1 All scientific theories permit creation of negative predictions: "It is impossible that ... will happen." If a theory cannot formulate negative predictions, then that theory is not science.

2 Yep.

3 So how does Naturalism explain scientific theories? That is, assuming Naturalism is correct, what is the explanation for the existence of beings who can formulate judgements such as "It is impossible that ... will happen", which are reliable?

4 So how does Naturalism explain scientific theories? It doesn't. Naturalism is a metaphysical framework (one of many) that is unique in that it makes Science possible. Naturalism, in itself, doesn't explain anything. That is, assuming Naturalism is correct, what is the explanation for the existence of beings who can formulate judgements such as "It is impossible that ... will happen", which are reliable? If you are asking Why do thinking creatures exist?, then the answer under Naturalism is Wrong question. Naturalism isn't about Why, it's about What and How.

5 I was mystified by Michael's question. Why should sapience be mysterious under a naturalist outlook? Then I realized that Michael has an a priori assumption of mind-body duality. Under a naturalist view of the universe, sapience is simply an emergent property of brain tissue. As such, there's no contradiction between a naturalist viewpoint and the existence of intelligences sufficiently sophisticated as to be able to ask these kinds of questions.

6 Something a lot of ID people don't realize is that the weak anthropic principle makes the unlikelihood of man's evolution a moot point. In order for intelligent life to be asking the question of how intelligent life occurred, intelligent life had to first occur. It's like showing up at a lottery winner's convention and being surprised by the fact everyone in the room won the lottery. Winning the lottery is improbable, but the improbable event was a requirement of being in the room.

7 Well, no, Mr. den Beste; I don't believe in mind-body duality as an a priori assumption. I believe it because no explanation of sapience as "an emergent property of brain tissue" covers the facts of sapience as we know them to be -- in particular, the fact that sapient beings can construct scientific theories, can judge that some types of events can never happen. Supposing Naturalism is true, whenever a sapient being makes a scientific judgement, the causes of that judgement must all be found in the material universe. (This holds because the judgement is an event in that universe.) The trouble is that a scientific judgement is also a statement about the universe, and has value only so far as it is true. And if a sapient being's judgements are solely the result of material causes, which is to say, of deterministic laws applied to random movements of particles -- then how can they also be the result of logical reasoning applied to evidence? If material causes fully account for judgements, their truth, being an immaterial cause, does not affect them; and therefore they are without value. And Pixy -- the question I asked wasn't Why sapience exists, but How it can exist, and What kind of thing it is. A Naturalist can't deny that those are valid questions, but can a Naturalist answer them? And I may as well start another hare: exactly what negative predictions are made by evolutionary theory? What sets of events does evolution say are impossible?

8 Supposing Naturalism is true, whenever a sapient being makes a scientific judgement, the causes of that judgement must all be found in the material universe. Naturalism says that all causes are Natural.. The trouble is that a scientific judgement is also a statement about the universe, and has value only so far as it is true. It has value in as much as it accurately represents the universe. And if a sapient being's judgements are solely the result of material causes, which is to say, of deterministic laws applied to random movements of particles -- then how can they also be the result of logical reasoning applied to evidence? When you say "deterministic laws applied to random movements of particles", you expose a deep confusion over the nature of the material universe. Certain quantum events are random; this much is true. The definition of random must be understood, though. We cannot predict, even in principle, when a single radioactive atom will decay. However, for a given isotope, the chance it will decay in any given time period is very precisely fixed. All random quantum events are like that; we can assign well-defined probabilities to all the possible movements or changes. Because of this, the statistical behaviour of matter on larger scales is extremely well defined. The brain appears to operate on that level, as do computers. Quantum randomness has little to do with the process. If material causes fully account for judgements, their truth, being an immaterial cause, does not affect them; and therefore they are without value. That doesn't make any sense at all. Truth is not a cause of any sort, material or immaterial. Truth is a desirable outcome; that's all. We make observations, we build hypotheses to explain those observations, and we test those hypotheses with further observations. And Pixy -- the question I asked wasn't Why sapience exists, but How it can exist That question is also meaningless. Try rephrasing it again. and What kind of thing it is. It's a material process. The evidence for this is quite direct from our observation of the matieral basis for thought (the brain). A Naturalist can't deny that those are valid questions, but can a Naturalist answer them? They aren't well-formed scientific questions, that much is certain. You don't seem to have the knack. And I may as well start another hare: exactly what negative predictions are made by evolutionary theory? What sets of events does evolution say are impossible? It says, to make a specific example, that you will not find hominid fossils in Silurian strata. While you will not always find all the transitional fossils to show how a given species evolved, there will be antecedents. It says that molecular and fossil evidence will support one another, with differences amounting to fine tuning. If you studied the genetic material of horses and could show that they were more closely related to water cress than to other mammals, that would falsify evolution. Evolution predicts that horses will be genetically to other mammals, and predicts that you won't find glaring counter-examples. And here's the point: We've made an IMMENSE number of observations and tests of this, and Evolution has passed every time. It's as well-tested as Relativity or Quantum Mechanics. None of these three theories explain everything, even within their own domains, but there is no question but that they are essentially sound.

9 what negative predictions are made by evolutionary theory? What sets of events does evolution say are impossible? It is impossible that a large number of species in the same ecosystem each have entirely different and unrelated mappings of RNA codon triples to amino acids. (In point of fact, every species ever studied uses exactly the same mapping.)

10 The tools of functional NMR and positron emittion tomography are rapidly expanding our knowledge of consciouness, memory, and "thought". If these are the central components of sapience, then we have at least a rudimentary understanding of them now, and can expect that knowledge to increase exponentially in the years to come. The mechanism by which an organic brain stores information is one of the coolest things I can think of, no pun intended.

11 Why did my comment just now end up in the "hold for approval" queue?

12 And Pixy -- the question I asked wasn't Why sapience exists, but How it can exist That question is also meaningless. Try rephrasing it again. This reminds me of a quote that was the foreword in a Stross book. "To me, asking the question of whether a computer can think is no more interesting than asking whether a submarine can swim." A thermostat exhibits the most basic tenet of sapience response to stimuli. Sapience is no great trick, really, just a very very complicated interrelationship of billions of little thermostats responding to billions of stimuli every microsecond.

13 Steven - It's a "feature" of Movable Type 3.1. I haven't been able to work out what critera it uses, but it does it to me as well.

14 The tools of functional NMR and positron emittion tomography are rapidly expanding our knowledge of consciouness, memory, and "thought". This is true, but the material origin of thought can be demonstrated with much simpler tools... Like, say, a baseball bat.

15

Pixy: The details of how quantum mechanics generates quasi-deterministic results aren't germane to my argument; the key question is, "if a sapient being's judgements are solely the result of material causes ... then how can they also be the result of logical reasoning applied to evidence?" The comparison of humans to computers may illustrate the point. The execution of a computer program is the result of material causes (electrical power, the design of the circuits, the state of the memory devices) and is fully explained by them. And this means the computer's final state is absolutely determined by its initial state -- it cannot calculate any result except the one implied by the information given it. It cannot, in particular, recognize that the algorithm guiding the course of the execution is unsound. There's no gap left over in which logical reasoning from evidence could possibly influence the execution's result. (Nor, in a computer, would you want any such gap to exist!)

Now, under the assumption that human brains are only computers, we would have to admit that human judgements are results of some program's execution, from which it follows that such judgements are wholly determined by some initial state -- present perceptions, memories of past perceptions, etc. And it equally follows that logical reasoning has no influence over human judgements; and if the algorithm which gives rise to judgements is unsound, the human making a judgement could never discover it. Are you prepared to accept those propositions?

Passing to another point: would you agree that the question "how can carbon nuclei be generated within stars in great numbers" is meaningless? For if you did, you would have dismissed Fred Hoyle's speculation (later confirmed) that the carbon nucleus has a specific energy level.

I have always supposed that questions of the form "here is ...; how can it exist?" are exactly those that science is best equipped to answer.

Neal: don't jump too soon to the conclusion that the neuroscientists are looking at all the components of sapience. I recommend to you the work of David Chalmers on consciousness.

16 It cannot, in particular, recognize that the algorithm guiding the course of the execution is unsound. Computers are perfectly capable of examining their own programming, or of applying more than one method to the input data and comparing the results. So your statement is utterly false, and any conclusions you might draw from it are baseless. A given program may or may not be able to determine its own reliability, but if it gets wrong answers, and attempts to apply those answers in the real world, it will fail (one way or another). The same, of course, applies to brains. Passing to another point: would you agree that the question "how can carbon nuclei be generated within stars in great numbers" is meaningless? It's not a well-formed scientific question. Ask rather How are carbon nuclei formed within stars? Or more simply, How are carbon nuclei formed? I have always supposed that questions of the form "here is ...; how can it exist?" are exactly those that science is best equipped to answer. No. "How can it exist?" as framed is a question of metaphysics. "Where did it come from?" is a scientific question. I recommend to you the work of David Chalmers on consciousness. David Chalmers is a fruit bat. His work on consciousness is worse than useless. In particular, his "hard-problem consciousness" is complete drivel. "Why", he asks, "is the system that performs these functions conscious?" Wrong question. Chalmers: "Perhaps accounts of this kind can tell us about the neurophysiological or information-processing *correlates* of conscious experience. This is useful, but the correlation itself remains unexplained: why does the physical process give rise to experience at all? These are simply the wrong *type* of methods to answer this question." That's because you're asking an unscientific question and looking at scientific answers. Dumbass. Once again: Computer programs are quite commonly introspective, to various degrees, examining aspects of their own internal models and adjusting themselves accordingly. They do this because it is useful. I'd suggest reading Daniel Dennett. He's far from perfect, but at least his work has some basis in reality.

17 In fact, this is particularly apropos, because Chalmers is to neuroscience what Intelligent Design is to evolutionary theory. The arguments are identical: "You can't explain this to my satisfaction, therefor magic fairies did it." However, the IDists at least point out real gaps in the fossil record; Chalmers merely highlights the flaws of his own assumptions.

18 So (finally), to answer Chalmer's question: Why is the system that performs these functions conscious? Utility.

19 Computers are perfectly capable of examining their own programming, or of applying more than one method to the input data and comparing the results.

This is true only for programs on the "application" level. I was thinking more of circuitry errors like the Intel Pentium's division error, or security holes in an OS's kernel. Errors on that level aren't things a computer can fix by itself.

And you haven't given an answer to this bit: "under the assumption that human brains are only computers, we would have to admit that human judgements are results of some program's execution, from which it follows that such judgements are wholly determined by some initial state ... it equally follows that logical reasoning has no influence over human judgements". Is there really nothing in that which strikes you as objectionable?

20 This is true only for programs on the "application" level. I was thinking more of circuitry errors like the Intel Pentium's division error, or security holes in an OS's kernel. Errors on that level aren't things a computer can fix by itself. Yes they are. The OS kernel is just another application. Hardware is trickier, but that's akin to brain surgery rather than self-awareness, so the point is moot. "under the assumption that human brains are only computers, we would have to admit that human judgements are results of some program's execution, from which it follows that such judgements are wholly determined by some initial state ... it equally follows that logical reasoning has no influence over human judgements" No. There are three factors: The initial state. The process. The data being input. The process is the logic, and it is only one of the parts. Of course, you can't reset a brain the way you can a regular computer, so the initial state is not well defined. I'll ignore that for now, because you're wrong anyway. What's more, brains don't run programs, and don't necessarily use algorithms. (Algorithms are only one model of computing, and are not the one brains are most suited to.) Is there really nothing in that which strikes you as objectionable? Sure. It's completely wrong in every way.

21 I don't suppose that it's worth pointing out that the human brain is not isomorphic to a Turing Machine? In other words, it is not a "computer", in the technical sense of the term. It cannot be simulated by a Turing Machine, and mathematical proofs of uncomputability based on isomorphism to the "stopping problem" don't apply to the human brain. There are several reasons why neural systems are not "computers": neural systems are asynchronous, neural systems are fundamentally analog, and neural systems are not 100% deterministic in execution. (Also, behavior of neural systems is influenced not only by signal inputs, but also by such factors as fatigue, nutrition, genetics, blood hormone levels, and what other information has been processed recently -- and is being processed simultaneously, since neural systems never work on only one problem at a time.) Thus any attempt to map concepts from computer science to neuroscience is fraught with conceptual pitfalls, because those concepts may apply only partially, and may not apply at all. ...under the assumption that human brains are only computers, we would have to admit that human judgements are results of some program's execution, from which it follows that such judgements are wholly determined by some initial state -- present perceptions, memories of past perceptions, etc. Since human brains are not computers, this entire argument is irrelevant.

22 Well, Turing Machines are physically impossible, so the fact that the brain isn't one is not much of a surprise. Computer science can provide insights into how certain things might be possible, and computer science does study neural networks as well as conventional algorithmic systems. Whether human brains are computers depends on your definition of "computer", but we can infer from Michael's statements that under his definition, they aren't.

23 I had intended the comparison between computers and brains as an illustration, not as the core of the argument, and once again what I regard as the core has been missed. Entirely my fault, of course. Let me see if I can phrase it properly this time. I'll start from this remark:

There are several reasons why neural systems are not "computers": neural systems are asynchronous, neural systems are fundamentally analog, and neural systems are not 100% deterministic in execution. (Also, behavior of neural systems is influenced not only by signal inputs, but also by such factors as fatigue, nutrition, genetics, blood hormone levels, and what other information has been processed recently -- and is being processed simultaneously, since neural systems never work on only one problem at a time.)

All of these outside influences, as well as the neural connections and signals, are material things; in principle, if we had a complete and detailed description of the brain at a specified time, and all the outside influences on the brain starting at that time, we could give an equally complete and detailed description of the brain at any future time. (Or, if quantum effects are relevant, we could give an ensemble of possible descriptions. I doubt this makes a difference to the argument.)

At some level of abstraction, there are events in any human brain which we call judgements; and these are supposed to be the conclusions, by a logical process of reasoning, from collections of evidence. Now, under the assumption of Naturalism judgements, like all other events, are only the results of material causes -- indeed, they are wholly composed of, and reducible to, events listed in one of the complete and detailed descriptions of the brain in which they occur. And the problem is, if this is the case, it does not seem possible for judgements to be, in addition, conclusions of an argument.

The form of a judgement is fully explained by the material events which are its constituents and the causes of those events, and logical reasoning is not one of those causes. Decompose a judgement down to the states of elementary particles; you will not find arguments or inferences. Trace back the changes of state that gave rise to the judgement; again you will not find arguments or inferences. And Naturalism admits no other kind of cause. So how is a judgement supposed to represent any aspect of reality, except itself? How does a judgement, under Naturalism, manage to be true, or false; or have any meaning at all?

In a word: is there a consistent epistemology of Naturalism?

24 I had intended the comparison between computers and brains as an illustration, not as the core of the argument Sure, and I took it as such, and you're still wrong. The differences between brains and computers are important to remember, but they aren't the key to the fallacy of your argument. if quantum effects are relevant, we could give an ensemble of possible descriptions Quantum effects are inescapable, but we don't know to what degree they are significant here. Chaos theory is also relevant, however, and the result is that what you are suggesting is quite impossible. Sorry. At some level of abstraction, there are events in any human brain which we call judgements; and these are supposed to be the conclusions, by a logical process of reasoning, from collections of evidence. Correct. Now, under the assumption of Naturalism judgements, like all other events, are only the results of material causes Correct. -- indeed, they are wholly composed of, and reducible to, events listed in one of the complete and detailed descriptions of the brain in which they occur. Which sadly cannot exist, but again, this is not the key to the problem. And the problem is, if this is the case, it does not seem possible for judgements to be, in addition, conclusions of an argument. Nonsense. The brain applies transformations (limited by the laws of physics) to its sensory input and its memories. The output of this process includes judgements of the nature of the sensory data it has received. There is no difficulty here. The form of a judgement is fully explained by the material events which are its constituents and the causes of those events, and logical reasoning is not one of those causes. Logical reasoning is the process. It doesn't need to be a cause. You're looking at the wrong level of abstraction. You're seeing lots of dots, but no picture. Decompose a judgement down to the states of elementary particles; you will not find arguments or inferences. Yes. That's because you've decomposed it. Decompose an apple down to its component molecules and you don't have an apple any more. This is the Logical Fallacy of Division. Trace back the changes of state that gave rise to the judgement; again you will not find arguments or inferences. Yes you will. You just have to examine it at the right level of abstraction. And the mind has many levels of abstraction. So of course do computers. Arguments and inferences do not have any existence of themselves; they have to be represented. Computers and brains form representations of these (and other concepts) and manipulate them. They do this in different ways, but they perform the same fundamental task. How does a judgement, under Naturalism, manage to be true, or false; or have any meaning at all? Insofar as it is a valid statement about reality. Which can be judged by testing it against reality. In a word: is there a consistent epistemology of Naturalism? In a word: Yes.

25 All of these outside influences, as well as the neural connections and signals, are material things; in principle, if we had a complete and detailed description of the brain at a specified time, and all the outside influences on the brain starting at that time, we could give an equally complete and detailed description of the brain at any future time. (Or, if quantum effects are relevant, we could give an ensemble of possible descriptions. I doubt this makes a difference to the argument.) To which Pixy responds: Chaos theory is also relevant, however, and the result is that what you are suggesting is quite impossible. Quite so, and the reason is the Butterfly Effect: initial errors in specifying the state of the system, no matter how small, cascade and accumulate in the predictive process, and beyond a certain time horizon lead the prediction to bear essentially no resemblance to the real system, rendering the prediction completely useless. The Butterfly Effect is a profound result of Chaos Theory. In this case what it means is that the "ensemble of possible descriptions" must necessarily include the entire possible outcome space -- which is to say, it won't actually permit a prediction because it can't exclude anything.

26 Michael, the fundamental flaw of your argument is that you implicitly deny the existence of emergent properties. Stripped to its core, your argument is the following: 1. Atoms cannot think. 2. Brains composed of atoms therefore cannot think. 3. We know that thought exists. 4. Therefore thought must take place in some way which is not a reflection of the physical matter of the brain. 5. Thus the mind is not the same as the brain, and we have proved essentialism and mind-body duality. The problem with your argument is step 2, because it requires that the brain not exhibit any properties that cannot be demonstrated in its component parts (ultimate, the atoms that make it up). And the reason that step 2 is invalid is because of emergent properties. They're an observable fact; emergent properties do exist. Systems engineers (like me) deal with them all the time; in a sense "systems engineering" is precisely the study of emergent properties, because the only reasonable definition of "system" I've ever come up with is "a collection of components which, when interacting, demonstrate emergent properties". The following argument is invalid: "None of the components of the system have thus-and-so property, therefore the system itself cannot have thus-and-so property." That isn't a valid inference; the system may well have emergent properties which are not characteristics of any of the components. (And you cannot necessarily learn anything about the emergent properties of a system through detailed examination of the components. That's pretty close to the first practical lesson that systems engineers learn.) That's where your argument fails: At some level of abstraction, there are events in any human brain which we call judgements; and these are supposed to be the conclusions, by a logical process of reasoning, from collections of evidence. Now, under the assumption of Naturalism judgements, like all other events, are only the results of material causes -- indeed, they are wholly composed of, and reducible to, events listed in one of the complete and detailed descriptions of the brain in which they occur. And the problem is, if this is the case, it does not seem possible for judgements to be, in addition, conclusions of an argument. "wholly composed of" DOES NOT IMPLY "reducible to". The properties of the system are not necessarily all present in the components. Thus to argue about whether those properties are present in the components is irrelevant to whether those properties are present in the system. And that's why your entire argument collapses.

27 Um, I hate to inject in the middle of this learned discourse, but why are Turing machines impossible? And why is a complete and detailed description of the working state of a brain impossible? [Certainly, it's impossible with our current level of technology].

28 The Turing Machine is a mathematical concept, not a practical one. It requires an infinitely long tape, and it must be perfectly reliable. Very useful for testing out ideas of what is and isn't computable, but not something you'd try to build. It may be possible to come up with a "good enough" description of the working state of the brain; I think this is likely. What Michael was suggesting is that we could then use that to predict future brain states; we can't, because the brain is (a) too complicated and (b) too sensitive to variations in the initial state. That's where Chaos Theory (the Butterfly Effect) comes into it.

29 owlish, Alan Turing himself questioned Turing computability. perhaps michael needs an oracle machine. http://en.wikipedia.org/wiki/Oracle_machine

I personally like Sir Roger's take. Penrose proposes that the physiological process underlying a given thought may initially involve a number of superposed quantum states, each of which performs a calculation of sorts. When the differences in the distribution of mass and energy between the states reach a gravitationally significant level, the states collapse into a single state, causing measurable and possibly nonlocal changes in the neural structure of the brain. This physical event correlates with a mental one: the comprehension of a mathematical theorem, say, or the decision not to tip a waiter.

30 Personally I loathe Penrose's take. It's the same argument, again, as Intelligent Design and Chalmers' "Hard Problem Consciousness", though at least Penrose names his magic fairies. There is no physical evidence that what Penrose is suggesting is even possible, and certainly no reason to suspect that it is necessary.

31 Personally, I believe in magic fairies. ;)

32 Well, yes, but not inside my brain. :p

33 Turing computability is a very powerful mathematical tool, but its limits have to be understood. The fact that a given calculation cannot be completed by a Turing machine in finite time doesn't imply that it cannot be computed by anything at all. The classic demonstration of that is calculating the square root of 2. Since the square root of 2 is an irrational number, an exact calculation of it would require an infinite number of bits, and therefore would require an infinite amount of time to calculate. But an ideal straight edge and compass can "calculate" the square root of 2 in a relatively small number of steps. Given two marks on a line which define a line segment of length "1", then draw a perpendicular line through one of those two marks and place a mark "1" away from the original line on the new line. Then draw the diagonal. The length of the diagonal has a length equal to the square root of 2. (Note that this applies to an ideal compass and an ideal straight edge, which means that the line is infinitely narrow, and measurements are perfectly reproducible, etc.) The reason is that calculations performed with a straight edge and a compass are not isomorphic to a Turing Machine, and thus are not bound by the limits of a Turing Machine.

34 oh, pixy, Sir Roger does not even call his objective orchestrated reduction model a theory, yet. how can you equivalence quantum consciousness with ID? what if tomorrow we discover Higgs bosuns at the large haldron super collidor? There is a vast difference between quantum consciousness and ID--and it is called mathematics. and susie, i also believe in magic fairies. ;-)

35 how can you equivalence quantum consciousness with ID? The same principle applies: "You can't explain this to my satisfaction, therefor magic fairies did it." Penrose's magic fairies are some sort of quantum gravity effects; as I said, there is no reason to think that anything of the sort plays any part in brain function; nor is anything of the sort required to explain brain function. Higgs bosons make no difference one way or the other. There is a vast difference between quantum consciousness and ID--and it is called mathematics. IDists use mathematics to "prove" their points too. But they, like Penrose, are using numbers that have no bearing on the problem.

36 Pixy, Higgs bosons (if they exist) are a step in proving Penrose's magic fairies.

IDist's do not use use mathematics, in the sense that i understand mathematics. the complexity argument is bogus as applied to ID. and, ID has already lost the memetic war against evolution, if you look at public opinion. we should go on to more interesting arguments.

the real difference between quantum theorists and IDist's, is that ID is desperately trying to cling to something from our past, and quantum theorists are thinking about something in our future. Penrose et al are the new heretics, metaphysicists like Newton and Leibnitz were in their time. they may, indeed, be wrong. but at least they are not afraid to think outside the box.

37 Pixy, your flame wars are much too civilized.

38 Got it. Thanks. And obviously, the magic faeries work for His Noodly Greatness, giving meatballs to good little children and destroying bad little children with quantum singularities. :)

39 Pixy, Higgs bosons (if they exist) are a step in proving Penrose's magic fairies. No they're not. The Higgs bosons (if the exist) help us understand why matter has mass. Penrose's ideas on consciousness are bollocks. Higgs bosons or no, his idea has no merit, and it's still "magic fairy" thinking. And it's counter to several thousand years of collected evidence that consciousness is a product of biochemistry. There's no evidence that what Penrose suggests is posible; there's no evidence to suggest that it is necessary; and there's a billion tons of evidence to suggest that it's utter nonsense. The magic fairies may be couched in terms of theoretical physics, but magic fairies is what they are.

40 oh! thanx wonderduck-- i almost forgot to comment on the anime thread! pixy, i am going to go gather escalation material--this flame war is heating up. ;-)

41 No problem. I've argued these points before on various web forums (JREF and Internet Infidels, for example). The problem there was that the people I was arguing with were complete idiots. This isn't the case here. I disagree with you and Michael, but you are both able to put forward a coherent argument. (In one previous discussion I had an opponent claim that logic had no place in debate. Seriously.)

42 but pixy, are we really arguing? isn't the bio-electro-chemical aggregate we know as personality or soul formed of some underlying elements, like say.....matter and energy? ;-)

43 isn't the bio-electro-chemical aggregate we know as personality or soul formed of some underlying elements, like say.....matter and energy? Sure. But that's not what Penrose is saying.

44 hmmm...i thought Penrose was saying we need something extra to understand the non-computability of conscious thought....what do you think he is saying? perhaps i should call for backup....but there is always the problem that my backup may take pixy's side. ;-)

45 pixy, what do you think of this? http://www.techcentralstation.com/081005A.html

46 i thought Penrose was saying we need something extra to understand the non-computability of conscious thought Yes. And there is no reason to believe this is the case, and there is no reason to believe that his alternative explanation is possible at all. He's a good mathematical physicist, but he knows absolutely nothing about brain function.

47 What I think of that article is this: As soon as you step into theology, you can forget about anything making sense. Theology doesn't. It's just an attempt to rationalise the irrational. I do like the term deus absconditus though.

48 I've just enabled TypeKey logins. I don't like TypeKey much, but it's better than having to manually approve every comment on a thread like this.

49 testing........

50 I think it worked!

51 Pixy, then you believe all thought is Turing computable? I thought Den Beste-sama just proved it is not.

Doesn't there have to be an interface between biology and mathematics somewhere? Is that interface physics?

I like Max Tegmark quite a lot too. "In other words, our successful theories are not mathematics approximating physics, but mathematics approximating mathematics."

52 Actually, what Steven pointed out is that it's irrelevant whether thought is Turing computable or not (for this purpose) because the brain is not a Turing machine. I haven't read Tegmark, but I'll look him up.

53 You step away from a discussion for a few days, and look at what happens...

About Penrose. We need to distinguish between his various speculations. His ideas on objective state reduction as part of a theory of quantum gravity come from attempts to integrate quantum mechanics and general relativity, theories which (though confirmed separately by hosts of evidence) are not compatible as they stand. The quantum gravity hypotheses, that is, are answers to a question posed within physics.

Penrose's argument against "strong AI" comes out of the foundations of mathematics and the theory of computation; it exploits, that is, the results of Goedel, Turing, Church, and Tarski. And the speculations on consciousness depend on that argument and the quantum gravity hypotheses, plus some interesting experimental data.

... it's counter to several thousand years of collected evidence that consciousness is a product of biochemistry.

There's several thousand years of evidence that biochemistry is necessary to human consciousness. Not a shred of it is evidence that biochemistry suffices, which is the question at hand.

Michael, the fundamental flaw of your argument is that you implicitly deny the existence of emergent properties.

Actually, no, I don't deny the existence of emergent properties; what I deny is that the completion of a judgement can be an emergent property of matter. Unfortunately I haven't time just now to state my reasons properly, but as a hint: if the components of a system all have a property X, and all the available ways to combine components preserve X, then the system as a whole must have X. That rule of inference is called "structural induction".

54 There's several thousand years of evidence that biochemistry is necessary to human consciousness. Not a shred of it is evidence that biochemistry suffices, which is the question at hand. We haven't shown that biochemistry suffices; this is true. To do that we need an operational theory of consicousness, something we don't have. What it does show is that all competing theories are bunk, and that biochemistry is entirely plausible. The evidence comes not only from the fact that chemicals in the bloodstream can directly and predictably effect consciousness, but from the way they do so. Consciousness acts in all ways as though it were being produced by the biochemistry and electrochemistry of the brain. We can't explain exactly how, but that's no reason to introduce magic fairies. Unfortunately I haven't time just now to state my reasons properly We'll wait. if the components of a system all have a property X, and all the available ways to combine components preserve X, then the system as a whole must have X. That rule of inference is called "structural induction". Which is nice, but in no way addresses the point. Emergent properties are ones where the system has property X, but the components do not. Emergent properties are real, and you have shown not a shred of evidence that judgement cannot be one of them. And we can show that things that outwardly look remarkably like judgement can be produced as emergent properties of computer programs. So why not the brain?

55 Hello, I'm back again!

As I said before, I don't deny that emergent properties exist; in fact I can supply an example which the article I just linked to missed -- natural languages emerge, in exactly this sense, from human communities. But let us analyze the examples of emergence more closely.

The pressure and temperature of a gas emerge from the energy and momentum of the gas' constituent molecules; but pressure and temperature are defined in terms of the energy and momentum of the gas as a whole. Market prices regulate the use of goods and services in an economy, without need for a single director; but those prices, which summarize recent transactions, emerge by means of a host of attempted transactions. Languages, which regulate communications among the members of a community, normally emerge from and by means of people's attempts to communicate with each other.

The common thread is, I trust, clear: in each case the macro-scale emergent structure is of the same category as the micro-scale events from which it emerges. And this holds for every emergent property. So, if judgements are to be emergent properties, we must find some micro-scale events, of the same category as judgements but less structured, out of which a judgement could emerge.

Now there is a plausible candidate for this in perception -- which I define as recognition, by a sapient being, that some other event not only has occurred, but has significance. The trouble is that Naturalism denies any significance to the idea of significance. The suggestion that an event means, as well as occurs, is metaphysical, beyond the limits of science, therefore (to the Naturalist) without explanatory power. So Naturalists cannot appeal to perception as the ground of judgements.

To restate: the problem for the Naturalist is not to explain how the orderly structure of a scientific judgement emerges from a chaos, but to characterize the chaos from which a judgement emerges, without admitting the existence of immaterial entities.

And we can show that things that outwardly look remarkably like judgement can be produced as emergent properties of computer programs.

To the best of my knowledge, the two types of programs which come closest to performing judgements are heuristic-guided search and data mining. Neither of these really resembles the method of reasoning that scientists actually employ; and more importantly, the part of human reasoning they do resemble is the "emergent" aspect, bringing chaos into order, which is not where the difficulty lies.

56 Welcome back! You might want to drop in on the God's Gift to Neuroscience thread, where we are discussing beer and Penrose's speculations on the origins of consciousness in quantum gravity fluctuations. (I think Penrose is nuts wrong.) Anyhow: So, if judgements are to be emergent properties, we must find some micro-scale events, of the same category as judgements but less structured, out of which a judgement could emerge. Easily done. Judgements are information processing. All interactions involve the processing of information. That's your category right there. The trouble is that Naturalism denies any significance to the idea of significance. This is true (if you define your terms carefully), but in exactly the same way, Naturalism denies any significance to the idea of judgement. So your argument fails; insignificant perception can perfectly well give rise to insignifcant judgement. To restate: the problem for the Naturalist is not to explain how the orderly structure of a scientific judgement emerges from a chaos, but to characterize the chaos from which a judgement emerges, without admitting the existence of immaterial entities. There simply isn't a problem. You think there is a problem because you are importing a concept of judgement that simply doesn't apply under Naturalism. This sort of thing is universal among philosophers who try to find fault with Naturalism, so there's no need to be embarassed. Many thousands of pages of argument have been published with the same central flaw. Neither of these really resembles the method of reasoning that scientists actually employ; and more importantly, the part of human reasoning they do resemble is the "emergent" aspect, bringing chaos into order, which is not where the difficulty lies. There is no difficulty. The output of such a computer program can look exactly like a human judgement, given an appropriate program and class of problem. (That's based on real, working programs available today, not on information-processing theoreticals.) If you can't distinguish between machine generated "judgement" and human Judgement, you simply have no basis on which to argue that they are not equivalent. The only thing you are left with is a "Judgement of the Gaps" argument: That Significant Judgement is whatever has not already been demonstrated to be Turing-computable. Trust me, you don't want to go there.

57 The common thread is, I trust, clear: in each case the macro-scale emergent structure is of the same category as the micro-scale events from which it emerges. And this holds for every emergent property. I'm afraid not. Take, for example, oscillation. Some systems oscillate, but there's no characteristic of the components which has anything to do with oscillation. Oscillation is an emergent property of the system which corresponds to no "microscale event". One NOT-gate doesn't inherently oscillate. Two NOT-gates wired input-to-output oscillate like crazy. Market prices regulate the use of goods and services in an economy, without need for a single director; but those prices, which summarize recent transactions, emerge by means of a host of attempted transactions. If two people engage in a transaction, that is a system and the transaction is an emergent property of that system. All you've proved is that sometimes the emergent properties of large systems are imperfectly reflected in the emergent properties of small systems. One person is not a system (at least for purposes of this particular discussion, because one person cannot engage in meaningful transactions). What is the "microscale event" in a single person which corresponds to market pricing? There is none.

58 ok pixy, you have proven that biochemistry is neccessary, but you have not proven that it is sufficient. can you do that proof?

59

Judgements are information processing. All interactions involve the processing of information. That's your category right there.

This would be satisfactory, if you had defined "information" as a result of material causes. However, as far as I am aware "information" belongs to the same family as "significance", "meaning", and "purpose". Which is to say, information is exactly what Naturalism excludes from the set of admissible causes of events: a non-material phenomenon. By making information processing a universal law, you have in effect declared that elementary particles think, and endorsed the ideas of Chalmers and Penrose.

You think there is a problem because you are importing a concept of judgement that simply doesn't apply under Naturalism.

Why yes, I am. Except that it's not a "concept" of judgement I'm appealing to; it's the thing itself, the experience of reaching a judgment, which every human being shares to some extent, of which the scientific method is a refinement. Saying that judgement as we experience it "doesn't apply under Naturalism" is just like saying the orbit of Mercury isn't what astronomers observe it to be, because Newton's theory of gravity would put it somewhere else.

60

Some systems oscillate, but there's no characteristic of the components which has anything to do with oscillation. Oscillation is an emergent property of the system which corresponds to no "microscale event".

Ah ... oscillation of what? You mention logic gates -- there, what oscillates is the voltage passing through the wires that connect the gates, correct? And voltage in a wire is certainly a characteristic of a component of the logic circuit (the circuit being the whole system.)

If two people engage in a transaction, that is a system and the transaction is an emergent property of that system ... One person is not a system ... What is the "microscale event" in a single person which corresponds to market pricing?

OK, now we're getting serious.

If we're going to analyze transactions as systems, the question is what, exactly, their components are. Obviously, these are the things to be exchanged, and the intentions of the exchangers. It is also obvious that exchangable things can exist, and that agents can have intentions, outside of transactions. So the "atoms" of markets are, goods and services, and the intentions of agents. But can you maintain that the prices of goods and services belong to a different category from an agent's intentions? Such was not my understanding of the economics textbooks I have read.

61 This would be satisfactory, if you had defined "information" as a result of material causes. I do. Because it is. However, as far as I am aware "information" belongs to the same family as "significance", "meaning", and "purpose". Not at all. Information has a specific definition in physics (closely related to entropy), and of course in computer science and information science. Information in computer science and cognitive science is closely tied to the idea of representation and instantiation. Concepts (judgement, for example) cannot exist by themselves; they must be instantiated in the properties and processes of a physical system. Which is to say, information is exactly what Naturalism excludes from the set of admissible causes of events: a non-material phenomenon. Not at all. Information is necessarily a material phenomenon. By making information processing a universal law, you have in effect declared that elementary particles think, and endorsed the ideas of Chalmers and Penrose. No. There is a world of differences between informational transactions and thinking. Unless you consider that, for example, diodes think. Except that it's not a "concept" of judgement I'm appealing to; it's the thing itself, the experience of reaching a judgment, which every human being shares to some extent, of which the scientific method is a refinement. Judgement is information processing. Exactly the same sort of information processing as you can perform with transistors or relays or clever arrangements of cogs and cams. Saying that judgement as we experience it "doesn't apply under Naturalism" is just like saying the orbit of Mercury isn't what astronomers observe it to be, because Newton's theory of gravity would put it somewhere else. I didn't say that. I simply pointed out that there is no special significance to judgement; it is merely a result of material processes. These material process acts entirely according to the laws of physics, and we choose to label one of the results as "judgement". And that's all there is. It's more akin to pointing out that just because there is a planet named Mercury doesn't mean that it is the messenger of the gods.

62 Ah ... oscillation of what? You mention logic gates -- there, what oscillates is the voltage passing through the wires that connect the gates, correct? And voltage in a wire is certainly a characteristic of a component of the logic circuit (the circuit being the whole system.) Yes, an oscillation of voltage. Where did the oscillation come from? You take the components apart, and there is no oscillation to be seen. Put them together, and there it is. So the "atoms" of markets are, goods and services, and the intentions of agents. If you like. Where is the market price? But can you maintain that the prices of goods and services belong to a different category from an agent's intentions? Certainly.

63 ok pixy, you have proven that biochemistry is neccessary, but you have not proven that it is sufficient. can you do that proof? Nope. That proof - actually a theory - is referred to as an Operational Theory of Consciousness. It would explain in detail how the biochemistry of the brain produces consciousness, and we don't have one. What we do have is an immense body of correlations which point - without exception - in one direction. We know that consciousness arises from brain biochemistry. We don't know how, at least not in sufficient detail.

64 Let me try a different tack: I can get a computer to make accurate statements about its environment. I can even get it to take measurements, form hypotheses, test them, construct theories, and so on. (They might be trivial theories; I wouldn't know where to begin on writing a program that could develop General Relativity all by itself. But theories nonetheless.) And I can explain to you, right down to the level of Quantum Mechanics, how the computer is going about this. Is this not judgement? And if not, why not?

65 Oh, and what's more, I can do the same thing with a system that is entirely mechanical - as in Babbage's Difference Engine. It would be an absolute bugger to build and maintain, though.

66 To sum up: Judgement is a mechanical process. So is information (albeit a very much simpler one), thought, love, hope, the free market, the history of science, and this blog. And you and me, of course.

67 Somehow I'm not surprised to learn that Michael is not familiar with Claude Shannon's seminal work. How can anyone who's got even a passing understanding of Information Theory make the claim that "information" belongs to the same family as "significance", "meaning", and "purpose". Exactly the opposite: Shannon proved that information is a purely physical phenomenon.

68 To sum up: Judgement is a mechanical process. So is information (albeit a very much simpler one), thought, love, hope, the free market, the history of science, and this blog. And you and me, of course. ha! Neal Stephenson disagrees. "...but laws of physics and mathematics are like a coordinate system that runs in only one dimension. Perhaps there is another dimension perpendicular to it, invisible to those laws of physics, describing the same things with differnt rules....." Perhaps we need another dimension to describe consciousness, or perhaps another medium. Perhaps we need new metaphysicists.

69 Perhaps Neal Stephenson should stick to writing fiction.

70 His speculation on the mind in Snow Crash was fun, but it was basically nonsense. And so is that quote. It's Dualism, and it has the same problem Dualism always has: If you postulate some other realm, entirely separate from our own and not subject to the laws of physics, then it logically cannot interact with the physical world, and to all intents and purposes does not exist. Which is why dualists drink so much.

71 But it is fiction!

the quote is from Diamond Age.

Stephenson interview-- http://www.reason.com/0502/fe.mg.neal.shtml

a part i liked-- "One could argue that people like Leibniz and the others were able to come up with some good ideas because they weren’t afraid to think metaphysically. In those days, metaphysics was still a respected discipline and considered as worthwhile as mathematics. It got the stuffing kicked out of it through much of the 20th century and became a byword for mystical, obscurantist thinking, but in recent decades it has been rehabilitated somewhat. At bottom, anyone who asks questions like “Why does the universe seem to obey laws?” or “Why does mathematics work so well in modeling the physical universe?” is engaging in metaphysics. People like Newton and Leibniz were as well-equipped for this kind of thinking as anyone today, and so it is interesting to read and think about their metaphysics."

Don't you guys think that Science fiction predicts and informs science?

And, are we engaging in metaphysics in speculating about consciousness?

72

Somehow I'm not surprised to learn that Michael is not familiar with Claude Shannon's seminal work.

Allow me to quote from that seminal work: The fundamental problem of communication is that of reproducing at one point either exactly or approximately a message selected at another point. Frequently the messages have meaning; that is they refer to or are correlated according to some system with certain physical or conceptual entities. These semantic aspects of communication are irrelevant to the engineering problem. The significant aspect is that the actual message is one selected from a set of possible messages. Shannon did not prove "that information is a purely physical phenomenon." Instead he restricted his subject to those aspects of information which are purely physical, leaving out the "semantic aspects", which are not. The researchers in bioinformatics restrict themselves in a very similar way, studying sequences of DNA bases and amino acids as abstract data, without considering how the genes and proteins participate in chemical reactions. Bioinformatics is useful and important, but nobody would expect a complete description of biological functions to arise from it; part of the data needed for such a description has been intentionally left out. "Information theory", Shannon's theory, is in the same boat: useful and important as it is, it is, by Shannon's express intention, not a theory of knowledge.

73 Instead he restricted his subject to those aspects of information which are purely physical, leaving out the "semantic aspects", which are not. The point being, semantics is syntax. The only way for semantics to exist or to act is through syntax.These semantic aspects of communication are irrelevant to the engineering problem.When he said irrelevant, he meant it. "Information theory", Shannon's theory, is in the same boat: useful and important as it is, it is, by Shannon's express intention, not a theory of knowledge. Doesn't matter. We're not talking about knowledge, we're talking about information. Knowledge is like semantics: It only exists in information, and it is irrelevant to the engineering problem (i.e. explaining how things work).

74

I can get a computer to make accurate statements about its environment. I can even get it to take measurements, form hypotheses, test them, construct theories, and so on. ... Is this not judgement? And if not, why not?

At the current state of the art, you cannot, in point of fact, do all of these things. Forming and testing hypotheses, and constructing theories, are faculties beyond our present ability to teach to a computer. Now, it is possible to teach a computer to assess a list of effects (e.g. medical symptoms) and produce a probable cause of those effects. But the algorithms used for this (usually a Bayesian logic engine) do not give rise to new judgements of the scientific type: no expert system ever built will assert that "XYZ is impossible", unless its builders told it so. We can, at present, teach a computer to spot a statistical correlation -- but correlation is not causation, as every scientist knows.

You will no doubt say that I'm doing "judgement of the gaps" now. Not so. We always knew, long before the first expert systems, that diagnosis could be, to a large degree, mechanized; that known problems, with their list of symptoms, could be catalogued. And we also knew that anyone who depended solely on the catalog would be stumped by an unknown problem -- to solve those you need scientific judgement. The behavior of expert systems exactly matches that of a pure catalog-reader: solving known problems easily, and baffled by the unknown.

75 Forming and testing hypotheses, and constructing theories, are faculties beyond our present ability to teach to a computer. Nope. It's done all the time. Focus Forecasting is a simple example, but there are far more complex ones in actual use, let alone research. (And I have, in point of fact, written a Focus Forecasting system.) We can, at present, teach a computer to spot a statistical correlation -- but correlation is not causation, as every scientist knows. Which is irrelevant, because all you ever get is correlations. It's the theory that specifies causation, and theories are only ever provisional. Can a computer form a hypothesis based on a correlation? Of course it can. Having found the correlation, all it has to do is assume that it is causation. Can it test that? Of course it can. The behavior of expert systems exactly matches that of a pure catalog-reader: solving known problems easily, and baffled by the unknown. Where the problem actually lies is in undefined causes. The computer is working from a model of the universe, not from the universe itself. If the model is incomplete, and you feed in a problem from the real world, then the cause may not be reflected in the model. That's hardly a surprise; you've just broken the assumption of Naturalism as it applies to the program.

76

That proof - actually a theory - is referred to as an Operational Theory of Consciousness. It would explain in detail how the biochemistry of the brain produces consciousness, and we don't have one. What we do have is an immense body of correlations which point - without exception - in one direction. We know that consciousness arises from brain biochemistry. We don't know how, at least not in sufficient detail.

Ah, Pixy. That "immense body of correlations" shows that biochemistry is among the causes of human consciousness. Precisely because we lack an operational theory of consciousness, we cannot state with any confidence that biochemistry is the sole cause. That's exactly the fallacy the apothegm "correlation is not causation" warns against.

By the way, I don't drink :)

77 That "immense body of correlations" shows that biochemistry is among the causes of human consciousness. Correct. Lacking a theory providing a plausible and detailed causal link between biochemistry and consciousness, we do need to keep in mind that all we have is 7,000 years worth of data all pointing directly to the fact that in ever case ever examined, consciousness behaves in all ways as though it were generated by brain biochemistry. Oh, and also that no other hypothesis can explain why beer makes you drunk. Precisely because we lack an operational theory of consciousness, we cannot state with any confidence that biochemistry is the sole cause. We can, however, state that no other cause ever put forward has made the slightest shred of sense when confronted with that immense body of correlations. In fact, I'll go further than that and say that we can indeed state with considerable confidence that biochemistry is the sole cause. That's the hypothesis, which is drawn from the correlations. It's a very strongly supported hypothesis, but it is not a full theory. But it doesn't need to be a full theory for us to make that statement. We could, of course, be wrong; but no-one has ever presented any reason to think so.

78

The point being, semantics is syntax. The only way for semantics to exist or to act is through syntax. [...] We're not talking about knowledge, we're talking about information. Knowledge is like semantics: It only exists in information, and it is irrelevant to the engineering problem (i.e. explaining how things work).

Two minor errors: You may prefer to talk about information, but I have been asking you about knowledge from the start. The domain of engineering is not explaining how things work, but exploiting how they work. Network engineers need not know or care what the data passing through the networks they make means. (That's what Shannon was saying.) But if you want to understand the message's sender -- if you're acting, that is, as a scientist -- the meaning of the message is vital to your enquiry.

And now for the major error: "Semantics is just syntax, because it only acts through syntax." I don't know if you have kept up with researches into animal behavior; but it appears that several nonhuman species (all social mammals -- wolves, apes, dolphins) are capable of reaching judgements about their environment, without being able to express them. For these animals, that is, semantics exists without syntax -- a thing you have declared to be impossible.

You should also consider the entities of mathematics. Since these act on matter only through information (e.g. mathematical papers and computations) you would have to assert that they just are the information through which they act: that mathematics is mathematical syntax. However, from this it would follow that the truth of a mathematical theorem is just its provability -- the very proposition that Goedel disproved in 1931.

That's two reasons (from quite different domains, notice) why equating meaning to information is not plausible.

Lacking a theory providing a plausible and detailed causal link between biochemistry and consciousness, we do need to keep in mind that all we have is 7,000 years worth of data all pointing directly to the fact that in ever case ever examined, consciousness behaves in all ways as though it were generated by brain biochemistry.

You keep on repeating this. I do not think it means what you think it means.

Allow me, please, another quote:Again, did I know nothing about the movement of bodies, except what the theory of gravitation supplies, were I simply absorbed in that theory so as to make it measure all motion on earth and in the sky, I should indeed come to many right conclusions, I should hit off many important facts, ascertain many existing relations, and correct many popular errors: I should scout and ridicule with great success the old notion, that light bodies flew up and heavy bodies fell down; but I should go on with equal confidence to deny the phenomenon of capillary attraction. Here I should be wrong, but only because I carried out my science irrespectively of other sciences.

79 Two minor errors: You may prefer to talk about information, but I have been asking you about knowledge from the start. Knowledge is a subclass of information. The advantage of talking about information is that information is well-defined, and knowledge isn't. The domain of engineering is not explaining how things work, but exploiting how they work. Alright then: Knowledge is like semantics: It only exists in information, and it is irrelevant to the scientific problem (i.e. explaining how things work). I don't know if you have kept up with researches into animal behavior; but it appears that several nonhuman species (all social mammals -- wolves, apes, dolphins) are capable of reaching judgements about their environment Well, sure. Anyone who has kept anything more intelligent than a mouse as a pet knows this. without being able to express them. And anyone who has kept anything more intelligent than a mouse as a pet knows that this is false. For these animals, that is, semantics exists without syntax -- a thing you have declared to be impossible. Nope. For animals, semantics exists without spoken language, which is a completely different matter. The syntax is still there. Spoken language is just one specific form of syntax. However, from this it would follow that the truth of a mathematical theorem is just its provability No, that does not follow. A mathematical theorem does not stand alone, but is embedded in the syntax of mathematics. If you examine a theorem without the foundation of mathematics or logic, it doesn't mean much of anything. That's two reasons (from quite different domains, notice) why equating meaning to information is not plausible. Neither of which stands up to any sort of examination. You keep on repeating this. I do not think it means what you think it means. Means what it says: That given the collected data (which is truly vast in scope), the only plausible explanation is that consciousness is generated by the biochemical functioning of the material brain, and that quantum ghosts, souls, magic brain fairies and such like simply do not exist. Here I should be wrong, but only because I carried out my science irrespectively of other sciences. And there you go. Physics tells us that consciousness is a biochemical process. So do chemistry and biochemistry. So do medicine and psychology. Geology and astronomy doen't really say much on the subject, except to report in that Naturalism is working out just fine thanks. What science do you think I have neglected?

80

"... several nonhuman species (all social mammals -- wolves, apes, dolphins) are capable of reaching judgements about their environment without being able to express them. For these animals, that is, semantics exists without syntax -- a thing you have declared to be impossible." Nope. For animals, semantics exists without spoken language, which is a completely different matter. The syntax is still there. Spoken language is just one specific form of syntax.

I assume you mean that the outward behavior of the social animals forms a "syntax". The trouble is, we could not deduce from only the outward behavior of the animals that they reach judgements; we infer that some animals reach judgements by analogy from our own experience as judgement-makers. We take our own minds as a model for the animals' and predict their actions accordingly. We do not find the model in their actions -- the "semantics" is not in the "syntax".

We make the same inference, incidentally, about other human beings: I know that other people reach judgements because, were I in their situation, my behavior as guided by judgements would resemble theirs as I observe it. If I did not have experience of forming judgements, the observable actions of other humans would be unintelligible.

"from [that mathematics is mathematical syntax] it would follow that the truth of a mathematical theorem is just its provability" No, that does not follow. A mathematical theorem does not stand alone, but is embedded in the syntax of mathematics. If you examine a theorem without the foundation of mathematics or logic, it doesn't mean much of anything.

If you suppose you've disagreed with me here, you are mistaken.

What science do you think I have neglected?

The science of consciousness and mentality. Yes, yes, there is no theory of consciousness -- that only means the science is in the empirical stage, disorganized and without a principle. Was there no science of biology before Darwin?

Your problem is, you take an engineer's view of the sciences; you think of the great scientific theories as established truths, to be accepted and turned to use. You are so impressed by the vast extent of phenomena that those theories cover that, though the scientists hold them provisionally and within the limits of observation, you are quite sure that they explain everything. And so, when faced with something the theories don't cover, you assimilate it as far as possible to something they do cover, and dismiss what's left over as "irrelevant to the scientific problem". You exemplify, in fact, the fallacy John Henry Newman spoke of:Men, whose life lies in the cultivation of one science, or the exercise of one method of thought, have no more right, though they have often more ambition, to generalize upon the basis of their own pursuit but beyond its range, than the schoolboy or the ploughman to judge of a Prime Minister. But they must have something to say on every subject; habit, fashion, the public require it of them: and, if so, they can only give sentence according to their knowledge. You might think this ought to make such a person modest in his enunciations; not so: too often it happens that, in proportion to the narrowness of his knowledge, is, not his distrust of it, but the deep hold it has upon him, his absolute conviction of his own conclusions, and his positiveness in maintaining them. He has the obstinacy of the bigot, whom he scorns, without the bigot's apology, that he has been taught, as he thinks, his doctrine from heaven. Thus he becomes, what is commonly called, a man of one idea; which properly means a man of one science, and of the view, partly true, but subordinate, partly false, which is all that can proceed out of any thing so partial. Hence it is that we have the principles of utility, of combination, of progress, of philanthropy, or, in material sciences, comparative anatomy, phrenology, electricity, exalted into leading ideas, and keys, if not of all knowledge, at least of many things more than belong to them,— principles, all of them true to a certain point, yet all degenerating into error and quackery, because they are carried to excess, viz. at the point where they require interpretation and restraint from other quarters, and because they are employed to do what is simply too much for them, inasmuch as a little science is not deep philosophy.

81 Wow, is this thread still going? I think there's a relatively simple way to look at consciousness without getting into a lot of abstraction, which is to start at things that are not very conscious (your thermostat), and move gradually up through the spectra of things that demonstrate increasingly greater levels of consciousness (single-celled organisms, tiny multicellular organisms, insects, lizards, your cats, yourself), then ask: what makes some things more conscious than others? Naturalism eventually gave birth to empriricism, which is probably the most powerful tool ever devised by man. It gave us the entire modern world.

82 'Kay, let's take TallDave's advice, and start at the bottom, or near the bottom. Let's start with something we understand, like say, DNA! and break the processes down with quantum biology and quantum chemistry until we get to the lowest level. Then we can simulate consciousness and categorize it as one of Pixy's isms. ;-)