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. 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. 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. 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; 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'. 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. David -- 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.
