Re: Machines was:Kim 2.1
On 28/12/2008, at 12:14 AM, Bruno Marchal wrote: > With > Everett everything becomes clearer: nature does not collapse the wave, > and thus, does not provide any examples of a machine generating truly > random events. Randomness appears in the mind of the multiplied > observers, exactly like in the mechanical self-duplication experience. > That is why Everett and comp fits so well together. Here I feel I finally understand the kernel of comp. The outcome of any measurement is always subject to the 1 indeterminacy, which we read as "random" In fact "random" is itself a product of OUR unavoidable uncertainty, non? TRUE random would admit the white rabbits; like the dice disappearing after we throw them > > > Of course Everett could be wrong, and comp could be wrong, and > naturalism could be right: but it is up to the naturalist to say what > is the machine's atomic operation that a Turing machine cannot > complete. If it is the generation of a truly random event, and if this > is based on the wave collapse, then I can understand (but you will > have to solve all the problem raised by the collapse, you will have to > abandon the theory of relativity like Bohm and Bell suggested, etc.). > Or you say like Searle that "only special machine can think: > biological brain". If Searle (and Penrose) are right, then why not a simple biological brain transplant? Why bother with looking for "the right substitution level" at all in this case? Just pilfer a wet, messy brain from a road accident victim and shove it into your skull. But where would we now stand with respect to the indeterminacy? I asked my partner today whether she felt she would be the same person after receiving a biological brain transplant and she said "Of course not! I would now be the dead person whose brain I have inherited. Who I am is generated only by MY brain." Proves she is a materialist/ physicalist, I guess. We all know people like this. Sigh. I then asked her if she would feel herself to be the same person after a digi-brain transplant. She responded that this was maybe possible, but she felt dubious about it. Would there in fact be any difference? After all, we are assuming that wet, messy brains and digi-brains are equivalent, all things considered? > In that case we have to suppose something very > special about the brain: it generates consciousness. This made me laugh out loud. I just love it when you say things like this. Perhaps we must give up on the notion that personhood has anything at all to do with a brain? > But this is just > a blocking argument: it could be interesting only if it points on > something special in the brain that a digital machine cannot imitate. > Without such specification it is just equivalent with the *assumption* > that the brain is not a digital machine. Enter the soul, enter religion - enter the supernatural. Hummmph!! cheers, K --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
On 27 Dec 2008, at 20:50, Günther Greindl wrote: > I agree with Bruno that all empirical evidence in this universe > suggest > that CT = PCT. But this need not be so, in a logical sense. Indeed. UDA shows that PCT is a mysterious, if not *the* mystery with CT. Logicaly, and a priori, CT implies NOT PCT, or possible(not PCT). It is still an open problem, given that physics is not yet completely extracted, to say the least, from the comp hypothesis. 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-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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
Stathis, > > From the SEP article: > that a human being unaided by machinery is capable of carrying out -- > carries no implication concerning the extent of the procedures that > machines are capable of carrying out, even machines acting in > accordance with 'explicitly stated rules'. For among a machine's > repertoire of atomic operations there may be those that no human being > unaided by machinery can perform." > > Is this just being pedantic in trying to stick to what the great man > actually said? What is an example of a possible operation a machine > could perform that a human, digital computer or Turing machine would > be unable to perform? the idea is simply that the Physical Church Turing Thesis (PCT, or Thesis M in the article) is distinct from the Church Turing Thesis (CT). PCT is much stronger than CT; CT is the thesis that UTMs can compute all functions which are effective, that is, which a human being unaided by machinery (except paper and pencil) can perform. It is a thesis on the interface between "intuitive" (not Brouwer's sense) mathematics and formal logic/computability theory. PCT is the thesis that those are also the limits of machine operations in this universe - and is as such an empirical thesis. I agree with Bruno that all empirical evidence in this universe suggest that CT = PCT. But this need not be so, in a logical sense. There could be physical machines exploiting local infinities which were strictly more powerful than effective methods/CT/human beings. See for instance this paper: Copeland, B. J. & Shagrir, O. Physical Computation: How General are Gandy's Principles for Mechanisms? Minds and Machines., 2007, 17, 217-231 Abstract: What are the limits of physical computation? In his `Church's Thesis and Principles for Mechanisms', Turing's student Robin Gandy proved that any machine satisfying four idealised physical `principles' is equivalent to some Turing machine. Gandy's four principles in effect define a class of computing machines (`Gandy machines'). Our question is: What is the relationship of this class to the class of all (ideal) physical computing machines? Gandy himself suggests that the relationship is identity. We do not share this view. We will point to interesting examples of (ideal) physical machines that fall outside the class of Gandy machines and compute functions that are not Turing-machine computable. See also: http://en.wikipedia.org/wiki/Hypercomputation Read especially (at the end): "As long as there is no physically plausible way to build such a device, hypercomputers will exist only as mathematical models." I don't think that current science suggests in any way that such machines are possible. But nevertheless we shouldn't ignore the possibility. Cheers, Günther --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
Hi Kim, I'm afraid I probably don't understand your question. It seems to me you are using in an informal context some terms like if they have precise meaning. I will make a try, so as to be clearer on the point raised by Günther and Abram. On 26 Dec 2008, at 22:49, Kim Jones wrote: > > > On 27/12/2008, at 7:56 AM, Bruno Marchal wrote: > >> nd sometimes, even that is not enough, and you have to climb on the >> higher infinities. I think Kim was asking for an example of well- >> defined notions which are not effective. The existence of such non >> effective objects is not obvious at all for non mathematicians. >> >> Your interpretation was correct too given that Kim question was >> ambiguous. > > > I wanted to know if you can have: > > 1. A system with a defined set of rules but no definite description > (an electron?) Perhaps with a bit of imagination I can give sense to this. It raises an important question: can we simulate the observable behavior of an electron with a classical computer? I think that the answer is NO. For example if the electron is in a superposition state UP+DOWN, and you observe it with the {UP, DOWN} obervable, you will see it UP or DOWN with a truly random probability 1/2. It can be proved that such a truly random process cannot be simulated on a classical computer. What you can simulate with a classical computer is the coupled system PHYSICIST+ELECTRON. In that case, the result of the simulation is the MW-situation PHYSICIST UP + PHYSICIST DOWN, and the probability 1/2 comes from the fact that the physicist has been duplicated. So the probability is a first person point of view. > > > or > > 2. A system with a definite description but no rules governing it > (???) Theoretical computer science is born dues to the complexity of defining what "definite description", and "rules" can mean. Without delving more in computer science I can only point to informal example. It can be argued that the set of true propositions in Arithmetic admit a definite description. For example we can defined it easily in naïve set theory, and we can have a pretty idea of what that set consists in. But we cannot generate such a set with a computer, and it that sense there can be no rule governing it. Most set of numbers are of that type. They escape the computable realm. For example the Universal dovetailer will generate only a tiny (but very important) part of arithmetical truth, indeed, with Church thesis, it can be said it generates the whole of the computable part of arithmetic. In math there are many things that we can define and talk about, but that we cannot compute. This makes the difference between constructive or intuitionist mathematics and classical mathematics. > > > > Based on Abram's original distinction, as a way of separating the two > types of machine that Günther specified. I would be pleased if someone can explain this link. Let me quote Stathis Papaioannou: > From the SEP article: > > "Turing did not show that his machines can solve any problem that can > be solved "by instructions, explicitly stated rules, or procedures", > nor did he prove that the universal Turing machine "can compute any > function that any computer, with any architecture, can compute". He > proved that his universal machine can compute any function that any > Turing machine can compute; and he put forward, and advanced > philosophical arguments in support of, the thesis here called Turing's > thesis. But a thesis concerning the extent of effective methods -- > which is to say, concerning the extent of procedures of a certain sort > that a human being unaided by machinery is capable of carrying out -- > carries no implication concerning the extent of the procedures that > machines are capable of carrying out, even machines acting in > accordance with 'explicitly stated rules'. For among a machine's > repertoire of atomic operations there may be those that no human being > unaided by machinery can perform." > > Is this just being pedantic in trying to stick to what the great man > actually said? What is an example of a possible operation a machine > could perform that a human, digital computer or Turing machine would > be unable to perform? I probably mention such an example above: to generate a truly random event. And the old Copenhagen QM, which admits a reduction of the wave packet, could have inspired for a time the believe that nature can do that. But after Einstein-Bohr-Podolski (EPR) paper, even Bohr realised that the collapse of the wave cannot be a "mechanical" phenomenon, and most Copenhagians will have to say that the quantum wave function describe knowledge state, and not nature or physical systems. With Everett everything becomes clearer: nature does not collapse the wave, and thus, does not provide any examples of a machine generating truly random events. Randomness appears in the mind of the multiplied obse
Re: Machines was:Kim 2.1
Abram, > > Thanks for the reference. That book sounds very interesting... > unfortunately it is also very expensive. Then don't buy it. In my opinion, well to get the AUDA, the following one are without doubt more genuine. Actually I complained often that the Boolos 1979 book was out of stock and print, but I discover today that it will be published again: http://www.amazon.com/gp/product/0521092973/ref=pe_5050_10997920_pe_snp_973 That is: BOOLOS G., 1979, The Unprovability of Consistency, an Essay in Modal Logic, Cambridge University Press. It is a lighter and shorter introduction to the Godel Lob logic of self-reference used in AUDA. Lighter and fresher than its 1993 extension which tackles the first order (incomplete) self-reference logics: (which is excellent too). Boolos, G. (1993). The Logic of Provability. Cambridge University Press, Cambridge. The following one by Smorynski is quite nice too, perhaps even better on the relation with computability and the role of the sigma_1 sentences. It contains also a bit of the Magari algebraic treatment of self-reference, but the font is so small that even with spectacles I confuse the indices with the (old) tobacco stains! Smoryński, P. (1985). Self-Reference and Modal Logic. Springer Verlag, New York. If you buy only one, buy the 1993 Boolos one. I hope they are less expensive, high price for math books is a pity and shame. There is also the "recreative" one by Raymond Smullyan, which I find very interesting. It is a must! It should not be expensive. Buy the "penguin" edition you will find on amazon (the Knopf edition is quite cute but less cheap). Smullyan, R. (1987). Forever Undecided. Knopf, New York. Bruno On 26 Dec 2008, at 21:38, Abram Demski wrote: > > Bruno, > > Thanks for the reference. That book sounds very interesting... > unfortunately it is also very expensive. > > --Abram > > On Thu, Dec 25, 2008 at 1:23 PM, Bruno Marchal > wrote: >> >> >> >> POUR-EL M. B., RICHARD J. I., 1989, Computability in Analysis and >> Physics, >> Springer-Verlag, Berlin. >> >> 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 > > > 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-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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
On 27/12/2008, at 7:56 AM, Bruno Marchal wrote: > nd sometimes, even that is not enough, and you have to climb on the > higher infinities. I think Kim was asking for an example of well- > defined notions which are not effective. The existence of such non > effective objects is not obvious at all for non mathematicians. > > Your interpretation was correct too given that Kim question was > ambiguous. I wanted to know if you can have: 1. A system with a defined set of rules but no definite description (an electron?) or 2. A system with a definite description but no rules governing it (???) Based on Abram's original distinction, as a way of separating the two types of machine that Günther specified. My intuition says you can have 1 but maybe not 2. I am struggling here maybe badly... Most systems of course have both. Arithmetical reality surely has rules but I'm wondering about the description? Maybe it is the candidate as Bruno suggests? cheers, K --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
On 26 Dec 2008, at 20:24, Abram Demski wrote: > > Bruno, > > In one sense those examples are things for which (finite) reasoning > fails, but I would still say that they are governed by (finite) rules > and possess a (finite) description-- Yes but we have to bet we share the standard interpretation of it. And the notion of finiteness itself cannot de described in a finite way. Then things get more complex and need higher infinities to be described. > the problem is "merely" that it > takes infinite amounts of time to derive the consequences of those > rules/descriptions. And sometimes, even that is not enough, and you have to climb on the higher infinities. I think Kim was asking for an example of well- defined notions which are not effective. The existence of such non effective objects is not obvious at all for non mathematicians. Your interpretation was correct too given that Kim question was ambiguous. The real question is what does this have to do with Günther's proposal that we should distinguish natural or physical machine from the digital machine, unless it is followed by an explanation why such machines should say no to the doctor. I mean when you said: <> To escape or criticize the consequences of the UDA, you have to say explicitly in what sense those natural machines are not Turing emulable, or why they have to say no to the doctor. I have nothing against non-computationalism, but I am not convinced by any who points on nature. Nature, it seems to me, behave as if it has already bet on comp more than one times. Our cells bet on self- replication all the times, and they substitute their functional components more quickly than current machines. And the nervous systems appears when chatty amoebas discovered the cables. Universality is cheap. The "scientifically minded person" of today take for granted both mechanism and materialism, I'm afraid. I point on the difficulties and the general shape of the solution. I warn against the risk of eliminating the person for "saving" the MAT. (In Europa and Africa we have idea about what that could mean). The universal dovetailer dovetails on the reals and the oracles too, so, to escape comp with "hypercomp" sort of weakening of mechanism does not really work, most of the self-reference logic remains stable on it. Yet, you can invoke some tools for escaping comp, but it is highly difficult to do that and being confident in the consistency of the theory. This is like constructing a magical nature, just to say no to the doctor. And then, is it not wonderful? The theory of everything can assume just the positive integers with succession, addition and multiplication. It does not eliminate the persons and it justifies the logical evolution of the physical laws so that we can measure our degree of "mechanism", in a sense. With Everett QM, it seems to me that nature confirms again the "disturbing?" consequence of Mechanism, which is that propensity to self-multiply. Bruno > > > --Abram > > On Fri, Dec 26, 2008 at 11:49 AM, Bruno Marchal > wrote: >> >> >> On 25 Dec 2008, at 22:27, Kim Jones wrote: >> >>> >>> >>> On 26/12/2008, at 5:23 AM, Bruno Marchal wrote: >>> On 25 Dec 2008, at 08:05, Abram Demski wrote: > > 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. Then Church thesis entails it is not broader, unless you mean that the rules are not effective. >>> >>> I might be missing something here, but somebody please give an >>> example >>> of a system that is NOT governed by rules and possesses NO definite >>> description. >> >> Arithmetical truth. That is, the set of all true sentences of >> elementary arithmetic. >> The set of Gödel number, or description of never stopping programs or >> machines. >> The set of descriptions (in any universal language) of any non >> trivial >> machines. >> At the first order level: all the arithmetical hypostases. >> Sigma_2 truth, Sigma_3 truth, Sigma_4 truth, Sigma_5 truth, Sigma_6 >> truth, etc. (the union of which gives arithmetical truth) >> Analytical truth (far beyond arithmetical truth). >> Mathematical Truth (if that exists). >> >> Kim, all those exemples provide well defined set of objects, (except >> the last one) but there is no way to generate them by any machine, >> nor >> can we axiomatize them in any effective way. No effective complete >> "Theory" for any of them. >> >> Alas, there is a need of some math to prove this. If you are patient, >> when we get the seven step of UDA, I will have to give you at least a >> tool (diagonalization) capable of easily showing the existence and >> the >> non effectivity of those non mechanical mathematical realities. >> >> It is needed to be more precise on "ef
Re: Machines was:Kim 2.1
Bruno, Thanks for the reference. That book sounds very interesting... unfortunately it is also very expensive. --Abram On Thu, Dec 25, 2008 at 1:23 PM, Bruno Marchal wrote: > > On 25 Dec 2008, at 08:05, Abram Demski wrote: > > 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. > > Then Church thesis entails it is not broader, unless you mean that the rules > are not effective. > > > 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). > > UDA still works with very big weakening of comp, which I don't mention > usually for pedagogical purpose. The fact that the first person cannot be > aware of delays, together with the fact that the UD generates the reals > extend the comp consequences to machine with all kind of oracles. > The AUDA is even less demanding, and works for highly non effective notion > of "belief". Instead of using the Gödel provability predicate we can use non > effective notion like "truth in all model of ZF", or even "truth in all > transitive models of ZF". In that last case G and G* can be effectively > extended. > To my knowledge the only scientist being explicitly non mechanist is > Penrose. Even Searle who pretends to be a non mechanist appears to refer to > machine, for the brain, which are Turing emulable. Then Searles make error > in its conception of "mind implementation" and "simulation" like Hofstadter > and Dennett have already very well criticized. The comp reasoning begins to > be in trouble with machines using discrete set of actual infinities. Analog > machine based on notion of interval are mostly Turing emulable. You have to > diagonalize or use other logical tools in some sophisticate way to build > analytical machine which are non turing emulable. Nothing in physics or in > nature points on the existence of those "mathematical weirdness", with the > notable "collapse of the wave packet" (exploited by Penrose, but also by > many dualists). > > > > > The narrower type of machine is restricted to be computable. > > It is logically narrower. But no weakening of comp based on nature is known > to escape the replicability. Even the non cloning theorem in QM cannot be > used to escape the UDA conclusion. You have to introduce explicit use of > actual infinities. This is very akin to a "substantialisation" of soul. I > respect that move, but I have to criticize unconvincing motivations for it. > Comp entails the existence of uncomputable observable phenomena. It is > normal to be attracted to the idea that non computability could play a role > in the mind. But this consists to build a machine based on the many sharable > computations going through the turing state of the machine and this gives > "quantum machine", which are turing emulable although not in real time, but > then they play their role in the Universal Deployment. > Of course you can just say "NO" to the doctor. But by invoking a non turing > emulable "machine", you take the risk of being asked which one. Up to now, > as far as I know, this exists in mathematics, but there are no evidence it > exists in nature, except those using the kind of indeterminacy which can be > explain with the comp hypothesis. > > > > 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. > > The SWE is linear. It makes the quantum object directly turing emulable > (mostly by dovetailing if you are using a sequential processor). The > solution are linear combination of complex exponential. Obviously e, PI and > i are computable reals. > It is far more difficult, and perhaps false, to say that Newtonian Physics > is Turing emulable. Newton himself was aware of action at a distance for its > gravitational law. But anything so weird has been usually considered as an > evidence that Newtonian Physics could not be taken literaly. > To reintroduce such bizarre feature in nature just to contradict the comp > hyp is a bit ironical. It is like Bohmian reformulation of Quantum > Mechanics: to make a theory more complex to avoid interpretation judged as > unpleasant. > This subject is made difficult because there are no standard notion of > computability with the real numbers (despite many attempts to find one). > If someone know better ... Non comp theories have to be rather exotic. Of > course this is not an argument for the truth of comp. > > I know that, > for example, Wolfram is attempting a computable foundation for > physics, but
Re: Machines was:Kim 2.1
Bruno, In one sense those examples are things for which (finite) reasoning fails, but I would still say that they are governed by (finite) rules and possess a (finite) description-- the problem is "merely" that it takes infinite amounts of time to derive the consequences of those rules/descriptions. --Abram On Fri, Dec 26, 2008 at 11:49 AM, Bruno Marchal wrote: > > > On 25 Dec 2008, at 22:27, Kim Jones wrote: > >> >> >> On 26/12/2008, at 5:23 AM, Bruno Marchal wrote: >> >>> >>> On 25 Dec 2008, at 08:05, Abram Demski wrote: >>> 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. >>> >>> Then Church thesis entails it is not broader, unless you mean that >>> the rules are not effective. >>> >>> >>> >> >> I might be missing something here, but somebody please give an example >> of a system that is NOT governed by rules and possesses NO definite >> description. > > Arithmetical truth. That is, the set of all true sentences of > elementary arithmetic. > The set of Gödel number, or description of never stopping programs or > machines. > The set of descriptions (in any universal language) of any non trivial > machines. > At the first order level: all the arithmetical hypostases. > Sigma_2 truth, Sigma_3 truth, Sigma_4 truth, Sigma_5 truth, Sigma_6 > truth, etc. (the union of which gives arithmetical truth) > Analytical truth (far beyond arithmetical truth). > Mathematical Truth (if that exists). > > Kim, all those exemples provide well defined set of objects, (except > the last one) but there is no way to generate them by any machine, nor > can we axiomatize them in any effective way. No effective complete > "Theory" for any of them. > > Alas, there is a need of some math to prove this. If you are patient, > when we get the seven step of UDA, I will have to give you at least a > tool (diagonalization) capable of easily showing the existence and the > non effectivity of those non mechanical mathematical realities. > > It is needed to be more precise on "effectivity" to discover the non- > effectivity. > Mechanism is not a reductionism, (as I explain often to John Mikes) > because Universal machines behaviors depends on those non effective > things. Creation and life appears on the border between the computable > and the non computable. It is similar to the border of the Mandelbrot > set. > > 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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
On 25 Dec 2008, at 22:27, Kim Jones wrote: > > > On 26/12/2008, at 5:23 AM, Bruno Marchal wrote: > >> >> On 25 Dec 2008, at 08:05, Abram Demski wrote: >> >>> >>> 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. >> >> Then Church thesis entails it is not broader, unless you mean that >> the rules are not effective. >> >> >> > > I might be missing something here, but somebody please give an example > of a system that is NOT governed by rules and possesses NO definite > description. Arithmetical truth. That is, the set of all true sentences of elementary arithmetic. The set of Gödel number, or description of never stopping programs or machines. The set of descriptions (in any universal language) of any non trivial machines. At the first order level: all the arithmetical hypostases. Sigma_2 truth, Sigma_3 truth, Sigma_4 truth, Sigma_5 truth, Sigma_6 truth, etc. (the union of which gives arithmetical truth) Analytical truth (far beyond arithmetical truth). Mathematical Truth (if that exists). Kim, all those exemples provide well defined set of objects, (except the last one) but there is no way to generate them by any machine, nor can we axiomatize them in any effective way. No effective complete "Theory" for any of them. Alas, there is a need of some math to prove this. If you are patient, when we get the seven step of UDA, I will have to give you at least a tool (diagonalization) capable of easily showing the existence and the non effectivity of those non mechanical mathematical realities. It is needed to be more precise on "effectivity" to discover the non- effectivity. Mechanism is not a reductionism, (as I explain often to John Mikes) because Universal machines behaviors depends on those non effective things. Creation and life appears on the border between the computable and the non computable. It is similar to the border of the Mandelbrot set. 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-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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
On 25 Dec 2008, at 20:10, Günther Greindl wrote: > > Bruno, > >> But no weakening of comp based on nature is >> known to escape the replicability. Even the non cloning theorem in QM >> cannot be used to escape the UDA conclusion. > > I already wanted to ask you on this one: you have said before on the > list that quantum-no cloning does not make a problem (and I agree in a > logical sense). > > But practically, do you mean that from no cloning we can infer that > our > subsitution level must be _above_ the quantum level? I think you are correct. 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-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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
Hi Günther, On 25 Dec 2008, at 20:01, Günther Greindl wrote: > > Bruno, > >>> 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? > > Yes, it is an assumption - that is why is wrote "scientifically > minded" > - if you are in any way naturalist (and all the more if you are > materialist), then you can assume the above. I would say that a scientific mind don't take anything for granted, especially when very big problem are still unsolved. The little progress I try to describe shows that most scientist are wrong on the mind body question, and actually even only on the matter question. > > >> 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. > > That is true, but we have to be careful in our reasoning. > > Look at Thesis M: > > http://plato.stanford.edu/entries/church-turing/#Bloopers > > That is quite different from CT. And while the two may be identical in > the real world (empirical question), they are logically distinct. That link does not define "machine" and I don't know what he talks about. It described confusing misunderstandings of Church thesis, but his comments are even more confusing, and some does not make any sense if we take the UD Argument into account. If by machine, the paper means "physical machine", then COMP implies stricto senso that the thesis M is false. COMP implies that the observable physical vacuum is already not Turing emulable (as opposed to the multiverse description of the vacuum, which of course does not belongs to the observable realm (we can't step out of the multiverse). > > (and, as you can read in the article, hypercomp would refute comp, Not at all. But this would be a technical digression. We could come back when I am sure most get the UDA point. > > showing that logical distinction remains even if we can let them > coincide in this universe). > >> All known physical causal system are Turing emulable. > > Yes - "known". There could be others (I don't believe it, but there > could). > >> I don't see why this COMP has to be assumed, and not the other >> slightly enlarged version. >> Both are assumption. > > Agreed - but many more scientists will be prepared to assume the first > and not COMP. It is simply the difference between materialism and > computationalism, and most natural scientists are materialists. Most are both computationalist and materialist. UDA shows that they are wrong. > > >> 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. > > ok, no problem. Just wanted to clear up terminology. > >> 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. > > Indeed - it would for instance be Penrose style Quantum grav 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. > > Harnad does not clarify further in the paper which version he > endorses - > the quote was just very nice to introduce a physcial version of CT > (thesis M). OK. Just remember that a priori comp makes the thesis M wrong. 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-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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
2008/12/26 Günther Greindl wrote: >> 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. > > That is true, but we have to be careful in our reasoning. > > Look at Thesis M: > > http://plato.stanford.edu/entries/church-turing/#Bloopers > > That is quite different from CT. And while the two may be identical in > the real world (empirical question), they are logically distinct. > (and, as you can read in the article, hypercomp would refute comp, > showing that logical distinction remains even if we can let them > coincide in this universe). > >> All known physical causal system are Turing emulable. > > Yes - "known". There could be others (I don't believe it, but there could) From the SEP article: "Turing did not show that his machines can solve any problem that can be solved "by instructions, explicitly stated rules, or procedures", nor did he prove that the universal Turing machine "can compute any function that any computer, with any architecture, can compute". He proved that his universal machine can compute any function that any Turing machine can compute; and he put forward, and advanced philosophical arguments in support of, the thesis here called Turing's thesis. But a thesis concerning the extent of effective methods -- which is to say, concerning the extent of procedures of a certain sort that a human being unaided by machinery is capable of carrying out -- carries no implication concerning the extent of the procedures that machines are capable of carrying out, even machines acting in accordance with 'explicitly stated rules'. For among a machine's repertoire of atomic operations there may be those that no human being unaided by machinery can perform." Is this just being pedantic in trying to stick to what the great man actually said? What is an example of a possible operation a machine could perform that a human, digital computer or Turing machine would be unable to perform? -- Stathis Papaioannou --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
Kim, Right, that can't be done-- maybe such a system exists, but if so then our rationality basically fails to apply to it. So as Gunther says, the broader version of mechanism "can be granted by every scientifically minded person". --Abram On Thu, Dec 25, 2008 at 4:27 PM, Kim Jones wrote: > > > On 26/12/2008, at 5:23 AM, Bruno Marchal wrote: > >> >> On 25 Dec 2008, at 08:05, Abram Demski wrote: >> >>> >>> 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. >> >> Then Church thesis entails it is not broader, unless you mean that >> the rules are not effective. >> >> >> > > I might be missing something here, but somebody please give an example > of a system that is NOT governed by rules and possesses NO definite > description. > > cheers, > > K > > > > > > -- 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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
On 26/12/2008, at 5:23 AM, Bruno Marchal wrote: > > On 25 Dec 2008, at 08:05, Abram Demski wrote: > >> >> 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. > > Then Church thesis entails it is not broader, unless you mean that > the rules are not effective. > > > I might be missing something here, but somebody please give an example of a system that is NOT governed by rules and possesses NO definite description. cheers, K --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
Bruno, > But no weakening of comp based on nature is > known to escape the replicability. Even the non cloning theorem in QM > cannot be used to escape the UDA conclusion. I already wanted to ask you on this one: you have said before on the list that quantum-no cloning does not make a problem (and I agree in a logical sense). But practically, do you mean that from no cloning we can infer that our subsitution level must be _above_ the quantum level? Cheers, Günther --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
Bruno, >> 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? Yes, it is an assumption - that is why is wrote "scientifically minded" - if you are in any way naturalist (and all the more if you are materialist), then you can assume the above. > 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. That is true, but we have to be careful in our reasoning. Look at Thesis M: http://plato.stanford.edu/entries/church-turing/#Bloopers That is quite different from CT. And while the two may be identical in the real world (empirical question), they are logically distinct. (and, as you can read in the article, hypercomp would refute comp, showing that logical distinction remains even if we can let them coincide in this universe). > All known physical causal system are Turing emulable. Yes - "known". There could be others (I don't believe it, but there could) > I don't see why this COMP has to be assumed, and not the other > slightly enlarged version. > Both are assumption. Agreed - but many more scientists will be prepared to assume the first and not COMP. It is simply the difference between materialism and computationalism, and most natural scientists are materialists. > 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. ok, no problem. Just wanted to clear up terminology. > 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. Indeed - it would for instance be Penrose style Quantum grav 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. Harnad does not clarify further in the paper which version he endorses - the quote was just very nice to introduce a physcial version of CT (thesis M). Cheers, Günther --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Re: Machines was:Kim 2.1
On 25 Dec 2008, at 08:05, Abram Demski wrote: > > 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. Then Church thesis entails it is not broader, unless you mean that the rules are not effective. > 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). UDA still works with very big weakening of comp, which I don't mention usually for pedagogical purpose. The fact that the first person cannot be aware of delays, together with the fact that the UD generates the reals extend the comp consequences to machine with all kind of oracles. The AUDA is even less demanding, and works for highly non effective notion of "belief". Instead of using the Gödel provability predicate we can use non effective notion like "truth in all model of ZF", or even "truth in all transitive models of ZF". In that last case G and G* can be effectively extended. To my knowledge the only scientist being explicitly non mechanist is Penrose. Even Searle who pretends to be a non mechanist appears to refer to machine, for the brain, which are Turing emulable. Then Searles make error in its conception of "mind implementation" and "simulation" like Hofstadter and Dennett have already very well criticized. The comp reasoning begins to be in trouble with machines using discrete set of actual infinities. Analog machine based on notion of interval are mostly Turing emulable. You have to diagonalize or use other logical tools in some sophisticate way to build analytical machine which are non turing emulable. Nothing in physics or in nature points on the existence of those "mathematical weirdness", with the notable "collapse of the wave packet" (exploited by Penrose, but also by many dualists). > > > The narrower type of machine is restricted to be computable. It is logically narrower. But no weakening of comp based on nature is known to escape the replicability. Even the non cloning theorem in QM cannot be used to escape the UDA conclusion. You have to introduce explicit use of actual infinities. This is very akin to a "substantialisation" of soul. I respect that move, but I have to criticize unconvincing motivations for it. Comp entails the existence of uncomputable observable phenomena. It is normal to be attracted to the idea that non computability could play a role in the mind. But this consists to build a machine based on the many sharable computations going through the turing state of the machine and this gives "quantum machine", which are turing emulable although not in real time, but then they play their role in the Universal Deployment. Of course you can just say "NO" to the doctor. But by invoking a non turing emulable "machine", you take the risk of being asked which one. Up to now, as far as I know, this exists in mathematics, but there are no evidence it exists in nature, except those using the kind of indeterminacy which can be explain with the comp hypothesis. > > >> >> 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. The SWE is linear. It makes the quantum object directly turing emulable (mostly by dovetailing if you are using a sequential processor). The solution are linear combination of complex exponential. Obviously e, PI and i are computable reals. It is far more difficult, and perhaps false, to say that Newtonian Physics is Turing emulable. Newton himself was aware of action at a distance for its gravitational law. But anything so weird has been usually considered as an evidence that Newtonian Physics could not be taken literaly. To reintroduce such bizarre feature in nature just to contradict the comp hyp is a bit ironical. It is like Bohmian reformulation of Quantum Mechanics: to make a theory more complex to avoid interpretation judged as unpleasant. This subject is made difficult because there are no standard notion of computability with the real numbers (despite many attempts to find one). If someone know better ... Non comp theories have to be rather exotic. Of course this is not an argument for the truth of comp. > 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. Wolfram like Schmidhuber believes there could be a computable universe. The "whole" could be computable. But in t
Re: Machines was:Kim 2.1
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 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
Re: Machines was:Kim 2.1
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/ --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Machines was:Kim 2.1
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. 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. 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. Happy Holidays, Günther --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---