Re: Teleportation thought experiment and UD+ASSA
Hal, thanks for explaining! I think that your approach makes a lot of sense. Applying this to copying experiments, the probability of finding yourself to be the digital copy is: m1/[m1 + m2] where m1 is the measure of the mental experience corresponding to knowing that you are the digital copy and m2 the measure of the mental experience corresponding to knowing that you are still in biological form. I think that for practical implementations m1 = m2 because the digital implementation will just simulate the brain, so the complexity of the translation program would be practically the same. Saibal - Original Message - From: Hal Finney [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Wednesday, June 21, 2006 08:49 AM Subject: Re: Teleportation thought experiment and UD+ASSA Saibal Mitra [EMAIL PROTECTED] writes: I don't understand why you consider the measures of the programs that do the simulations. The ''real'' measure should be derived from the algorithmic complexity of the laws of physics that describe how the computers/brains work. If you know for certain that a computation will be performed in this universe, then it doesn't matter how it is performed. I think what you're saying here is that if a mental state is instantiated by a given universe, the contribution to its measure should just be the measure of the universe that instantiates it. And that universe's measure is based on the complexity of its laws of physics. I used to hold this view, but I eventually abandoned it because of a number of problems. I need to go back and collect the old messages and discussions that we have had and put them into some kind of order. But I can mention a couple of issues. One problem is the one I just wrote about in my reply to Russell, the fuzziness of the concept of implementation. In at least some universes we may face a gray area in deciding whether a particular computation, or more specifically a particular mental state, is being instantiated. Philosophers like Hans Moravec apparently really believe that every system instantiates virtually every mental state! If you look at the right subset of the atomic vibrations inside a chunk of rock, you can come up with a pattern that is identical to the pattern of firing of neurons in your own brain. Now, most philosophers reject this, they come up with various technical criteria that implementations have to satisfy, but as I wrote to Russell I don't think any of these work. The other problem arises from fuzziness in what counts as a universe. The problem is that you can write very simple programs which will create your mental state. For example, the Universal Dovetailer does just that. But the UD program is much smaller than what our universe's physical laws probably would be. Does the measure of the UD count as a contribution to every mind it creates? If so, then it will dominate over the contributions from more conventional universes; and further, since the UD generates all minds, it means that all minds have equal measure. To reject the UD as a cheating non-universe means that we will need a bunch of ad hoc rules about what counts as a universe and what does not, which are fundamentally arbitrary and unconvincing. Then there are all those bothersome disputes which arise in this model, such as whether multiple instantiations should add more measure than just one; or whether a given brain in a small universe should get more measure than the same brain in a big universe (since it uses a higher proportion of the universe's resources in the first case). All these issues, as well as the ones above, are addressed and answered in my current framework, which is far simpler (the measure of a mental state is just its Kolmogorov measure - end of story). The algorithmic complexity of the program needed to simulate a brain refers to a ''personal universe''. You can think of the brain as a machine that is simulating a virtual world in which the qualia we experience exist. That world also exists independent of our brain in a universe of its own. This world has a very small measure defined by the very large algorithmic complexity of the program needed to specify the brain. I agree with this, I think. The program needed to specify a mental state a priori would be far larger than the program needed to specify the laws of physics which could cause that mental state to evolve naturally. Both programs make a contribution to the measure of the mental state, but the second one's contribution is enormously greater. The key point, due to Wei Dai, is that you can mathematically treat the two on an equal footing. As you have described it, we have a virtual world with qualia being created by a brain; and you have that same world existing independently as a universe of its own. Those are pretty different in a Schmidhuber type model. The second case is the output of one
RE: Re: Teleportation thought experiment and UD+ASSA
Hal Finney writes: The problem is that there seems to be no basis for judging the validity of this kind of analysis. Do we die every instant? Do we survive sleep but not being frozen? Do we live on in our copies? Does our identity extend to all conscious entities? There are so many questions like this, but they seem unanswerable. And behind all of them lurks our evolutionary conditioning forcing us to act as though we have certain beliefs, and tricking us into coming up with logical rationalizations for false but survival-promoting beliefs. There is a way around some of these questions. When I ask whether my copy produced as a result of teleportation, or whatever, will really be me, what I want to know is whether that copy will subjectively stand in the same relationship to me as I stand now in relationship to my self of a moment ago. It doesn't really matter to me what process I go through (provided that the process does not have other unpleasant side-effects, of course) as long as this is the end result. In fact, I am quite happy with the notion that I live only transiently, because it does away with all the paradoxes of personal identity. Normal life then consists in the relationship between these transient selves: that they have certain thoughts in a certain temporal sequence, memories of previous selves, a sense of identity persisting through time, and so on. While it is true that in the world with which we are all familiar this sequence of selves is implemented in a single organism living its life from birth to death, there is no logical reason why this has to be so; and if you consider that there may not be a single atom in your body today that was there a year ago, physical continuity over time is just an illusion anyway. Even if it were possible to imagine another way of living my life which did not entail dying every moment, for example if certain significant components in my brain did not turn over, I would not expend any effort to bring this state of affairs about, because if it made no subjective or objective difference, what would be the point? Moreover, there would be no reason for evolution to favour this kind of neurophysiology unless it conferred some other advantage, such as greater metabolic efficiency. Right, so there are two questions here. One is whether there could be reasons to prefer a circumstance which seemingly makes no objective or subjective difference. I'll say more about this later, but for now I'll just note that it is often impossible to know whether some change would make a subjective difference. Yes, it does present difficulties, not least because we haven't managed to duplicate a person yet and there is no experimental data! But it wouldn't be fair to insist, if we did do the experiment, that we can't really know the subject's first person experience, because the same criticism could be made of any situation with a human subject. For example, we could say that we can't be sure someone who has had transient loss of consciousness is the same person afterwards, despite their insistence that they feel the same, because it is impossible to know what they are actually feeling, and even if we relied on their verbal account, we could not be sure that they have an accurate memory of what they were like before the incident. The other question is whether we could or should even try to overcome our evolutionary programming. If evolution doesn't care if we die once we have reproduced, should we? If evolution tells us to sacrifice ourselves to save two children, eight cousins, or 16 great-great uncles, should we? In the long run, we might be forced to obey the instincts built into us by genes. But it still is interesting to consider the deeper philosophical issues, and how we might hypothetically behave if we were free of evolutionary constraints. I was actually trying to make a different point. If the subject undergoing teleportation does not have his identity preserved, as opposed to what would have happened if he had continued living life normally, then this means that - despite his behaviour being the same and despite his insistence that he feels the same - some subtle change or error was introduced as a result of the teleportation. Since the matter in a person's body is turning over all the time, there is a constant risk of introducing copying errors as the various cellular components (including neuronal components) are replaced. Those errors that would have a negative impact on the organism's survival chances are weeded out by evolution, while those that make no difference at all remain. The putative errors introduced by teleportation are of a type which, at the very least, do not change the subjects external behaviour, even though they result in the non-preservation of personal identity (whatever that might mean). Now, even though it might be argued that teleportation-induced
Re: Teleportation thought experiment and UD+ASSA
Le 20-juin-06, à 08:47, Hal Finney a écrit : I'll offer my thoughts on first-person indeterminacy. This is based on Wei Dai's framework which I have called UD+ASSA. I guess you mean your UDist here. I am working on some web pages to summarize the various conclusions I have drawn from this framework. (Actually, here I am going to in effect use the SSA rather than the ASSA, i.e. I will work not with observer-moments but with entire observer lifetimes. But the same principles apply.) Why? How? This is not obvious, and in some context even not consistent. Let us consider Bruno's example where you are annihilated in Brussels and then copies of your final state are materialized in Washington and Moscow, and allowed to continue to run. What can we say about your subjective first-person expectations in this experiment? Here is how I would approach the problem. It is a very straightforward computational procedure (in principle). I don't think so. See below. Consider any hypothetical subjective, first person stream of consciousness. This would basically be a record of the thoughts and experiences of a hypothetical observer. Let us assume that this can be written and recorded in some form. OK. I would add that such a record is annihilated in personal use of teleportation. If not you can no more distinguish it from a third person record. Perhaps it is a record of neural firing patterns over the course of the observer's lifetime, This hides some ambiguity. neural firing pattern does not typically belongs to first person experience (unlike pain pleasure ...). or perhaps a more compressed description based on such information. ? (such a compression has nothing to do with the experience, so I don't understand). The question I would aim to answer is this: for any proposed, hypothetical first-person lifetime stream of consciousness, how much measure does this hypothetical subjective lifetime acquire from the third-person events in the universe? Which universe? And how do you link first person experience and third person description. You are talking like if the mind body problem was solved. The answer is very simple: it is the conditional Kolmogorov measure of the subjective lifetime record, given the universe as input. (Conditional) Kolmogorov measure is not computable (even in principle) unless you have an oracle for the halting problem. It is well defined, and does not depend on the chosen Universal machine (except for a constant), but it is not computable. Still it is computable in the limit, but for using that feature, you need to take into account the invariance for delays in reconstitutions, but this changes the whole frame of reasoning. I am not sure I can figure out what do you mean by universe here, nor how could a universe be an input (nor an output actually). In other words, consider the shortest program which, given the universe as input, produces that precise subjective lifetime record as output; There is no algorithm for finding that shortest programs. (part of the price of Church thesis like in the diagonalization posts). if the length of that program is L, then this universe contributes 1/2^L to the measure of that subjective lifetime. Note that I am not trying to start from the universe and decide what the first-person stream of consciousness is; rather, I compute the numerical degree to which the universe instantiates any first-person stream of consciousness. However, this does in effect answer the first question, since we can consider all possible streams of consciousness, and determine which one(s) the universe mostly adds measure to. Only with an oracle for the halting problem. Still, I don't understand what you mean (in this context) by this universe. Also, minimal complexity is a prior akin to ... classical physics. Even quantum mechanician does not really need it, because they can derive such minimization from the quantum phase randomization, as Feynman discovered (see a concise explanation of this in my 2001 paper Computation, Consciousness and the Quantum (cf url below)). These would be the ones that we would informally say that the universe instantiates. Now, let me illustrate how this would be applied to the situation in question, and some other thought experiments. Specifically, let us imagine three hypothetical streams of consciousness: B goes through life until the moment the subject is annihilated in Brussels, then stops. W goes through life as does B but continues with the life experiences from Washington. And M is like W, going through life until the event in Brussels but then continuing with the events in Moscow. Normally we only consider first-person experiences like M and W when we discuss this experiment, where the consciousness jumps to Moscow or Washington respectively, but it is also useful to consider B, which corresponds to
Re: Teleportation thought experiment and UD+ASSA
Le 21-juin-06, à 08:49, Hal Finney a écrit (to Saibal Mitra): snip and further, since the UD generates all minds, it means that all minds have equal measure. Never underestimate the basic fundamental stupidity of the UD. The UD execution is very redundant and the measure will be relative. Unless you bet on ASSA in this context, but this does not make sense (cf our older discussion). And from this we conclude that the contribution of a universe to the measure of a conscious experience is not the universe's measure itself, but that measure reduced by the measure of the program which outputs that conscious experience given the universe data as input. As far as I can make sense of the universe as data is it not a Relative SSA? As for the question above about the Universal Dovetailer universe, it is easily solved in this framework. The output of the UD is of essentially no help in producing the mental state in question, because the ouput is so enormous I think it is misleading to talk of any output of the UD. I guess you mean the computations or execution (material or not) of the UD. and we would have no idea where to look. But from the first person point of view there is no need to know where to look. Hence the UD does not make a dominant contribution to mental state measure and we avoid the paradox without any need for ad hoc rules. I would say simply that the UD is just a frame from which internal relative measure occurs. So, indeed the UD itself has no genuine measure attributed to it. This could be otherwise for some internal (perhaps quantum) universal dovetailer. 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Teleportation thought experiment and UD+ASSA
Hal, Here I agree with everything you say. Functionalism presupposes computationalism, but computationalism makes computationalism false. exit functionnalism. Even maudlin makes the confusion. I repeat that both thought experiments and Godel's incompleteness show that if we are machine then we cannot know which machine we are, nor can we know for sure our substitution level. We can bet empirically (and religiously!) only. We can deduce also that our experiences supervene on the continuum of computational histories appearing below our substitution level (those comp histories that we cannot distinguish). This explain qualitatively quantum facts, i.e. why matter will behave like if it was emerging from an infinity of parallel computations. Now I cannot take seriously the Mallah-Chalmers problem of rock instantiating finite state automata, given that with comp consciousness arises from the possible behavior of an infinity of non finite state automata (universal machine). Mallah-Chalmers are adding a naïve solution of the mind body problem (where mind are attached to concrete computations) on a naïve, aristotelian, view of matter which already contradict comp (by UDA). Bruno Le 21-juin-06, à 08:11, Hal Finney a écrit : Russell Standish [EMAIL PROTECTED] writes: On Tue, Jun 20, 2006 at 09:35:12AM -0700, Hal Finney wrote: I think that one of the fundamental principles of your COMP hypothesis is the functionalist notion, that it does not matter what kind of system instantiates a computation. However I think this founders on the familiar paradoxes over what counts as an instantiation. In principle we can come up with a continuous range of devices which span the alternatives from non-instantiation to full instantiation of a given computation. Without some way to distinguish these, there is no meaning to the question of when a computation is instantiated; hence functionalism fails. I don't follow your argument here, but it sounds interesting. Could you expand on this more fully? My guess is that ultimately it will depend on an assumption like the ASSA. I am mostly referring to the philosophical literature on the problems of what counts as an instantiation, as well as responses considered here and elsewhere. One online paper is Chalmers' Does a Rock Implement Every Finite-State Automaton?, http://consc.net/papers/rock.html. Jacques Mallah (who seems to have disappeared from the net) discussed the issue on this list several years ago. Now, Chalmers (and Mallah) claimed to have a solution to decide when a physical system implements a calculation. But I don't think they work; at least, they admit gray areas. In fact, I think Mallah came up with the same basic idea I am advocating, that there is a degree of instantiation and it is based on the Kolmogorov complexity of a program that maps between physical states and corresponding computational states. For functionalism to work, though, it seems to me that you really need to be able to give a yes or no answer to whether something implements a given calculation. Fuzziness will not do, given that changing the system may kill a conscious being! It doesn't make sense to say that someone is sort of there, at least not in the conventional functionalist view. A fertile source of problems for functionalism involves the question of whether playbacks of passive recordings of brain states would be conscious. If not (as Chalmers and many others would say, since they lack the proper counterfactual behavior), this leads to a machine with a dial which controls the percentage of time its elements behave according to a passive playback versus behaving according to active computational rules. Now we can turn the knob and have the machine gradually move from unconsciousness to full consciousness, without changing its behavior in any way as we twiddle the knob. This invokes Chalmers' fading qualia paradox and is again fatal for functionalism. Maudlin's machines, which we have also mentioned on this list from time to time, further illustrate the problems in trying to draw a bright line between implementations and clever non-implementations of computations. In short I view functionalism as being fundamentally broken unless there is a much better solution to the implementation question than I am aware of. Therefore we cannot assume a priori that a brain implementation and a computational implementation of mental states will be inherently the same. And I have argued in fact that they could have different properties. Hal Finney 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 [EMAIL PROTECTED] For more options,
RE: Re: Teleportation thought experiment and UD+ASSA
Stathis Papaioannou [EMAIL PROTECTED] writes: OK, I think I'm clear on what you're saying now. But suppose I argue that I will not survive the next hour, because the matter making up my synapses will have turned over in this time. To an outside observer the person taking my place would seem much the same, and if you ask him, he will share my memories and he will believe he is me. However, he won't be me, because I will by then be dead. Is this a valid analysis? My view is that there is a sense in which it *is* valid, but that it doesn't matter. What matters to me in survival is that there exist a person in an hour from now who by the usual objective and subjective criteria we use identifies as being me. The problem is that there seems to be no basis for judging the validity of this kind of analysis. Do we die every instant? Do we survive sleep but not being frozen? Do we live on in our copies? Does our identity extend to all conscious entities? There are so many questions like this, but they seem unanswerable. And behind all of them lurks our evolutionary conditioning forcing us to act as though we have certain beliefs, and tricking us into coming up with logical rationalizations for false but survival-promoting beliefs. I am attracted to the UD+ASSA framework in part because it provides answers to these questions, answers which are in principle approximately computable and quantitative. Of course, it has assumptions of its own. But modelling a subjective lifespan as a computation, and asking how much measure the universe adds to that computation, seems to me to be a reasonable way to approach the problem. Even if it were possible to imagine another way of living my life which did not entail dying every moment, for example if certain significant components in my brain did not turn over, I would not expend any effort to bring this state of affairs about, because if it made no subjective or objective difference, what would be the point? Moreover, there would be no reason for evolution to favour this kind of neurophysiology unless it conferred some other advantage, such as greater metabolic efficiency. Right, so there are two questions here. One is whether there could be reasons to prefer a circumstance which seemingly makes no objective or subjective difference. I'll say more about this later, but for now I'll just note that it is often impossible to know whether some change would make a subjective difference. The other question is whether we could or should even try to overcome our evolutionary programming. If evolution doesn't care if we die once we have reproduced, should we? If evolution tells us to sacrifice ourselves to save two children, eight cousins, or 16 great-great uncles, should we? In the long run, we might be forced to obey the instincts built into us by genes. But it still is interesting to consider the deeper philosophical issues, and how we might hypothetically behave if we were free of evolutionary constraints. Hal Finney --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Teleportation thought experiment and UD+ASSA
Bruno raises a lot of good points, but I will just focus on a couple of them. The first notion that I am using in this analysis is the assumption that a first-person stream of consciousness exists as a Platonic object. My aim is then to estimate the measure of such objects. I don't know whether people find this plausible or not, so I won't try to defend it yet. The second part, which I know is more controversial, is that it is possible to represent this object as a bit string, or as some similar, concrete representation. I think there are a couple of challenges here. The first is how to turn something as amorphous and intangible as consciousness into a concrete representation. But I assume that subsequent development of cognitive sciences will eventually give us a good handle on this problem and allow us to diagram, graph and represent streams of consciousness in a meaningful way. As one direction to pursue, we know that brain activity creates consciousness, hence a sufficiently compressed representation of brain activity should be a reasonable starting point as a representation of first-person experience. Another issue that many people have objected to is the role of time. Consciousness, it is said, is a process, not a static structure such as might be represented by a bit string. IMO this can be dealt with by interpreting the bit string as a multidimensional object, and treating one of the dimensions as time. See, for example, one of Wolfram's 1-D cellular automaton outputs: http://en.wikipedia.org/wiki/Image:CA_rule30s.png We see something that can alternatively be interpreted as a pure bit string; as a two-dimensional array of bits; or as a one-dimensional bit string evolving in time. In the same way we can capture temporal evolution of consciousness by interpreting the bit string as having a time dimension. An important point is that although there may be many alternative ways and notations to represent consciousness, they should all be isomorphic, and only a relatively short program should be necessary to map from one to another. Hence, the measure computed for all of these representations will be about the same, and therefore it is meaningful to speak of this as the measure of the experience as a platonic entity. Bruno also questioned my use of a physical universe in my analysis. I am not assuming that physical universes exist as the basis of reality. I only expressed the analysis in that form because we were given a particular situation to analyze, and that situation was expressed as events in a single universe. The Universal Dovetailer does not play a principle role in my analysis, because it does not play such a role in Kolmogorov complexity. At most, the Universal Dovetailer can be used as a heuristic device to explain what it might mean to run all computatations in order to explain K complexity. I think one difference between K complexity and Bruno's reasoning with the Universal Dovetailer is that the former focuses on sizes of programs while Bruno seems to work more in terms of run time. In the K complexity view, the measure of an information object is (roughly) 1/2^L, where L is the size of the shortest program which outputs that object. Equivalently, the measure of an information object is the fraction of all programs which output that object, where programs are sampled uniformly from all bit strings (or from whatever the input alphabet is for the UTM). This does not have anything to do with run time. Some bit patterns may have short programs that take a very long run time to output them. Such bit patterns are considered to have low complexity and high measure, despite the long run time needed. I think Bruno has sometimes said that the Universal Dovetailer makes some things have higher measure than others because they get more run time. I'm not sure how this would work, but it is a difference from the Kolmogorov complexity (aka Universal Distribution) view that I am using. Okay, those are some of the foundational questions and assumptions that I think are raised by Bruno's analysis. The rest of it goes through as I have described many times. Hal --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Teleportation thought experiment and UD+ASSA
Russell Standish [EMAIL PROTECTED] writes: On Tue, Jun 20, 2006 at 09:35:12AM -0700, Hal Finney wrote: I think that one of the fundamental principles of your COMP hypothesis is the functionalist notion, that it does not matter what kind of system instantiates a computation. However I think this founders on the familiar paradoxes over what counts as an instantiation. In principle we can come up with a continuous range of devices which span the alternatives from non-instantiation to full instantiation of a given computation. Without some way to distinguish these, there is no meaning to the question of when a computation is instantiated; hence functionalism fails. I don't follow your argument here, but it sounds interesting. Could you expand on this more fully? My guess is that ultimately it will depend on an assumption like the ASSA. I am mostly referring to the philosophical literature on the problems of what counts as an instantiation, as well as responses considered here and elsewhere. One online paper is Chalmers' Does a Rock Implement Every Finite-State Automaton?, http://consc.net/papers/rock.html. Jacques Mallah (who seems to have disappeared from the net) discussed the issue on this list several years ago. Now, Chalmers (and Mallah) claimed to have a solution to decide when a physical system implements a calculation. But I don't think they work; at least, they admit gray areas. In fact, I think Mallah came up with the same basic idea I am advocating, that there is a degree of instantiation and it is based on the Kolmogorov complexity of a program that maps between physical states and corresponding computational states. For functionalism to work, though, it seems to me that you really need to be able to give a yes or no answer to whether something implements a given calculation. Fuzziness will not do, given that changing the system may kill a conscious being! It doesn't make sense to say that someone is sort of there, at least not in the conventional functionalist view. A fertile source of problems for functionalism involves the question of whether playbacks of passive recordings of brain states would be conscious. If not (as Chalmers and many others would say, since they lack the proper counterfactual behavior), this leads to a machine with a dial which controls the percentage of time its elements behave according to a passive playback versus behaving according to active computational rules. Now we can turn the knob and have the machine gradually move from unconsciousness to full consciousness, without changing its behavior in any way as we twiddle the knob. This invokes Chalmers' fading qualia paradox and is again fatal for functionalism. Maudlin's machines, which we have also mentioned on this list from time to time, further illustrate the problems in trying to draw a bright line between implementations and clever non-implementations of computations. In short I view functionalism as being fundamentally broken unless there is a much better solution to the implementation question than I am aware of. Therefore we cannot assume a priori that a brain implementation and a computational implementation of mental states will be inherently the same. And I have argued in fact that they could have different properties. Hal Finney --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Teleportation thought experiment and UD+ASSA
On Tue, Jun 20, 2006 at 11:11:15PM -0700, Hal Finney wrote: I am mostly referring to the philosophical literature on the problems of what counts as an instantiation, as well as responses considered here and elsewhere. One online paper is Chalmers' Does a Rock Implement Every Finite-State Automaton?, http://consc.net/papers/rock.html. Jacques Mallah (who seems to have disappeared from the net) discussed the issue on this list several years ago. Now, Chalmers (and Mallah) claimed to have a solution to decide when a physical system implements a calculation. But I don't think they work; at least, they admit gray areas. In fact, I think Mallah came up with the same basic idea I am advocating, that there is a degree of instantiation and it is based on the Kolmogorov complexity of a program that maps between physical states and corresponding computational states. For functionalism to work, though, it seems to me that you really need to be able to give a yes or no answer to whether something implements a given calculation. Fuzziness will not do, given that changing the system may kill a conscious being! It doesn't make sense to say that someone is sort of there, at least not in the conventional functionalist view. If computationalism is true, then a person is instantiated by all equivalent computations. If you change one instantiation to something inequivalent, then that instantiation no longer instantiates the person. The person continues to exist, as long as there remain valid computations somewhere in the universe. And in almost any of the many worlds variants we consider in this list, that will be true. A fertile source of problems for functionalism involves the question of whether playbacks of passive recordings of brain states would be conscious. If not (as Chalmers and many others would say, since they lack the proper counterfactual behavior), this leads to a machine with a dial which controls the percentage of time its elements behave according to a passive playback versus behaving according to active computational rules. Now we can turn the knob and have the machine gradually move from unconsciousness to full consciousness, without changing its behavior in any way as we twiddle the knob. This invokes Chalmers' fading qualia paradox and is again fatal for functionalism. It is only a problem in a single world ontology - in many worlds ontologies this is not a problem. Maudlin's machines, which we have also mentioned on this list from time to time, further illustrate the problems in trying to draw a bright line between implementations and clever non-implementations of computations. Indeed - it points to many worlds ontologies as necessary for functionalism to be true. This is, in fact, the point of Bruno's main argument. In short I view functionalism as being fundamentally broken unless there is a much better solution to the implementation question than I am aware of. Therefore we cannot assume a priori that a brain implementation and a computational implementation of mental states will be inherently the same. And I have argued in fact that they could have different properties. Hal Finney -- *PS: A number of people ask me about the attachment to my email, which is of type application/pgp-signature. Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Teleportation thought experiment and UD+ASSA
Saibal Mitra [EMAIL PROTECTED] writes: I don't understand why you consider the measures of the programs that do the simulations. The ''real'' measure should be derived from the algorithmic complexity of the laws of physics that describe how the computers/brains work. If you know for certain that a computation will be performed in this universe, then it doesn't matter how it is performed. I think what you're saying here is that if a mental state is instantiated by a given universe, the contribution to its measure should just be the measure of the universe that instantiates it. And that universe's measure is based on the complexity of its laws of physics. I used to hold this view, but I eventually abandoned it because of a number of problems. I need to go back and collect the old messages and discussions that we have had and put them into some kind of order. But I can mention a couple of issues. One problem is the one I just wrote about in my reply to Russell, the fuzziness of the concept of implementation. In at least some universes we may face a gray area in deciding whether a particular computation, or more specifically a particular mental state, is being instantiated. Philosophers like Hans Moravec apparently really believe that every system instantiates virtually every mental state! If you look at the right subset of the atomic vibrations inside a chunk of rock, you can come up with a pattern that is identical to the pattern of firing of neurons in your own brain. Now, most philosophers reject this, they come up with various technical criteria that implementations have to satisfy, but as I wrote to Russell I don't think any of these work. The other problem arises from fuzziness in what counts as a universe. The problem is that you can write very simple programs which will create your mental state. For example, the Universal Dovetailer does just that. But the UD program is much smaller than what our universe's physical laws probably would be. Does the measure of the UD count as a contribution to every mind it creates? If so, then it will dominate over the contributions from more conventional universes; and further, since the UD generates all minds, it means that all minds have equal measure. To reject the UD as a cheating non-universe means that we will need a bunch of ad hoc rules about what counts as a universe and what does not, which are fundamentally arbitrary and unconvincing. Then there are all those bothersome disputes which arise in this model, such as whether multiple instantiations should add more measure than just one; or whether a given brain in a small universe should get more measure than the same brain in a big universe (since it uses a higher proportion of the universe's resources in the first case). All these issues, as well as the ones above, are addressed and answered in my current framework, which is far simpler (the measure of a mental state is just its Kolmogorov measure - end of story). The algorithmic complexity of the program needed to simulate a brain refers to a ''personal universe''. You can think of the brain as a machine that is simulating a virtual world in which the qualia we experience exist. That world also exists independent of our brain in a universe of its own. This world has a very small measure defined by the very large algorithmic complexity of the program needed to specify the brain. I agree with this, I think. The program needed to specify a mental state a priori would be far larger than the program needed to specify the laws of physics which could cause that mental state to evolve naturally. Both programs make a contribution to the measure of the mental state, but the second one's contribution is enormously greater. The key point, due to Wei Dai, is that you can mathematically treat the two on an equal footing. As you have described it, we have a virtual world with qualia being created by a brain; and you have that same world existing independently as a universe of its own. Those are pretty different in a Schmidhuber type model. The second case is the output of one of the universe programs (a very very complex one). The first case is a rather intangible property of a universe program much like our own. To unify them we ask the question of how we can output a representation of that virtual world with qualia, using the shortest possible program. Assuming that there actually is a universe which naturally evolves a brain experiencing this mental state, we can do it with a two-part program: the first which creates and evolves the universe, and the second which analyzes the output of that universe to output the virtual world representation we seek. This second part basically translates the brain activity, part of the universe created by the first part, into whatever reprsentation we have chosen for the virtual world and qualia. Given that the universe created by the first part does evolve the brain states needed as input for
RE: Re: Teleportation thought experiment and UD+ASSA
Hal Finney writes: IshouldfirstmentionthatIdidnotanticipatetheconclusionthat IreachedwhenIdidthatanalysis.Ididnotexpecttoconcludethat teleportationlikethiswouldprobablynotwork(speakingfigurately). Thiswasnotthestartingpointoftheanalysis,buttheconclusion. Yes, but every theoretical scientist hopes ultimately to be vindicated by the experimentalists. I'm now not sure what you mean bythe second sentence in the above quote. What would you expect to find if (classical, destructive) teleportation of a subject in Brussels to Moscow and/or Washington were attempted? Stathis PapaioannouBe one of the first to try Windows Live Mail. Windows Live Mail. --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
RE: Re: Teleportation thought experiment and UD+ASSA
Stathis Papaioannou [EMAIL PROTECTED] writes: Hal Finney writes: I should first mention that I did not anticipate the conclusion that I reached when I did that analysis. I did not expect to conclude that teleportation like this would probably not work (speaking figurately). This was not the starting point of the analysis, but the conclusion. Yes, but every theoretical scientist hopes ultimately to be vindicated by the experimentalists. I'm now not sure what you mean by the second sentence in the above quote. What would you expect to find if (classical, destructive) teleportation of a subject in Brussels to Moscow and/or Washington were attempted? From the third party perspective, I'd expect that we'd start with a person in Brussels, and end up with people in Moscow and Washington who each have the memories and personality of the person who is no longer in Brussels. The population of Earth would have increased by one. I imagine that this is unproblematic and is simply a restatement of the stipulated conditions of the experiment. The more interesting question to ask is whether I would submit to this, and if so, what would I expect? Note that this is not subject to experimental verification. When we have described the third party situation, we have already said everything that experimentalists could verify. When those two people wake up in Moscow and Washington there is no conceivable experiment by which we can judge whether the person in Brussels has in some sense survived, or perhaps has done even better than surviving. It's not even clear what these questions mean. It was my attempt to formalize these questions which led to my analysis. Perhaps it is best if I go back to the more formal statement of the results, and say that the contribution of this universe to the measure of a person who experiences surviving the teleportation and wakes up in W or M is much less than the contribution to the measure of a person who walks into the machine in Brussels and never experiences anything else. At a minimum, this would make me hesitant to use the machine. Now, other philosophical considerations might still convince me to use the machine; but it would be more like the two copies are my heirs, people who will live on after I am gone and help to put my plans into action. People sometimes sacrifice themselves for their children, and the argument would be even stronger here since these are far more similar to me than biological relations. So even if I don't personally expect to survive the transition I might still decide to use the machine. Hal Finney --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Teleportation thought experiment and UD+ASSA
Russell Standish [EMAIL PROTECTED] writes: If computationalism is true, then a person is instantiated by all equivalent computations. If you change one instantiation to something inequivalent, then that instantiation no longer instantiates the person. The person continues to exist, as long as there remain valid computations somewhere in the universe. And in almost any of the many worlds variants we consider in this list, that will be true. That's true, but even with the MWI, making an instantiation cease to exist decreases the measure of that person. Around here we call that murder. The moral question still exists. I don't see the MWI as rescuing functionalism and computationalism. What, after all, do these principles mean? They say that the implementation substrate doesn't matter. You can implement a person using neurons or tinkertoys, it's all the same. But if there is no way in principle to tell whether a system implements a person, then this philosophy is meaningless since its basic assumption has no meaning. The MWI doesn't change that. Hal Finney --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Teleportation thought experiment and UD+ASSA
Hi Hal, Le Mercredi 21 Juin 2006 19:31, Hal Finney a écrit : What, after all, do these principles mean? They say that the implementation substrate doesn't matter. You can implement a person using neurons or tinkertoys, it's all the same. But if there is no way in principle to tell whether a system implements a person, then this philosophy is meaningless since its basic assumption has no meaning. The MWI doesn't change that. That's exactly the point of Bruno I think... What you've shown is that physicalism is not compatible with computationalism. In the UD vision, there is no real instantiation even the UD itself does not need to be instantiated, only the existence of the algorithm itself is necessary. Quentin --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Teleportation thought experiment and UD+ASSA
On Wed, Jun 21, 2006 at 10:31:16AM -0700, Hal Finney wrote: Russell Standish [EMAIL PROTECTED] writes: If computationalism is true, then a person is instantiated by all equivalent computations. If you change one instantiation to something inequivalent, then that instantiation no longer instantiates the person. The person continues to exist, as long as there remain valid computations somewhere in the universe. And in almost any of the many worlds variants we consider in this list, that will be true. That's true, but even with the MWI, making an instantiation cease to exist decreases the measure of that person. Around here we call that murder. The moral question still exists. I don't see the MWI as rescuing functionalism and computationalism. What, after all, do these principles mean? They say that the implementation substrate doesn't matter. You can implement a person using neurons or tinkertoys, it's all the same. But if there is no way in principle to tell whether a system implements a person, then this philosophy is meaningless since its basic assumption has no meaning. The MWI doesn't change that. Hal Finney There is no way to tell if a given system implements a person REGARDLESS of whether functionalism is true or not. The best we have is some kind of Turing test - if it walks and quacks like the only person we know (ourself), it is a person and if it doesn't then there is little benefit in assuming that it is a person. Cheers -- *PS: A number of people ask me about the attachment to my email, which is of type application/pgp-signature. Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
RE: Re: Teleportation thought experiment and UD+ASSA
Hal Finney writes: Yes,buteverytheoreticalscientisthopesultimatelytobevindicated bytheexperimentalists.I'mnownotsurewhatyoumeanbythesecond sentenceintheabovequote.Whatwouldyouexpecttofindif(classical, destructive)teleportationofasubjectinBrusselstoMoscowand/or Washingtonwereattempted? Fromthethirdpartyperspective,I'dexpectthatwe'dstartwitha personinBrussels,andendupwithpeopleinMoscowandWashingtonwho eachhavethememoriesandpersonalityofthepersonwhoisnolonger inBrussels.ThepopulationofEarthwouldhaveincreasedbyone. Iimaginethatthisisunproblematicandissimplyarestatementofthe stipulatedconditionsoftheexperiment. ThemoreinterestingquestiontoaskiswhetherIwouldsubmitto this,andifso,whatwouldIexpect?Notethatthisisnotsubject toexperimentalverification.Whenwehavedescribedthethirdparty situation,wehavealreadysaideverythingthatexperimentalistscould verify.WhenthosetwopeoplewakeupinMoscowandWashingtonthere isnoconceivableexperimentbywhichwecanjudgewhethertheperson inBrusselshasinsomesensesurvived,orperhapshasdoneevenbetter thansurviving.It'snotevenclearwhatthesequestionsmean. Itwasmyattempttoformalizethesequestionswhichledtomyanalysis. PerhapsitisbestifIgobacktothemoreformalstatementofthe results,andsaythatthecontributionofthisuniversetothemeasure ofapersonwhoexperiencessurvivingtheteleportationandwakesupin WorMismuchlessthanthecontributiontothemeasureofapersonwho walksintothemachineinBrusselsandneverexperiencesanythingelse. Ataminimum,thiswouldmakemehesitanttousethemachine. Now,otherphilosophicalconsiderationsmightstillconvincemetousethe machine;butitwouldbemorelikethetwocopiesaremyheirs,people whowillliveonafterIamgoneandhelptoputmyplansintoaction. Peoplesometimessacrificethemselvesfortheirchildren,andtheargument wouldbeevenstrongerheresincethesearefarmoresimilartomethan biologicalrelations.SoevenifIdon'tpersonallyexpecttosurvive thetransitionImightstilldecidetousethemachine. OK, I think I'm clear on what you're saying now. But suppose I argue that I will not survive the next hour, because the matter making up my synapses will have turned over in this time. To an outside observer the person taking my place would seem much the same, and if you ask him, he will share my memories and he will believe he is me. However, he won't be me, because I will by then be dead. Is this a valid analysis? My view is thatthere is a sense in which it*is* valid, but that it doesn't matter. What matters to me in survival is that there exist a person in an hour from now who by the usual objective and subjective criteria we use identifies as being me. Even if it were possible to imagine another way of living my life which did not entail dying every moment, for example if certain significant components in my brain did not turn over, I would not expend any effort to bring this state of affairs about, because if it made no subjective or objective difference, what would be the point? Moreover, there would be no reason for evolution to favour this kind of neurophysiology unless itconferred some other advantage, such as greater metabolic efficiency. Stathis PapaioannouWith MSN Spaces email straight to your blog. Upload jokes, photos and more. It's free! --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Teleportation thought experiment and UD+ASSA
Bruno writes: Hal, It seems to me that you are introducing a notion of physical universe,=20 and then use it to reintroduce a notion of first person death, so that=20 you can bet you will be the one annihilated in Brussels. I should first mention that I did not anticipate the conclusion that I reached when I did that analysis. I did not expect to conclude that teleportation like this would probably not work (speaking figurately). This was not the starting point of the analysis, but the conclusion. The starting point was the framework I have described previously, which can be stated very simply as that the measure of an information pattern comes from the universal distribution of Kolmogorov. I then applied this analysis to specific information patterns which represent subjective, first person lifetime experiences. I concluded that the truncated version which ends when the teleportation occurs would probably have higher measure than the ones which proceed through and beyond the teleportation. Although I worked in terms of a specific physical universe, that is a short-cut for simplicity of exposition. The general case is to simply ask for the K measure of each possible first-person subjective life experience - what is the shortest program that produces each one. I assume that the shortest program will in fact have two parts, one which creates a universe and the second which takes that universe as input and produces the first-person experience record as output. This leads to a Schmidhuber-like ensemble where we would consider all possible universes and estimate the contribution of each one to the measure of a particular first-person experience. It is important though to keep in mind that in practice the only universe which adds non-negligible measure would be the one we are discussing. In other words, consider the first person experience of being born, living your life, travelling to Brussels and stepping into a teleportation machine. A random, chaotic universe would add negligibly to the measure of this first-person life experience. Likewise for a universe which only evolves six-legged aliens on some other planet. So in practice it makes sense to restrict our attention to the (approximately) one universe which has third-person objective events that do add significant measure to the instantiation of these abstract first-person experiences. You agree that this is just equivalent of negating the comp hypothesis.=20 You would not use (classical) teleportation, nor accept a digital=20 artificial brain, all right? Do I miss something? It is perhaps best to say that I would not do these things *axiomatically*. Whether a particular teleportation technology would be acceptable would depend on considerations such as I described in my previous message. It's possible that the theoretical loss of measure for some teleportation technology would be small enough that I would do it. As far as using an artificial brain, again I would look to this kind of analysis. I have argued previously that a brain which is much smaller or faster than the biological one should have much smaller measure, so that would not be an appealing transformation. OTOH an artificial brain could be designed to have larger measure, such as by being physically larger or perhaps by having more accurate and complete memory storage. Then that would be appealing. I think that one of the fundamental principles of your COMP hypothesis is the functionalist notion, that it does not matter what kind of system instantiates a computation. However I think this founders on the familiar paradoxes over what counts as an instantiation. In principle we can come up with a continuous range of devices which span the alternatives from non-instantiation to full instantiation of a given computation. Without some way to distinguish these, there is no meaning to the question of when a computation is instantiated; hence functionalism fails. My approach (not original to me) is to recognize that there is a degree of instantiation, as I have described via the conditional Kolmogorov measure (i.e. given a physical system, how much does it help a minimal computation to produce the desired output). This then leads very naturally to the analysis I provided in my previous message, which attempted to estimate the conditional K measure for the hypothetical first-person computations that were being potentially instantiated by the given third-party physical situation. Hal Finney --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Teleportation thought experiment and UD+ASSA
On Tue, Jun 20, 2006 at 09:35:12AM -0700, Hal Finney wrote: The starting point was the framework I have described previously, which can be stated very simply as that the measure of an information pattern comes from the universal distribution of Kolmogorov. I then applied this analysis to specific information patterns which represent subjective, first person lifetime experiences. I concluded that the truncated version which ends when the teleportation occurs would probably have higher measure than the ones which proceed through and beyond the teleportation. Comment to Bruno - Hal starts with the ASSA. I'm pretty sure this negates functionalism and hence COMP. I just checked my book - I noted Hal as a staunch member of the ASSA camp :). This leads to a Schmidhuber-like ensemble where we would consider all possible universes and estimate the contribution of each one to the measure of a particular first-person experience. It is important Echoes of my previous correspondence to Bruno - it would seem Schmidhuber is an ASSA supporter too... I think that one of the fundamental principles of your COMP hypothesis is the functionalist notion, that it does not matter what kind of system instantiates a computation. However I think this founders on the familiar paradoxes over what counts as an instantiation. In principle we can come up with a continuous range of devices which span the alternatives from non-instantiation to full instantiation of a given computation. Without some way to distinguish these, there is no meaning to the question of when a computation is instantiated; hence functionalism fails. I don't follow your argument here, but it sounds interesting. Could you expand on this more fully? My guess is that ultimately it will depend on an assumption like the ASSA. -- *PS: A number of people ask me about the attachment to my email, which is of type application/pgp-signature. Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Teleportation thought experiment and UD+ASSA
I don't understand why you consider the measures of the programs that do the simulations. The ''real'' measure should be derived from the algorithmic complexity of the laws of physics that describe how the computers/brains work. If you know for certain that a computation will be performed in this universe, then it doesn't matter how it is performed. The algorithmic complexity of the program needed to simulate a brain refers to a ''personal universe''. You can think of the brain as a machine that is simulating a virtual world in which the qualia we experience exist. That world also exists independent of our brain in a universe of its own. This world has a very small measure defined by the very large algorithmic complexity of the program needed to specify the brain. Saibal From: Hal Finney [EMAIL PROTECTED] To: everything-list@googlegroups.com Sent: Tuesday, June 20, 2006 06:35 PM Subject: Re: Teleportation thought experiment and UD+ASSA Bruno writes: Hal, It seems to me that you are introducing a notion of physical universe,=20 and then use it to reintroduce a notion of first person death, so that=20 you can bet you will be the one annihilated in Brussels. I should first mention that I did not anticipate the conclusion that I reached when I did that analysis. I did not expect to conclude that teleportation like this would probably not work (speaking figurately). This was not the starting point of the analysis, but the conclusion. The starting point was the framework I have described previously, which can be stated very simply as that the measure of an information pattern comes from the universal distribution of Kolmogorov. I then applied this analysis to specific information patterns which represent subjective, first person lifetime experiences. I concluded that the truncated version which ends when the teleportation occurs would probably have higher measure than the ones which proceed through and beyond the teleportation. Although I worked in terms of a specific physical universe, that is a short-cut for simplicity of exposition. The general case is to simply ask for the K measure of each possible first-person subjective life experience - what is the shortest program that produces each one. I assume that the shortest program will in fact have two parts, one which creates a universe and the second which takes that universe as input and produces the first-person experience record as output. This leads to a Schmidhuber-like ensemble where we would consider all possible universes and estimate the contribution of each one to the measure of a particular first-person experience. It is important though to keep in mind that in practice the only universe which adds non-negligible measure would be the one we are discussing. In other words, consider the first person experience of being born, living your life, travelling to Brussels and stepping into a teleportation machine. A random, chaotic universe would add negligibly to the measure of this first-person life experience. Likewise for a universe which only evolves six-legged aliens on some other planet. So in practice it makes sense to restrict our attention to the (approximately) one universe which has third-person objective events that do add significant measure to the instantiation of these abstract first-person experiences. You agree that this is just equivalent of negating the comp hypothesis.=20 You would not use (classical) teleportation, nor accept a digital=20 artificial brain, all right? Do I miss something? It is perhaps best to say that I would not do these things *axiomatically*. Whether a particular teleportation technology would be acceptable would depend on considerations such as I described in my previous message. It's possible that the theoretical loss of measure for some teleportation technology would be small enough that I would do it. As far as using an artificial brain, again I would look to this kind of analysis. I have argued previously that a brain which is much smaller or faster than the biological one should have much smaller measure, so that would not be an appealing transformation. OTOH an artificial brain could be designed to have larger measure, such as by being physically larger or perhaps by having more accurate and complete memory storage. Then that would be appealing. I think that one of the fundamental principles of your COMP hypothesis is the functionalist notion, that it does not matter what kind of system instantiates a computation. However I think this founders on the familiar paradoxes over what counts as an instantiation. In principle we can come up with a continuous range of devices which span the alternatives from non-instantiation to full instantiation of a given computation. Without some way to distinguish these, there is no meaning to the question of when a computation is instantiated; hence functionalism fails. My
