On 10 July 2014 21:21, meekerdb <meeke...@verizon.net> wrote: > But I think it becomes absurd only because the scenario ignores the fact > that it is the physical instantiation that provides a reference to the world > which then gives the computation meaning. It is the implicit isolation into > "physical system which is going through a computation" that gives the > impression that it is just the sequence of states that instantiates the > computation.
It might save you some typing if you read the whole post before you comment on a part of it. I dealt with this point a couple of sentences later. > Under physicalism, if it goes on walking and quacking like a computation, > then it *continues to be* a computation; the physical states and outcomes > are what *constitute* a computation. > > OK, if by "physicalism" you include that the computation "goes on" in the > physical context of a world. Yes, just so; now read on. > Furthermore, we need not suppose any such system as the one in question to > be isolated from the rest of the world and hence devoid of reference. The > 'relation with the rest of the world', under physicalism, is fully satisfied > by the *physical* relation of the system in question with the rest of the > *physical* world. > > Right. Yeah, right indeed. The system as described continues to relate physically, in the relevant ways, with the rest of the physical world. If I may quote my next sentence "As long as the relevant sequence of physical states is unchanged there can be no reason to complain that this requirement can't be met." So what precisely is your remaining objection? > So after all this we are faced with not one, but two, options. > > 1) CTM is false and physicalism is true but incompatible with > computationalism; > > What do you mean by "computationalism"? Just saying "yes" to the doctor? No, I mean the assumption that a physical system can be conscious simply in virtue of its "implementing" a computation. Since in the gedanken experiment we have succeeded in evacuating any trace of "computation" from the system, whilst preserving its net physical action, if it remains conscious, it can't be in virtue of its ever having implemented a computation. If on the contrary we conclude that it "loses consciousness", we then have the mystery of how this can be the case given that the sequence of physical states remains the same. Either way the conjunction is shown to be incompatible and it would be unsafe on this understanding to say "yes" to the computationalist doctor. > 2) CTM is salvageable but not in the case that physical activity is the true > 'basement level'. > > Why not? Why isn't the option that CTM is true but the "C" must be a > sequence of states instantiated in the context of a physical world - where > the physics need not be fundamental (but could be). ? If you still want to claim this either you haven't yet quite grasped all the implications of the MGA, or the "physical world" to which you now refer can't be the one that has featured in the argument to this point. We've already shown that we can evacuate all traces of computation from *that* world whilst preserving its sequences of physical states complete with all relevant relations to an external physical environment. Hence to hang on to the "C" we must look to computational relations to be primary, rather than secondary, in our explanatory strategy. This in turn implies that any "physical world below computation" would have to be consigned to some explanatory "sub-basement"; IOW a world of "ur-physics" that existed merely in order to "implement" computational relations. It is the latter that must do all the work in our "explanatory basement". Hence, to appropriate an image of Bruno's, the putative ur-physical sub-basement would merely be there to stable a sort of supernumerary "invisible horse" whose sole purpose is to "pull the numbers around". Sure, we could posit its "existence", but it couldn't otherwise feature in our explanations. > This entails what Bruno calls the > reversal of physics and machine psychology. > > That's possible, but I don't see it as the only possibility. Granted, I guess. But would you care to suggest some viable alternatives? David > On 7/10/2014 12:49 PM, David Nyman wrote: > > > On 10 July 2014 19:39, meekerdb <meeke...@verizon.net> wrote: >> >> In short, under physicalism, a 'computation' *just is* a particular >> sequence of physical states. Indeed what else could it be? The states, so to >> speak, come first and hence the notion that those states 'implement a >> computation' is always an a posteriori attribution that neither need, nor >> can, bring anything further to the party. >> >> >> I agree with all you wrote. But as Bruno says it's a reductio. Given >> that it's absurd, the question is what makes it absurd. I think it's the >> assumption that the sequence of physical states constitutes a computation >> *independent* of any reference to a world. When you talk about your PC and >> accidental compensation for a physical fault, the concept of 'compensation' >> already assumes a correct operation - but what makes an operation >> correct?...it's relation to you and the rest of the world. A computation, a >> sequence of states simpliciter, could be a computation of anything or of >> nothing. So the intuition that the computation still exists without the >> physical instantiation is contradicted by the intuition that a computation >> must be about something. With conflicting absurdities I'm left unconvinced. > > > But the MGA has never been claimed to show that computation exists without > physical instantiation. The consequence it presses on us is rather that it > is absurd to accept a series of physical accidents or a recording as > continuing to implement a computation. Yet that would be the conclusion > forced on us by the conjunction of physicalism and computationalism. > > > But I think it becomes absurd only because the scenario ignores the fact > that it is the physical instantiation that provides a reference to the world > which then gives the computation meaning. It is the implicit isolation into > "physical system which is going through a computation" that gives the > impression that it is just the sequence of states that instantiates the > computation. > > I suspect that this is related to Bruno's use of Thaetetus definition of > knowledge which doesn't require any causal relation between belief in a true > proposition and the fact that makes it true. > > > Under physicalism, if it goes on walking and quacking like a computation, > then it *continues to be* a computation; the physical states and outcomes > are what *constitute* a computation. > > > OK, if by "physicalism" you include that the computation "goes on" in the > physical context of a world. > > > Furthermore, we need not suppose any such system as the one in question to > be isolated from the rest of the world and hence devoid of reference. The > 'relation with the rest of the world', under physicalism, is fully satisfied > by the *physical* relation of the system in question with the rest of the > *physical* world. > > > Right. > > > As long as the relevant sequence of physical states is unchanged there can > be no reason to complain that this requirement can't be met. > > So after all this we are faced with not one, but two, options. > > 1) CTM is false and physicalism is true but incompatible with > computationalism; > > > What do you mean by "computationalism"? Just saying "yes" to the doctor? > > > hence, if the system in question continues, after the postulated > disruptions, to support some conscious state it can't be in virtue of its > ever having implemented a computation. This leads to its own nest of > puzzles. > > 2) CTM is salvageable but not in the case that physical activity is the true > 'basement level'. > > > Why not? Why isn't the option that CTM is true but the "C" must be a > sequence of states instantiated in the context of a physical world - where > the physics need not be fundamental (but could be). > > > We must hope to elucidate some more deeply concealed basement where, in some > formalisable sense, number relations are sufficient and computation itself > is the key organisational principle. This entails what Bruno calls the > reversal of physics and machine psychology. > > > That's possible, but I don't see it as the only possibility. > > Brent > > -- > 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 everything-list+unsubscr...@googlegroups.com. > To post to this group, send email to everything-list@googlegroups.com. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. -- 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
