Bruno, I agree with Gunther about the two types of machine. The broader machine is any system that can be logically described-- a system that is governed by rules and has a definite description. Such machines are of course not necessarily computable; oracle machines and so on can be logically described (depending of course on the definition of the word "logical", since they cannot be described using 1st-order logic with its standard semantics).
The narrower type of machine is restricted to be computable. > > All known physical causal system are Turing emulable. > I am no physicist, but I've been trying to look up stuff on that issue... Schmidhuber asserts in multiple places that the fact that differential equations are used to describe physics does not contradict its computability, but he does not explain. I know that, for example, Wolfram is attempting a computable foundation for physics, but I don't know about any real progress... so any info would be appreciated. --Abram On Wed, Dec 24, 2008 at 11:58 PM, Bruno Marchal <marc...@ulb.ac.be> wrote: > > > On 24 Dec 2008, at 16:41, Günther Greindl wrote: > >> >> Kim, Bruno, >> >> >>> Not at all. You have already done the first and last leap of faith of >>> the reasoning when accepting the digital brain at the first step. I >>> am >>> aware that you are not aware of that, because in the reply you seem >>> to >>> believe that the MEC hypothesis can be taken for granted. But it >>> can't. >> >> I think you are talking of two different machine conceptions. >> >> I would like to quote Steve Harnad: >> >> Harnad, S. Can a machine be conscious? How? Journal of Consciousness >> Studies, 2003, 10, 67-75 >> >> BEGIN: >> ...if we do follow this much more sensible route to the definition of >> "machine," we will find that a machine turns out to be simply: any >> causal physical system, any "mechanism." And in that case, biological >> organisms are machines too, and the answer to our question "Can a >> machine be conscious" is a trivial "Yes, of course." We are conscious >> machines. >> >> Hence machines can obviously be conscious. The rest is just about what >> kinds of machines can and cannot be conscious, and how -- and that >> becomes a standard empirical research program in "cognitive >> science"... >> >> END QUOTE >> >> >> I think this is the machine concept Kim was using originally (and >> maybe >> still has in mind). >> This conception can, I think, be indeed taken for granted by every >> scientifically minded person. > > > Why ? It is an assumption too. What could we taken it for granted? > And this assumption is quite close to comp in the sense that nobody > knows about > any "natural" machine not being turing emulable. Even quantum machine, > accepting QM without collapse. > > >> >> >> Bruno, on the other hand, is talking about the machine concept as it >> exists in logic: here machine/mechanism >> - and also the >> COMP(utationalism) of cognitive science - does not mean any physical >> causal system, but effective mechanisms - an informal notion >> formalised >> (according to Church-Turing Thesis) with UTM/Lambda/Rec. >> Functions. > > > All known physical causal system are Turing emulable. > > > > >> And COMP is the assumption that we are Turing-emulable (with an UTM >> for >> example), not the more trivial hypothesis that we are a physical >> causal >> system. >> >> And this (COMP), indeed, can't be taken for granted but must be >> assumed. > > > I don't see why this COMP has to be assumed, and not the other > slightly enlarged version. > Both are assumption. > > And none of KIM 2.1 (= UDA 1), nor KIM.2.3 (= UDA 3) assumes the > digitality. This is done at step 7. We used only the replicability. > > I agree that the UDA does not apply to natural machine whose function > cannot be replicated. But nobody has ever seen or even conceive such a > machine. You have to assume a non repeatable phenomenon, hard to get > from QM without collapse. That is "non comp", but I doubt Harnad > believe in such non-comp. He has to say explicitely the machine have > non replicable functions, it seems to me. I have not the paper, and if > this what he says, let me known, that would be curious and > interesting, but frankly I doubt it. If we (human) understand the > functioning of such machine, then we could compute more than a Turing > Machine, and Church thesis, in math, would be false. Why not, but this > is just saying our assumption could be wrong, but this is always true. > Harnad assumption is really comp, unless he mention explicit non > replicability, explicit non effective processes. Does it? > > Bruno > > > http://iridia.ulb.ac.be/~marchal/ > > > > > > > -- Abram Demski Public address: abram-dem...@googlegroups.com Public archive: http://groups.google.com/group/abram-demski Private address: abramdem...@gmail.com --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-l...@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 -~----------~----~----~----~------~----~------~--~---
