On 11 June 2015 at 12:20, Bruce Kellett <bhkell...@optusnet.com.au> wrote:
> LizR wrote: > >> meekerdb wrote: >> On 6/10/2015 1:34 AM, Bruno Marchal wrote: >> >> Can you explain why such interaction is not computable? >> >> No, I was relying on your assertion that physics is not >> computable - which would entail that brain processes are not >> computable, which would imply that comp1 is false. Except >> there's a loophole: if comp1 means replacement by a physical >> object then the physics of that object is not computable either >> and so it might work. >> >> Yes, that does seem to follow. And the brain replacement might happen to >> work, but we'd have no idea how (magic? supernatural?) >> > > Why is it that when ever someone doesn't understand something they jump to > the conclusion that it must involve magic or the supernatural. It is not > possible that we might simply not yet know everything? > Just illustrative. The other available alternatives to reality being computable are oracles, hypercomputers, the physical existence of a continuum, and maybe a few other things this margin is too small to contain. > > I suspect that "physics is not computable" is the /end/ result of Brnuo's >> argument (comp2) - which is supposed to be a /reductio/ on the notion of >> comp1. So comp1 assumes that physics is computable, and that assumption >> leads to the result that it isn't. Which is taken as an argument against >> physical supervenience of consciousness on brains, although it could >> equally be an argument against brains performing computations. >> > > If that is the line of reasoning, then it would help if it were made more > explicit. I expect that the reason that it is not more explicit is that it > is actually incoherent. If comp1 leads to the conclusion that comp1 is > false, then comp1 is inconsistent. Not just false, *inconsistent*. And as > Brent is fond of saying, /ex falso quodlibet/. Or better, /ex > contradictione sequitur quodlibet/. > I think it is made explicit. Bruno has often claimed that his argument is a *reductio* on the physical supervenience thesis, assuming I've got that right. He is trying to show that the assumptions of comp1 lead to a contradiction (and one of the assumptions of comp1 is that consciousness supervenes on brains). I think that's correct. I'm sure Bruno will correct me if I've misunderstood. -- 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.
