalist supervenience thesis quite unambiguously says yes. Computationalism is simply mute on the affair, as the new "recording" is definitely not the same program as the one that instantiate the consciousness. If we are to accept that instantiating the conscious experience by replaying the "recording" is an absurd notion, then it is clear there is a difference between this PPST and Comp. But I raise the question of whether it really is absurd? The difference between the playback of the "recording" and the actual computation is one of counterfactual correctness. If it is absurd, it can only be absurd because counterfactual correctness is an important feature. But too many people have stated that it is irrelevant... If this counterfactual aspect is important, then the only way to rescue physical supervenience (as opposed to physicalist supervenience aka primitive physical supervenience) and comp is to require that the counterfactuals must physically real as well. This in turn entails some sort of many worlds must be true, and this is back in the robust ontology territory. But to really draw that conclusion requires accepting the absurdity of noncounterfactual program instantiating consciousness. I think more work is actually needed here, as we're talking about very large recordings, something like 1e14 bits per second of consciousness (about 100 Terabytes per second). Replaying this movie in real time is still many orders of magnitude out from current capability. Normal HD movies is only about 500KB per second. I don't have a stake in the outcome either way - I accept the MWI as the preferred interpretation of QM, where the MGA neither works, nor is needed, as ontology is robust. I'm just trying the critique the argument on its own terms. Cheers -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics [email protected] 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 unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
