On Thu, Oct 15, 2015 at 12:34 AM, Bruce Kellett <bhkell...@optusnet.com.au> wrote:
> On 15/10/2015 12:07 pm, Jason Resch wrote: > > On Wed, Oct 14, 2015 at 1:17 AM, Bruce Kellett <bhkell...@optusnet.com.au> > wrote: > >> On 14/10/2015 4:45 pm, Jason Resch wrote: >> >> Cochlear implants and artificial retinas give evidence toward multiple >> realizability, and therefore, against mind-brain identity theory. They show >> that it is functional equivalence, rather than material/compositional >> equivalence that matters. Since computers can realize any finite function, >> then assuming there are no necessary infinities within the brain, computers >> can realize any functional state the brain is able to realize. For >> physicalism to be correct, you have to believe either that functional >> states are irrelevant to consciousness, or that physics can instantiate >> functional states which Turing machines cannot. >> >> >> That is simply false. >> > > Well that explains it. > > >> Again it's not clear what you mean by computationalism. Bruce can speak >>> for himself, but I think he agrees that strong AI is possible. >>> >>> >> Strong AI implies consciousness is substrate independent. But I thought >> Bruce argued against consciousness being derivable from mathematical >> computations, which would mean consciousness is substrate dependent: that >> it depends on physically implemented Turing machines. >> >> >> I certainly argued that consciousness could not be sustained on platonic >> computations in arithmetic. But that was because I do not accept that such >> things exist. >> > > What evidence have you seen that led you to this conclusion? > > > What evidence do you need to say that something does not exist? Absence of > evidence is, in this case, evidence of absence. > Why is that so in this case, when the standard form of that phrase is "Absence of evidence is not evidence of absence"? Also, despite your claims to there being no evidence, there is in fact evidence of platonic computations. They exist independently of you, mean, and this physical universe, as surely as "7 is prime" is true independently of you, me and the physical universe. > > > > In mathematics you have descriptions of Turing machines and descriptions >> of computations, but no live machines or computations. >> > > There are both. > > > What evidence do you have for this assertion? > The existence of a UD implies a quantum reality, and we observe a quantum reality. Accepting the truth of arithmetical systems like the axioms of Peano/Robinson arithmetic, implies their existence. > > > > Substrate independence simply means that you can replace all or part of >> the human brain with computer-based equivalents. In other words, strong AI. >> No need for platonia in order to say that consciousness is independent of >> the substrate. >> > > But if it is independent of substrate, and if computations exist > platonically, then those platonic computations are equally capable of > instantiating consciousness. > > > You are confusing the meaning of 'substrate'. In the context, I meant an > explicitly physical substrate. Platonia is an idea, > If Platonia is an idea, then so is "The primary physical reality". It is up to science now, to determine which of these two ideas is more likely to be true. > it is no more 'physically real' than is the idea of a unicorn, or of > Hogwarts School. > Of course it isn't physically real. But why assume physical existence is the only kind of existence? That seems to be an idea based purely faith. > Neither unicorns nor Hogwarts can instantiate consciousness. No more can > the idea of platonia. > The idea of platonia doesn't instantiate consciousness, but objects within platonia do. > > If you want to demonstrate that the idea of platonia can sustain > consciousness of itself, then all you have to do is produce a conscious > being that does not have an accompanying physical substrate. Until you do > that, I think you should shut up about platonia. > Would you demand of Everett to produce a conscious being from another branch of the wave function, or else shut up about the other branches of the wave function? If not, then why demand that I shut up about the consequences of well-accepted theories? > > Why? Arithmetic is system of propositions. Whether it is real or not has >> no effect on Church-Turing. >> > > Then you should be equally happy to have your brain implemented by "unreal > computations" as "real computations" :-) > > > Computations in platonia are 'unreal' -- they do not exist, so cannot > implement anything. > > You said earlier that you have no evidence that objects of platonia do not exist. So why insist so adamantly that they do not? > > and it's difficult to make sense of computationalism if you can no longer > define computation or computability. So if you accept computationalism, you > are implicitly accepting infinity and arithmetical realism. Given this, the > rest of Bruno's result is a logical proof, which is either correct or has > an error. > > > No, you missed the point that it is not a logical proof. It's an argument > from incredulity. > > "A Turing Machine either reaches a halting state or runs forever" > "A Turing Machine can emulate any other Turing machine" > "A Turing Machine has an unlimited tape" > > None of the above items are true for physical approximations of Turing > machines. If these basic principals of computer science are not true for > physical Turing machines, then what kind of Turing machines are they true > for? Is Computer Science founded on lies, or does it concern itself with a > recently-discovered mathematical object for which these statements are true? > > > The definition is of an ideal Turing machine. No such ideal machine > exists. Mathematical objects are idealizations: they do not exist. Any > realization of a mathematical objects is necessarily less than ideal. > > > If you born in a universe with slightly different laws, you would say this > universe is only abstract and doesn't exist. I think you are just biased by > what is familiar to you. > > > No, I am talking about physical reality. Other universes with different > physical laws may or may not exist. > So other laws are possible, so long as those other laws do not describe the operation of a Turing machine executing some program? > If they do exist, they are, by hypothesis, physical. > Just so long as those other universes do not consist of a Turing machine executing a program. > So they can sustain Turing machines and computations, maybe even > consciousness if there are beings around capable of building a physical > Turing machine. But this is not so for platonia. It is an idea, it is > abstract, it does not exist in the required physical sense, so it can do > none of these things. > Are you familiar with Max Tegmark's idea that physical existence is mathematical existence? - https://en.wikipedia.org/wiki/Mathematical_universe_hypothesis - http://arxiv.org/pdf/0704.0646.pdf - http://www.amazon.com/Our-Mathematical-Universe-Ultimate-Reality/dp/0307599809 Jason -- 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.
