On 06 Mar 2011, at 14:16, Andrew Soltau wrote:

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On 07/02/11 15:22, Bruno Marchal wrote:Comp makes precise that saying to be a machine is equivalent withsaying that there is a level of functional substitution where my(first person) consciousness is invariant for a substitution madeat that level. Comp can show that we can never known our level ofsubstitution, and my reasoning works whatever I mean by my brain(it could be the entire galaxy or the entire observable universe ifsomeone asks for it). CTM is vague on the level, and miss the pointthat we cannot know it, if it exists.Comp is also much more general than CTM, which relies usually onsome amount of neurophilosophy, or on representationalist theory ofthe mind, and CTM is often criticized by 'externalist', like brentMeeker for example. But comp is not annoyed by externalism, giventhat it defines the (generalized) brain by the portion of universeyou need, like possibly the matrix above.So comp is a very weak, and thus general, hypothesis. And theresult is easy to describe: physics is not the fundamental branch.You say "And the result is easy to describe: physics is not thefundamental branch.". This is the leap of yours I never understand.Do you posit that a mathematical universe with no physical contentsomehow automatically computes?

`Computations have been discovered by mathematicians, in mathematics.`

`Models of Sigma_1 complete theories automatically computes indeed. It`

`is a theorem, even without Church thesis. In physics people usually`

`bets that some physical devices can approximate such computation. But`

`apart from Landauer and some others, the notion of physical`

`computation is not yet even well defined.`

`My leap is a consequence of step seven already, in case the apparent`

`universe is robust. Then the MGA eliminates the assumption of the`

`existence and of the robustness of a physical universe.`

Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.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.