2009/8/19 Flammarion <peterdjo...@yahoo.com>: > > > > On 19 Aug, 13:35, David Nyman <david.ny...@gmail.com> wrote: > >> It doesn't. It just has to be *amenable* of spelling out: i.e. if it >> is a posteriori compressed - for example into 'computational' language >> - then this demands that it be *capable* of prior justification by >> rigorous spelling out in physical terms for every conceptual >> reduction. MGA claims to show that this is impossible for the >> conjunction of CTM and PM. Of course, CTM on the basis of >> arithmetical realism is not spelled out either, but is immunised from >> physical paraphrase by making no appeal to PM for justification. > > Err. yeah. The hard part is reducing mentation to computation. > The physical paraphrase of computation is just engineering, > >> I understand both your discomfort with arithmetical realism and your >> defence of PM, but this discussion hinges on "CTM +PM = true". >> Couldn't we try to focus on the validity or otherwise of this claim? > > OK. It's invalid because you can't have computaiton with zero phyiscal > activity.
But that is **precisely** the conclusion of the reductio that MGA proposes. MGA claims precisely that - as you say - since it is implausible to justify the ascription of computation to zero physical activity, if you still want to claim that there is computation 'going on', then it can't be attached to physical activity. Are you questioning that MGA constitutes a valid instantiation of a physical TM? What about Olympia? David > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to email@example.com To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~----------~----~----~----~------~----~------~--~---