While intelligence is not difficult to explain as an emergent property of an organized collection of neurons, conscious experience itself is. Nothing about the individual behavior of neurons seems to predict that conscious experience will arise when enough of them are interconnected in a certain way.

Accepted. My questions: To what do you attribute the 'emergence' of conscious experience from physical brains? What are the "simple but nonlinear rules" that account for consciousness, and what is the causal mechanism?

Finally, doesn't it strike you as a bit ironic to criticize someone for being unclear when you pepper your own statements with entirely unnecessary and irrelevant references to lightcones, Hamiltonians, and renormalization?

Not at all. My statements were quite clear as well, yet rather than try to understand my context, you chose instead to complain that I didn't understand yours. It works both ways. Let's see if we can rectify that. Answering the above three questions would be a good start.

If you challenge, it would be nice to have a clear idea of what your position is. You tell me I'm misunderstanding your position, and you obviously misunderstand mine. Go ahead and spell it out. It would save a lot of space.

I gave Joy the benefit of the doubt and re-examined the thread, looking for places where I contributed to her misunderstanding by failing to "spell out" my position. For each case where she mistook my stance, I've excerpted an earlier statement where I address the misunderstood topic.

Here are the results:

Joy wrote:

You assume that if we added up the number of neurons and multiplied by the number of brain 'modules' dedicated to certain tasks of information processing, consciousness must 'emerge' as a matter of physical course.

What I wrote, earlier in the thread:

While intelligence is not difficult to explain as an emergent property of an organized collection of neurons, conscious experience itself is. Nothing about the individual behavior of neurons seems to predict that conscious experience will arise when enough of them are interconnected in a certain way.

Joy wrote:

You don't believe in emergence as supervenience…

And:

Supervenience is top-down causation.

Here the problem is not any vagueness on my part, but rather Joy's misunderstanding of the definition of supervenience as contained in the very source she cites, the Stanford Encyclopedia of Philosophy:

A set of properties A supervenes upon another set B just in case no two things can differ with respect to A-properties without also differing with respect to their B-properties.

Nothing about this definition mandates that supervenience is top-down causation, as Joy claims.

Joy wrote:

…and you don't believe that any of it reduces to nonlinear dynamics. Noted.

What I wrote, earlier in the thread:

All of the weirdness of chaos theory, for example, results from the nonlinearity of the underlying processes. Zoom in on any portion of a chaotic process and you'll see simple (but nonlinear) rules being applied in a straightforward way, over and over. Absolutely no magic there.

So you see, Joy, the statements are quite clear. The problem is on the receiving end. Slow down, comprehend your opponents' positions, and you might be able to respond meaningfully rather than tilting at windmills all the time.

Finally, doesn't it strike you as a bit ironic to criticize someone for being unclear when you pepper your own statements with entirely unnecessary and irrelevant references to lightcones, Hamiltonians, and renormalization?

Physician, heal thyself.

Also, nonlinearity is not an attempt to make chaotic systems predictable. Rather, it demonstrates and explains their unpredictability.

We already know about unpredictability. We assess it probablistically, and have been doing so for almost a century. Works pretty well in a number of applications. As Macht points out in his blog Emergent Properties, Abstraction, and Reductionism, the abstractions can get so generalized that they lose whatever explanatory power the original conception might have had in certain (specified) applications. Physics has a problem with this tendency to overgeneralize, but in many applications it's been immensely useful… FAPP.

Unpredictability isn't very useful to us, unless at some level it becomes predictable. On the level of Schrodinger's poor cat, material 'cat-ness' extends in time very predictably (something probability on the single particle level doesn't explain, so it's mostly ignored). Spontaneous combustion of cats isn't that common, and nobody I've ever heard of has ever seen a cat turn into a shrubbery or a herring.

Singularities are not the inevitable result of nonlinearity.

That's not what I said. I said that nonlinearity works (or tries to work) around singularities that arise using other methods. Sometimes it works. Sometimes it doesn't.

The consensus among physicists is that while the wave function is deterministic, its collapse is inherently probabilistic.

Reality must be presumed 'real' in order for any of our abstractions to work… FAPP. Problems arise mostly when abstractions are taken too seriously.

Viscosity is not a property of an individual molecule, but of many molecules organized as a fluid. Yet no "magic" is required to produce viscosity "” each molecule simply has to follow the same unmagical physical laws it follows when isolated.

I know. I haven't claimed otherwise.

Where did you get that idea?

From your posts. All I can do is parse the words you write through my processors. If I have it wrong, try re-phrasing. That sometimes works.

Are you sure you're not projecting your own discomfort at being challenged?

If you challenge, it would be nice to have a clear idea of what your position is. You tell me I'm misunderstanding your position, and you obviously misunderstand mine. Go ahead and spell it out. It would save a lot of space.

It's basically an attempt to make predictable (at least in a stochastic sense) that which is not predictable due to the limitations on our knowledge of initial state of the system, and all subsequent effectual interactions in the past lightcone.

Joy,

Don't confuse nonlinearity with chaos. Nonlinearity is a necessary but insufficient condition for producing chaotic behavior. There are many nonlinear systems which are not chaotic, e.g. my audio amplifier example.

Also, nonlinearity is not an attempt to make chaotic systems predictable. Rather, it demonstrates and explains their unpredictability.

A way to justify getting around the singularities in the equations that have usually been 'renormalized' away (cheating), under the baseline assumption that dynamical systems - even chaotic ones - are at root deterministic.

Singularities are not the inevitable result of nonlinearity. F(x) = x^2 is nonlinear, but it has no singularities.

This can easily become a tautology, and often does. "If only we knew everything [omniscient], we'd know everything!"

All of mathematics is tautological in this sense. "2 + 2 = 4" is a tautology. This doesn't diminish the usefulness of mathematics at all.

Nonlinear approaches to prediction for something as multi-complex as Schrodinger's cat seem pretty ridiculous to me, when other methods work as well (come up with the same probability) with much less wasted effort. Figuring the Hamiltonians (degrees of freedom) for every piece-part is cumbersome. Odds are 50-50 no matter how you do the math. Still, a non-linear approach lets the aproachees believe they're working with a fundamentally deterministic system, so they don't have to think about the idea that maybe it's indeterministic.

Who are these people who claim that Schrödinger's cat is a deterministic system? The consensus among physicists is that while the wave function is deterministic, its collapse is inherently probabilistic.

simply asserting that emergent properties arise in nonlinear fashion from the substrate in deterministic fashion ("if we only knew everything"¦") doesn't make it so.

Of course it doesn't. What makes nonlinearity successful as an explanation is that, like any successful scientific explanation, it is confirmed by experiment and observation.

Heck, the very definition of a "complex system" in nonlinear terms is just as magical as the definition of emergence (which nonlinear approaches are supposed to explain).

Complex Systems - Complex systems are spatially and/or temporally extended nonlinear systems characterized by collective properties associated with the system as a whole - and that are different from the characteristic behaviors of the constituent parts. [Emergent properties]

Viscosity is not a property of an individual molecule, but of many molecules organized as a fluid. Yet no "magic" is required to produce viscosity — each molecule simply has to follow the same unmagical physical laws it follows when isolated.

You don't believe in emergence as supervenience…

Not true. Where have I written any such thing?

[You] don't believe supervenience is downward causation* per its controlling agency over the collective substrate…

You cite the Stanford Encyclopedia of Philosophy's article on supervenience. Have you read it? It states that

A set of properties A supervenes upon another set B just in case no two things can differ with respect to A-properties without also differing with respect to their B-properties.

Nothing in that definition requires downward causation. Supervenience and downward causation are separate concepts.

, and you don't believe that any of it reduces to nonlinear dynamics. Noted.

Again, I have written nothing of the sort. Where did you get that idea?

Again, if it makes you uncomfortable to discuss the topic, don't.

It doesn't make me uncomfortable at all. Brain and mind are among my favorite topics.

Are you sure you're not projecting your own discomfort at being challenged?

How is consciousness explained by the properties of brain cells?

It's not. Though the 'strong' [eliminative] reductionist position very much wants it to be. Hence the connectionist models folks like Ramsey, Stich and Garon hope will someday provide 'plausible' - that means believable - explanation of mind as a physically determined phenomenon that will support the denial of belief-like states of mind.

Denial is not just a river in Egypt… §;o)

That quote seems to indicate that she believes there are "magical" properties associated with life, and that scientists invoke nonlinearity as a hand-waving non-explanation of these. You can hash it out with her if you wish.

I just have to read it to conclude there is a difference between an assertion of magical properties and her statement that there is an association between magical properties and life and Mind.

Laws of physics do not explain life's origins though.

That's debatable, but my assertion is about life, not life's origins.

If it is debateable then presumably you have a reference to specific laws of physics and how they are linked as causal generators of life

How is consciousness explained by the properties of brain cells?

We don't know. That's why it's called the Hard Problem. My assertion was about life, not consciousness.

Human life entails consciousness. If life is an emergent property of matter then so are humans and their consciousness right?

Of course organisms function according to laws of physics. Noone is contending otherwise.

It surprises me too, but Joy seems to be contending otherwise.

You quoted Joy as follows:

These terms are most often encountered in arguments about the magical properties that humans have always associated with life and Mind.

That quote seems to indicate that she believes there are "magical" properties associated with life, and that scientists invoke nonlinearity as a hand-waving non-explanation of these. You can hash it out with her if you wish.

Laws of physics do not explain life's origins though.

That's debatable, but my assertion is about life, not life's origins.

How is consciousness explained by the properties of brain cells?

We don't know. That's why it's called the Hard Problem. My assertion was about life, not consciousness.

Of course organisms function according to laws of physics. Noone is contending otherwise. Laws of physics do not explain life's origins though.

Therefore weak emergence is quite sufficient.

How is consciousness explained by the properties of brain cells?

Nonlinearity in physics is not about the "spontaneous emergence of things from inadequate substrates"

It's basically an attempt to make predictable (at least in a stochastic sense) that which is not predictable due to the limitations on our knowledge of initial state of the system, and all subsequent effectual interactions in the past lightcone. A way to justify getting around the singularities in the equations that have usually been 'renormalized' away (cheating), under the baseline assumption that dynamical systems - even chaotic ones - are at root deterministic.

This can easily become a tautology, and often does. "If only we knew everything [omniscient], we'd know everything!" It works fairly well to provide a range of prediction (like a point-spread) short-term for simple dynamic systems. Like FAPP predictions of gravitation in 3-body systems, for example. For much more dynamic constructs it's not better than any other method we ever developed, including cheating (it 'works', FAPP).

Nonlinear approaches to prediction for something as multi-complex as Schrodinger's cat seem pretty ridiculous to me, when other methods work as well (come up with the same probability) with much less wasted effort. Figuring the Hamiltonians (degrees of freedom) for every piece-part is cumbersome. Odds are 50-50 no matter how you do the math. Still, a non-linear approach lets the aproachees believe they're working with a fundamentally deterministic system, so they don't have to think about the idea that maybe it's indeterministic. Six of one, half a dozen of the other, and simply asserting that emergent properties arise in nonlinear fashion from the substrate in deterministic fashion ("if we only knew everything…") doesn't make it so.

It'll probably prove useful as an approach to what arguably *are* deterministic systems. I do not share the wishful thinking of reductionists that biological systems qualify, thus I think the application to biological systems is a mistake. You can of course disagree. Six of one, half a dozen of the other.

Totally causal. No magic. No "inadequate substrates."

You wish. The verdict on that hasn't come in yet, and isn't likely ever to come in, so I call it a "hung jury." Heck, the very definition of a "complex system" in nonlinear terms is just as magical as the definition of emergence (which nonlinear approaches are supposed to explain).

Complex Systems - Complex systems are spatially and/or temporally extended nonlinear systems characterized by collective properties associated with the system as a whole - and that are different from the characteristic behaviors of the constituent parts. [Emergent properties]

Only under what's known as "strong emergence" are emergent properties irreducible to the properties of the substrates. Strong emergence is accepted by a small number of scientists, including Robert Laughlin, but is rejected by most.

So what? How many of those "most" scientists are working directly in nonlinear science applied to biology, and how many are involved in the quest for consciousness? Appeal to authority [consensus] in this case is itself a misapplication. I am not "most," and I don't care what they believe.

The application to biology - and particularly to consciousness - is "strong." So that is of course what I'm talking about, given the title of this blog - Thinking About Thought and Belief. Did you read it? If so, why come back in panic to define-away the application very much applicable to the subject? That's a total waste of time, keith. If you don't want to discuss the subject of this blog, then don't post to it. Spamming it with your personal objections to the subject and terms is a distraction.

Note that the Hard Problem applies only to the problem of conscious experience, and not to the problem of the will or of intelligence. The latter two can be explained in terms of pure physical interactions, in a way that the former cannot (at least yet).

Well duh. Read the blog title again. The subject is easily discerned. Besides, both intelligence and will are conceptually classified - in this application - as emergent properties [qualitative] of an emergent property [quantitative]. They are NOT something else entirely.

I, and the vast majority of neuroscientists, accept that our mental lives supervene on the activities of our brains. That does not mean that we believe that neurons are magically influenced by mental states to behave differently from the way they would otherwise according to low-order physical laws.

Appeal to your own authority isn't all that impressive (though it does make me glad for Cytowic and other open-minded researchers). You don't believe in emergence as supervenience, don't believe supervenience is downward causation* per its controlling agency over the collective substrate, and you don't believe that any of it reduces to nonlinear dynamics. Noted.

But your beliefs don't settle the matter, and they don't convince me. Again, if it makes you uncomfortable to discuss the topic, don't. For those who are interested, I have given a number of links to material that explains pretty well the philosophical concepts and scientific applications. Complaints about those expositions should be directed to those sources.

* Donald T. Campbell, "Downward Causation in Hierarchically Organised Biological Systems," in F.J. Ayala and T. Dobzhansky, eds., Studies in the Philosophy of Biology: Reduction and Related Problems (Berkeley and Los Angeles: University of California Press, 1974).

* William Jaworski, "Mental Causation from the Top Down," in Erkenntnis, Volume 65, Number 2, September 2006 (Springer).

Biologists do not invoke strong emergence to explain life. The laws of physics are followed inside and outside of living organisms. Therefore weak emergence is quite sufficient.

Hmmm.

Explain why proteins fold in the precise characteristic shape they do. Why are humans bilaterally symmetric (for the most part)? Why do acquired characteristics tend to become inherited characteristics?

None of these have been explained reductionistically. It is absolutely premature to proclaim that "weak emergence is quite sufficient" — since it hasn't been sufficient to explain epigenesis, developmental regulation, protein folding, and a host of other holistic phenomena.