On Wed, Oct 14, 2015 at 1:17 AM, Bruce Kellett <[email protected]> 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? > In mathematics you have descriptions of Turing machines and descriptions > of computations, but no live machines or computations. > There are both. > 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. > > > > > >> >> 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. > [image: Inline image 1] > > > 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. 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 [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.
