On Mon, Dec 26, 2011 at 3:44 AM, Bruno Marchal <marc...@ulb.ac.be> wrote:
> > On 26 Dec 2011, at 05:47, Joseph Knight wrote: > > > > On Sat, Dec 24, 2011 at 9:05 AM, Bruno Marchal <marc...@ulb.ac.be> wrote: > >> >> On 23 Dec 2011, at 20:16, Joseph Knight wrote: >> >> >>> >>> The same problem arises in *Part 2*. Bruno claims that we are forced to >>> accept that Alice’s consciousness supervenes on the film. >>> >>> No. On the projection of the pellicle on the Boolean graph, and then on >>> the Boolean graph missing part. The idea is that we built again the right >>> physical activity, with the projection of the film playing the role of the >>> cosmic rays. >>> >> >> What is a pellicle? (Sorry) I understand this part, however. My >> objections arise later. >> >> >> A film. (But in french "film" is for cinema (movie?)). >> > > OK, there was no confusion. > > > OK. > > > > >> >> >> >> >> >>> >>> but (film + optical graph) is certainly changed, and Alice’s dream turns >>> out differently (if it occurs at all). >>> >>> With comp + sup-phys, it can't. >>> >> >> Why? If we assume sup+phys, then some changes in the physical system on >> which the dream supervenes certainly will lead to changes in the dream. >> >> >> I don't think so. Remember that we suppose comp (and sup-phys). So we >> already agree that we can change the physical implementation if it runs the >> computation at the correct level. So, we can change the physical >> implementation as we wish, below the substitution level without changing >> the first person private consciousness. >> > > I think I wasn't clear here. I didn't mean changes in the particular > physical system consciousness is supervening on -- of course by comp that > doesn't matter. I meant that, assuming sup-phys on physical system X, there > must exist some changes in X which lead to changes in consciousness. > > > OK. > > > > > > >> >> >> >> >> >>> >>> >>> >>> Bruno isolates the film and thus reaches his apparent contradictions. >>> But this is not a permissible move. >>> >>> I think that the term "film" could have different meaning in french and >>> english. But the film here means the projection of the pellicle on the >>> glass/crystal medium. This one is never broken. It is a process which takes >>> time, and occur in some place. >>> >>> >>> >>> Not only is the definition of supervenience violated, but his principle >>> of irrelevant subparts is violated as well – for the optical graph is * >>> not *irrelevant for the execution of Alice’s consciousness. >>> >>> >>> Of course, but once we put away the nodes, the physical activity >>> corresponding to the computation are not changed. The optical graph becomes >>> irrelevant for the physical activity on which Alice's consciousness is >>> supposed to supervene, by comp+sup-phys. >>> >> >> This is where my problem lies. Of course the physical activity of the >> system is changed when you (invalidly) remove the optical graph from the >> system. It is far from irrelevant. For example, what mechanism causes the >> light to triggers the lasers? There must be some "internal" mechanisms at >> work as well. The nodes aren't "connected" to one another, but it matters >> whether or not the recording is being projected on an optical graph, vs. a >> concrete wall, vs. movie screen.... >> >> >> Why? The relevant physical activity is the same. >> > Obviously I agree with you (the projection of the film does not >> instantiate consciousness). The point is that if comp and sup-phys are >> maintained, and if 323 is correct, then there is nothing different from >> projecting the film on the glass crystal with the boolean laser graph >> removed and a wall. >> > > I have no problem with 323. My argument is that consciousness never > supervenes on the film/movie/recording. > > > I agree with that. If only because there are no more any computation done > "in time and space" (the original abstract computation does not disappear, > of course, so with comp, we will have to attach consciousness to it, and > not to its particular "concrete implementation". > > > > > So there *is *something different between projecting the film on the > glass crystal, and the wall. The relevant physical activity, in the two > cases (glass/crystal vs wall), is not the same. In the first case (and not > the second) the light interacts with the crystal medium and triggers the > lasers. How can you argue that this interaction is irrelevant and can be > removed? > > > Because that special activity has nothing to do with the original > computation. If it were, I could not have said yes to the doctor at the > start. Once the boolean graph is remove, we just get a special weird > screen. And the absurdity is still there: there are no computation done > when we project on that weird sort of screen. > You can still say yes to the doctor. But that activity does have something to do with the computation. Suppose the film were projected upside down, or equivalently that the boolean graph were turned upside down (no change in the physical state of the film). Unless we assume some incredible symmetry in the layout of the graph (contradicting comp), there would most certainly be a change in computation! It *does *matter for the computation what the light lands on. This doesn't violate 323, or comp. It means that the whole system (crystal/glass+film) must be taken into account in your analysis. It is no better than taking half of the brain and ignoring the other half. It isn't a matter of substitution level. > > > > > > >> >> >> >> Let me restate my concern: Consciousness supervenes on the optical >> graph+the recording, *even when the nodes are completely disconnected. *It >> is true that "most of the work" is being done by the recording, but not all >> of the work. The optical graph still matters, and the "physical activity" >> of the system is not solely provided by the recording, as it still depends >> on how the projected light interacts (physically) with the glass/crystal >> surface. >> >> >> But this is no more relevant in term of the computation, which is >> supposed to be a copy of the brain processing at the right level or below. >> >> >> >> There is a point in the argument at which you ignore the glass/crystal >> system and focus solely on the movie/recording, claiming that Alice's >> consciousness supervenes on the movie/recording. But this is false. *At >> no point *does Alice's consciousness supervene on the recording, *not >> even *when the nodes are completely disconnected. >> >> >> Yes. That's why it is a reductio ad absurdum. >> > > Its a reductio ad absurdum only if you artificially ignore the interaction > between the projected light and the crystal medium and lasers. Because > consciousness supervenes on crystal/glass/nodes+film, it is not meaningful > to make this move. Consciousness changes do not imply film changes (even > though the converse may well be true). You have isolated a subsystem from > the machine, mistaken this subsystem for being sufficient for consciousness > to supervene on -- little wonder an absurd conclusion follows! > > > I could because all this is supposed to be done below the substitution > level. > I understand that, but I don't understand how it addresses my point. > > > > > I am trying to think of an analogy to another system which would make my > argument clearer (and in the process learning how tricky the concept of > supervenience can be). > > > > Actually, I do the same. I search a system where I can make it clearer why > the idiosyncrasies of the movie-graph are simpler to evacuate. > But in the present case, it seems rather obvious to me that the absurdity > is already there, before replacing the glass+smoke by a usual screen. There > is already no more computations, we can already use the stroboscopic > argument to make that absurd. > I am not familiar with the stroboscopic argument. > > 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 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. > -- Joseph Knight -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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