Much of your argument centers around your belief that neural networks are a different mode of computation than Turing machines. I do not believe you are correct but there's a fair amount of confusion of this point online. Before replying to your specific points I'll lay out my understanding, and if you or anyone else can clarify or amend my thoughts, please do.
* First, there are Turing machines (TMs). The
Church-Turing thesis says that anything we can compute, can be computed by a TM. This is an eighty year old core idea in computer science that has never been refuted. If tomorrow morning professor so-and-so in Helsinki publishes a paper called, "A mode of computation that's not a TM," it would rock the computer science world and it would make the popular media. "80 year old computer theory debunked," etc.
This hasn't happened. As far as anyone in the world knows, everything that we would call a computation can be implemented as a TM.
* Real-world neural nets are TMs. This must be true; if not, Church-Turing would be broken and we'd all have heard about it.
What is a neural net (NN)? It consists of a set of nodes, each assigned a numeric weight. Then we apply some logic: If the weight of this node is such and so and its immediate neighbors are such and so and their neighbors are such and so, then do something. This is perfectly conventional programming. The greatest weak AI in the world, such as AlphaGo Zero, is a conventional computer program implemented on conventional hardware. A real-world implementation of a TM.
To be sure, neural nets are very clever ways go
organize a conventional computation. But they are conventional computations nonetheless.
* Theorestical neural nets. In the abstract model, the numeric weights of the nodes can be real numbers. Since in general it takes an infinite amount of information to specify a real number, there are no real-world implementations of theoretical NNs. I'm not aware of the theory of computation behind NN and how they relate to Church-Turing.
* Wetware NNs such as the brain. Since brains are physical, even if they are NN's, they are TMs. Moreover, the idea that the mind implemented by the brain is a NN is a speculative idea. Nobody has proof. There's no reason to believe a mind/brain is a TM and plenty of reasons to doubt it.
I'm definitely not claiming computationalism - or at least not Turing machine computation as you seem to suggest. The mainstream neuroscience view - since Sherrington's "enchanted loom" or Hebbs's learning networks - is some kind of neural net form of "computation". — apokrisis
Any physical implmentation of a NN is a TM. If you disagree then you either believe the Church-Turing thesis has been falsified (which it hasn't) or that the brain contains nodes that can represent arbitrary real numbers (absurd) or you have some other justification for your claim. Please provide such justification.
As far as what constitutes mainstream neuroscience, I'm not qualified to judge. I hope you would agree that the opinions of neuroscientists donot constitute a refutation of Church-Turing, merely ignorance of it.
And more to the point, it is mainstream to emphasise that the brain is involved in informational activity, not merely biochemical activity. — apokrisis
It may be mainstream speculation, but it is certainly not mainstream established fact. But again, why are you so hung up on the opinions of neuroscientists? Since any real-world NN must be implemented as a TM, the burden is on you to explain yourself.
Otherwise why is neuroscience interested in discovering the secrets of the neural code, or brain's processing architecture? — apokrisis
How does that prove a real-world NN isn't a TM? You are committed to your
argumentum ad populum but you don't seem to be able to reason on your own.
It knows the biophysics of what makes a neuron fire. But how that firing then represents or symbolises something with felt meaning is the big question. — apokrisis
Oh, I thought it was a computer program as you keep claiming. Or a NN, which is just a particular kind of computer program. Now you admit that we DON'T understand how firing neurons give rise to mind. Well then at last we agree.
And that can only be approached in terms of something other than a biochemical materialism. — apokrisis
Why?
It demands a semiotic or information theoretic framework. — apokrisis
Why?
Which in turn has already considered Turing computation and found it not the answer. — apokrisis
Funny you should say that, since many people (wrongly) believe the mind is literally a TM computation. But if the mind is ANY kind of computation, you have to explain how it could be a computation yet not be a TM. This point does not seem to be appreciated in the literature
So broadly speaking, neuroscientists think thoughts are informational processes and not biochemical events. — apokrisis
Some do, some don't. Some scientists used to think heat was caused by phlogiston. What of it? You are continually trying to substitute claims about the opinions of some neuroscientists for thinking things through on your own.
At the same time, they don't think the brain is literally a Turing machine or programmable computer. That might be a helpful analogy, like calling the eye a camera. But just as quickly, the caveats would begin. — apokrisis
I'm glad that you agree with me on at least this point. The problem is that
there is no other mode of computation as far as we know.
Computers are machines. They are devices that construct patterns. So yes, of course, human minds seem to operate in a fundamentally different fashion. We can grasp the whole of some pattern. We can understand it "organically" as a system of constraints, rather than as an atomistic construction. — apokrisis
If you agree with me why do you keep trying to disagree? I have no idea what your point is. You go back and forth on your own opinion.
Our abductive or intuitive approach to reasoning begins with this ability to see the whole that "stands behind" the part. We can make inferences to the best explanation. And then, having framed an axiom or hypothesis, we are also quite good at deducing consequences and confirming by observation. — apokrisis
Yes. Which neither confirms nor denies that mind is a computation, since even the weak AI's are quite impressive these days in seeing the whole, as in facial recognition.
So when it comes to mathematical truth, that is what we think we are doing. We notice something about the world. We then leap towards some rational principle that could "stand behind" this something as its more general constraint. — apokrisis
You are eloquently agreeing with my point.
Turing machines are really bad at making such a holistic generalisation. — apokrisis
These days, strangely and counterintuitively, TMs are incredibly good at generalization and "gestalt," at least in constrained domains.
AlphaGo Zero is mind-blowing in its philosophical implications and AlphaGo Zero is a TM.
Neural network computers are our attempt to build machines that are good at implementing this precise inferential leap. — apokrisis
Agreed. NN's are a clever way of organizing a conventional TM. But every NN is implemented as a TM. They're computer programs implemented on conventional hardware. Please tell me you understand this point. There are no magic NN computers. They're NN algorithms implemented on TMs.
Yeah. I don't claim complete substrate independence. But then my "computationalism" is a semiotic or embodied one. The whole point is that it hinges on a separation which then allows an interaction. — apokrisis
If it's a computation then it's a TM. You need to deal with this point.
A Turing machine does not self-replicate. — apokrisis
Neither does a person without children. What does that have to do with the subject at hand? Red herring.
A Turing machine does not have to manage its material flows or compete with other TMs. — apokrisis
Ever hear of
core wars? Oldtime hackers used to write programs that would compete with each other for machine resources. Of course TMs can be programmed to compete with other TMs.
But a living thing is all about regulating its physics with information. — apokrisis
You are confusing the issue by bringing up living things. Nothing to do with the subject at hand.
So an independence from physical substrate (an epistemic cut) is required by life and mind. — apokrisis
I don't see why. Searle believes mind is a function of the physical brain, just not a computational one. You don't need mysticism or duality.
But only so as to be able to regulate that physics - bend it in the direction which is making the autopoietic wholeness that is "an organism". — apokrisis
Autopoeietic. Whatever. What's that mean? I could look it up but I'd like you to explain this in your own words what your point is. NNs are TMs and if you think the mind is a computation then you think the mind is a TM. You have to deal with that by denying it (with evidence) or accepting it.
Yes, you can measure one side of the computational story in terms of entropy production. But how do you measure the other side of the story in terms of "negentropy" production? The fact that your computer runs either hotter or colder doesn't say much about whether its eventual output is righter or wronger. — apokrisis
I don't follow the relevance of that para.
We are labouring the point. If you really can't see the difference between syntax and semantics by now, things are likely hopeless. — apokrisis
If you don't see the difference between fish and bicycles, things are likely hopeless. WTF? You think I don't know the difference between syntax and semantics? You're flailing.
You keep talking about the physical events as if they are the informational processes. — apokrisis
No no. But informational processes ARE physical events. Running Euclid's algorithm in a supercomputer or with pencil and paper are physical processes [not events]. They require energy and output heat. The description of the algorithm, the program, does not compute anything.
Of course a neuron or a transistor or a membrane receptor or a speedometer can be described in terms of their "physics". But it is hardly the level of description that explains "the process" which we are interested in. — apokrisis
It doesn't explain mind. It only points out that you don't need duality to explain computation. Computation is a physical process. [And not the converse as you tried to claim I said earlier].
To reduce functional or informational processes to atomistic material events becomes a nonsense. — apokrisis
Why? Who's the dualist now? What kind of mystical process are you believing in? If my mind is not a function of my physical brain, what do you think it is, exactly? Are you a dualist or not?
Especially for true computationalism. The only time we are interested in the physics of a logic gate is when it doesn't behave like a logic gate - that is when it has some uncontrolled physical process going on. — apokrisis
Uncontrolled physical process? You know you are not speaking coherently these past few paragraphs. You're flailing randomly.
So algorithms are extreme mechanistic dualism in fact. — apokrisis
Dualism, why? I program a computer to add 2 + 2, it outputs 4. Where is the dualism? The computer inputs electricity, outputs heat, and performs a computation. I really don't understand your mysticism around this very commonplace and well-understood phenomenon of computation.
You don't even have to run a programme for it to "have a result". — apokrisis
That's just wrong. If I write down the Euclidean algorithm, it has no result. Only when I implement the program on a physical substrate and execute the algorithm does it produce a result. If you don't understand this there really is nothing to talk about.
The result could only be different if the physics of the real world somehow intruded, And then we would say the computer had a bug. It over-heated or something. — apokrisis
What of it? You just claimed a program need not be executed to produce a result. That's "not even wrong." Its a profound misunderstanding of computation.
And maths is kind of like that. We imagine it as transcendent and eternal truths - things that would be true without ever needing the reality of physical instantiation. Pure information. — apokrisis
Ok we're Platonists today. Fair enough. But where do these truths live? You are quite the mystic.
It is crazy to talk of Euclidean maths as existing in some geezer's long dead brain. — apokrisis
Really? Crazy? That the best you can do in lieu of an actual argument? You haven't made a single rational argument in this entire post. I don't think you have one.
Why do you interpret that as a mystical statement? My point was that it is not a mystery because it is what you would expect from principles of physicalist symmetry. If every kind of difference gets cancelled (as the negatives erase the positives) then what you are left with is the mid-point balance. It would be natural to expect "flatness" as the emergent limit state. — apokrisis
Nonsense. Mathematical nonsense and physical nonsense. You must have missed the Einstenian revolution. It's not 1900 anymore.
Well it is your choice to ignore what we know to be fundamental in preference for what we know to be emergent. — apokrisis
Ah, emergence. Another murky concept. Hydrogen's not wet and oxygen's not wet but water is wet. Zowie, cosmic.
I honestly have no idea what you are going on about. I really don't think you are making any sense at all.
Fine. The philosophical issue here is not the pragmatics of mathematical research. And I even agree that mathematical research - in being an informational theoretic exercise ... — apokrisis
Didn't I already remind you earlier that Gödel disproved that math is an information-theoretic exercise? Why are you doubling down on a claim I've already falsified?
Maths doesn't really want to even concern itself with geometry - the physical constraints of space - let alone with actual materiality, or the constraints of energy, the possibilities of change. So - as institutional habit - integers are as real as rocks. — apokrisis
You seem to be back in 1840, railing against the great discovery of non-Euclidean geometry. Is that your complaint? That math isn't physics? I'm sure the physicists agree with you.
Except they are then ... ideas? Constructs? Thoughts in the head? — apokrisis
The nature of mathematical truth is indeed an open question.
You seem to want it both ways. And that winds up in Platonism. — apokrisis
I just want you to say something that's reasonably on topic and that makes some sort of sense. I have no idea what you're going on about here.
That is why my own position is the semiotic one where the integers are the ideal limits on materiality. — apokrisis
"the integers are the ideal limits on materiality" -- This is supposed to make logical sense to me? Is this some sort of postmodern theory? I confess I don't take postmodern mathematical musings very seriously. Perhaps you do. If you would take the time to explain what you mean by "the integers are the ideal limits on materiality" then perhaps I'd learn something.
That is a formula of words that both accepts a strong difference and a strong connection between the two sides of the semiotic equation. Information is real if it is causal. And being an actual limit on material freedom is pretty clearly causal. — apokrisis
You sound like a raving postmodernist. Perhaps you are a postmodernist and I'm insuffiently appreciative of that point of view. That may well be the case.
See earlier where I spoke about abductive reasoning and our ability to make inferential leaps. Gödel validates my approach here. The failure of logical atomism is the solid ground for the holist. It is why a semiotic approach to reality is justified. — apokrisis
Semiotic. Whatever. Explain yourself clearly if you can. Can you?
You mentioned pi. I am just highlighting how the usual woo-woo aspect - the fact that there is just this "one number" picked at random out of all the numbers on the number-line - masks a bigger story. The woo-woo evaporates when you see there is a "material" process that picks out a value for "being flat". Two kinds of possible curvature had a mid-point balance. Pi is a number that emerges due to something more holistic going on. The fact that it emerges "right there" on the number-line is not some kind of weird magic. — apokrisis
Tell me something. What is the true value of 3? And why does it emerge "right there" on the number line, halfway between 2 and 4?
It is even easier to see with other constant like e that are directly derived from growth processes. There the contrasting actions that produce the emergent ratio are in plain sight. It is funny that e should be 2.71828. — apokrisis
It's hilarious.
But then that becomes obvious when it is realised that growth always has to start from some thing that is just itself 1. There is no reason to think of e as anything but natural after that. — apokrisis
Mystical word salad.
But I am not Kantian, except in a loose sense. I'm Peircean in the way Peirce fixed Kant. — apokrisis
Maybe we better not go there. You remember how that went last time. Although I suspect this is the problem. You are arguing from a very particular point of view.
But you are not willing or able to explain yourself. So everything that anyone says is wrong from your point of view, and you're right, and you're condescending, but you can't explain your ideas in everyday English. And in my experience, you don't really understand a lot of the ideas whose terminology you carelessly sling around.
And I'm arguing flatness is special as the mid-point of opposing extremes of curvature. It has physically important properties too. Only flat geometries preserve invariance under transformations of scale. That is a really important emergent property when it comes to things like Universes. — apokrisis
Oh to be back in 1840 when Euclidian geometry was given to us by God.
And as I repeat, it is very important metaphysically that absolute scale invariance only appears at a particular numeric value of pi. That is how a Universe is even possible. — apokrisis
What is the specific numeric value of 3? I already explained to you that pi is a particular real number whose value does not change and has nothing to do with geometry.
So you are focused on the triviality of pi being given some particular position on the number line - look guys, its 3.141592653589793238462643383279502884197169399375105820974944592307816406286 208998628034825342117067982148086513282306647093844609550582231725359408 ...
And that is what makes folk go woo. It seems both weirdly specific and weirdly random. There seems no natural reason for the value. — apokrisis
What is the natural reason for the value of 3?
But it's a ratio derived from the radius being granted as the natural unit. Let's call the radius 1. Let's get a grip on this weird thing called curvature by starting with the "most natural part of the story" - a line segment. That gets to be "1" on the number-line. — apokrisis
Bearing in mind that the unit distance is arbitrary. A linear scaling factor would make no difference.
Well, as I say, once mathematicians woke up to the fact that flatness was a rather special case of curvature, and once physicists in turn woke up to the fact that scale invariance was essential to any kind of workable Universe (its called rather grandly the cosmological principle), well, maybe it is the ratio that should be called "1". A straight line segment is only a natural unit in the context of an already flat space which supports unlimited scale transformations. It depends on the emergent fact of parallel lines or infinite rays being an actual possibility. — apokrisis
I have no doubt that what you're saying makes perfect sense to you. It makes no sense to me. I don't get where you're coming from.
I am being anti-mystical in pointing out the very physical basis of pi as a number. It is a ratio that picks out a critical geometric balance. — apokrisis
Even if I grant your point, what of it? Why are you going on about pi?
The number 3 is trivial by comparison. — apokrisis
Then explain to me what mystical geometric balance causes 3 to have the exact value that is has.
Well there are physical arguments for why the geometry of universes are optimal if they have just three orthogonal spatial directions. But 3 as a member of the integers has no numeric specialness by design. The special or natural numbers are 1 and 0. We see this in the symmetries captured by identity operations. There is something basic or universal when we hit the bedrock that is a symmetry or invariance. — apokrisis
Look, maybe Pearce said all this. I haven't the knowledge to comment. You seem to know a lot about this, or at least you know the buzzwords. It's pointless to argue with you about it.
You would call it a mystical fact perhaps. I see it as quite reasonable and self-explanatory. — apokrisis
I can no longer converse with you on this point.
Nope. At least not your notion of computation as Turing machine/programmable computation. — apokrisis
What is your model of computation? And how do you square it with the Church-Turing thesis?
I take an information theoretic perspective. And more specifically, a semiotic one. In technology terms, neural networks come the closest to implementing that notion of computation. — apokrisis
Yes and any NN that can exist in the physical world is a TM. You have to refute this or accept it. I'm perfectly willing to be shown wrong, since I'd learn something. Do it.
And numbers vs rocks is a distinction that relies on a classical metaphysics - one in which the divide between observers and observables does not present an epistemic difficulty. The epistemic cut - the necessary separation of the information from the physics - can be treated as an ontological fact. — apokrisis
You are the buzzword king. You do have a hard time translating your buzzwords into ideas that you can explain to people.
So my positions on both "mind is a computation" and "reality is classical" are the same. — apokrisis
If mind is a computation and if it's implemented on a physical brain, then it's a TM.
Semiotics starts from the view that there is no fundamental ontic division of observers and observables. But that is also the division which must emerge via some epistemic cut. It is the basis of intelligibility. And even the Universe can only exist to the degree it hangs together in intelligible fashion. — apokrisis
I yield to your facility with buzzwords.
Hence why maths tends to be unreasonably effective at describing the Universe. Or being in general. — apokrisis
It's a puzzler alright. Or perhaps math is only telling us something about our own minds, and not the universe at large. That's a possibility too.
Labouring the point still, but I'm sorry. I'm not a computationalist in the sense you are hoping for. — apokrisis
Well we're back to the NN = TM issue again. That's the core issue here. You think there's a mode of computation that is not a TM and that can be physically implemented in the brain. This I deny. Computer science is on my side I believe. I could be wrong. I await clarity.
Indeed, that was what I was accusing you of. You seem to believe reality is a machine. An account of physical events is sufficient. — apokrisis
I have never believed that and I strenuously oppose it. But it's normal for you to think I've said the opposite of what I think I said. We may just have to live with that.
But yes, you also seem to say the opposite. This is a symptom that your metaphysics is "commonsensical" and not well thought out. — apokrisis
I admit I'm not much of a philosopher. If you ever took the trouble to explain your points of view to me, I'd learn something. But that never seems to happen.
Again, bully for mathematicians. Bully for engineers. Bully even for most physicists (as very few are employed in frontier theory construction).
But it is curious to be complaining about metaphysics where metaphysics is appropriate. — apokrisis
You were complaining that mathematicians aren't in a state of "epistemic shock." I pointed out that when mathematicians are doing math, they're not doing philosophy. You want people to do their jobs, not get lost in the wonder of it all.
And so far you haven't put forward any clear exposition of your own epistemic position, let alone given a clear justification for it. — apokrisis
I haven't got much of an epistemic position today. I vaguely recall originally making some minor point which I no longer remember. I don't believe the mind is a TM and I don't believe real-world NN's are anything other than TMs. That's plenty of position. By the way don't you mean ontic position? What is, rather than how we know what is? I'm even confused about your nonstandard use of "epistemic." I never understand anything you say.
You just hoped to be able to label me with some obviously weak ontology that I spend most of my time arguing against. — apokrisis
LOL. And you are doing the same to me.
Bottom line, why don't you just explain to me why you think a real-world NN is anything other than a TM. That's at least one subject that might be of interest, and it's one where we're reasonably on the same page even though we have different opinions.