> On 28 Oct 2015, at 9:28 AM, Brent Meeker <meeke...@verizon.net> wrote: > > > >> On 10/27/2015 3:04 PM, Stathis Papaioannou wrote: >> >> On 28 Oct 2015, at 1:30 AM, John Clark <johnkcl...@gmail.com> wrote: >> >>> >>> >>> On Mon, Oct 26, 2015 at 5:16 PM, Stathis Papaioannou <stath...@gmail.com> >>> wrote: >>> >>>>> >> From examples in the physical world. You can give as many >>>>> botanical definitions of the word "tree" as you want but it will just be >>>>> a word defined by other words that are themselves defined by yet more >>>>> words that are.... If you tried to dig for meaning all you'd find is a >>>>> endless loop, it would just be a game where words are manipulated >>>>> according to the rules of botany until somebody forgot about definitions >>>>> and pointed to the ASCII string "t-r-e-e" and then pointed to a large >>>>> photosynthesizing organism made largely of cellulose that exists in the >>>>> physical world. Then even a martian would notice a correspondence between >>>>> this game of manipulating symbols called "botany" that humans had >>>>> invented and the way these large photosynthesizing organism made largely >>>>> of cellulose live. >>>> >>>> > What about a virtual world with trees and observers, and no I/O >>>> devices connecting it to outside trees? >>> >>> There would still be I/O devices connected to the virtual trees made by >>> a computer that operated according to the laws of physics, if not the trees >>> wouldn't even be virtual. And the books on both virtual botany and real >>> botany would still be more than a just a symbol manipulation game, they >>> would have semantic content because there would be a >>> correspondence between the way the symbols are manipulated and the way >>> the virtual (or real) large photosynthesizing organism live. Regardless >>> of if they are virtual or real if you want to know how trees live studying >>> those botany symbols in virtual (or real) books will help, so they must >>> have semantic content . >> >> The requirement that a computation be able to interact with the real world >> puts a restriction on what qualifies as a computation. You've challenged >> Bruno many times to perform a difficult computation using his Platonic >> computer. Well, that computation is occurring in front of you now in the >> thermal motion of the atoms in your desk, which under an appropriate >> interpretation are implementing a Turing machine. But you and Bruno don't >> have that appropriate interpretation, and if you did, you would have the >> result of the calculation already. In other words, the thermal >> motion computation is not understandable as such in, and cannot interact >> with, the world at the level of the substrate of its implementation; so it >> would usually be said that either there is no computation being implemented, >> or it is being implemented only in a trivial and useless sense. But remove >> the requirement for interaction in the real world, and this objection falls >> down. The computation is being implemented, your difficult calculation has >> been completed, and it is being appreciated by the virtual observers who are >> clapping and cheering - even though you can't hear them. > > That's essentially Bruno's MGA, except it stops one step short. Bruno takes > the last step and says even if the atoms of your desk were doing absolutely > nothing there is an interpretation in which that is a computation; hence the > atoms are superfluous. But clearly then it is the interpretation which is > providing the computation.
I agree; if anything at all can be seen as a computation, it is not the thing that matters, but the interpretation. There are two ways to avoid this conclusion. One is to say that consciousness is not computable. The other is to say that a computation can only be implemented relative to the real world. -- 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.
