What made your characterization one of greedy reduction in my eyse was this

is best characterised as corresponding only to the lowest hierarchical level

Describe it at whatever level is most convenient. All levels are real to the extent that they model accurately.

The answer is in the rest of the sentence that you truncated!

It's not clear to me that's a complete response. It seems to be assuming that all instances of disagreement between reductionists and non-reductionists are linguistic, rather than causal. It looks to me like Bryan thinks that his qualia, like pain, are actually out there, and are not just very complicated ensembles of things reductionists like building models out of, like quarks and wavefunctions and so on.

It seems like attempting to resolve Bryan's disagreement with Robin about where Bryan's pain is located (B's "in my mind, not my brain" vs. R's "in your brain, which is also your mind") by claiming "well, of course Bryan's mental model of his pain doesn't exist in reality by definition" seems to be assuming definitions of 'mental model,' 'pain,' and 'reality' that I don't think Bryan would agree with.

Computers have hardware and information: that's a dualist model, and it has served very well as a model. At any given instant, the information is a state of the hardware, which requires a monist model, but it's information that is downloaded etc.

What do you mean when you say "but it's information that is downloaded"? That the monist model does not completely describe reality? That computer programming is easier with the dualist model than the monist model? That information lives in a nonphysical universe that communicates with the physical universe, such that only having the physical universe would be insufficient for computers to run?

As for the Naval Gunner, the point is that he would be right in other fields than fundamental physics. In weather forecasting long term forecasts using coarser models are actually more accurate than those using fine meshes, because of the chaotic behaviour at smaller scales.

I don't quite agree here. It's true that chaotic interactions and floating point multiplication errors mean that long-running fine-grained maps are less accurate than long-running coarse-grained maps, but it seems cleaner to consider that a fact about computer science, not meteorology.

Thanks for pointing to the more recent EY post, which I look forward to reading. No time tonight.

I would actually recommend Hands vs. Fingers first if you haven't read it yet. It's shorter and may be more directly relevant to your interests.

...much later... The thing that puzzles me about this post is that no attention is paid to context.

I had an operation last year to my right index finger. It was carried out by a hand surgeon. I used those terms because it was rather important which finger was operated on, and because the medical specialism relates to any part of the hand indifferently.

A trivial example, of course, but it illustrates the point, which applies also to much more complex issues, that the appropriate choice of "model level" (or other meta-model feature) to best represent the aspect of reality that matters depends on the context (and especially on the purpose). The difficulty begins, IMHO, when people insist on using the same model or meta-model whatever the context.

Most commenters on this post seem entirely wrapped up in the mind/brain question. That isn't the only question for rationalists to have a view about! They don't seem to be aware that arguments about the usefulness and limits of reductionism also continue in many other fields. The problem is probably that concepts like emergence are used in the mind-brain debate as an excuse for vitalism. But that is really a special case, just because minds are the things that are conducting this debate. In other fields emergence can be a useful concept. In other words I can claim that emergence is useful (in some senses anyway) without believing this has anything to do with consciousness.

Many different things can be deduced from this story, as previous comments have illustrated. The step that I question is "carries no information" = "magic". I prefer Karl Popper's account, in which [to paraphrase "Conjectures & Refutations" Chapter 1] "carries no predictive information" = "metaphysical" but "metaphysical" does not mean "unscientific". Rather, science involves two activities, hypothesis creation and hypothesis testing. It is the hypothesis testing that has to be exclusively empirical (confined to falsifiable hypotheses). There are no rules for arriving at new hypotheses according to Popper, only heuristics, and metaphysical arguments can often be a source of new insights that lead to new falsifiable hypotheses. I believe Imre Lakatos developed this distinction with his idea of "Research programmes" which cannot be falsified but get abandoned when they cease to be fruitful of falsifiable hypotheses. The commenters who have stressed that some of the student's wrong answers could be valuable first steps towards understanding fit into Popper's scheme. The question (which we can't answer) is whether the "password" status or the "first step" status was uppermost in their minds. To conclude, the posting is valuable in drawing attention to the disutility of password-type answers, but misleading in not also recognizing the role of first-step-type answers.

As for the Naval Gunner, the point is that he would be right in other fields than fundamental physics. In weather forecasting long term forecasts using coarser models are actually more accurate than those using fine meshes, because of the chaotic behaviour at smaller scales.

I don't quite agree here. It's true that chaotic interactions and floating point multiplication errors mean that long-running fine-grained maps are less accurate than long-running coarse-grained maps, but it seems cleaner to consider that a fact about computer science, not meteorology.

Thanks for pointing to the more recent EY post, which I look forward to reading. No time tonight.

I would actually recommend Hands vs. Fingers first if you haven't read it yet. It's shorter and may be more directly relevant to your interests.

From:

Sorry no time for a full answer, but roughly, yes, in a sense I do think that many of these disagreements turn out to be linguistic if you dig far enough.

and

Yes, and anything else that requires an intelligible account of what is going on. You start with a monist model and then you have to define something called or synonymous with information

it looks to me like you don't actually disagree with the definition of reductionism quoted in your post, and it seems like your primary concern is a combination of not being fair to critics of reductionism and a definition that doesn't distinguish between kinds of reductionism.

Those concerns are worth considering, but I think you're wrong on at least the first. The critics of reductionism that this post is targeted at are the Navy Gunners who think that GR and Newtonian Mechanics are different parts of the territory, not different maps that describe the territory at different levels of detail and completeness.

You mention someone calling the post attacking straw men, but I think that comment tree is worth rereading fully. Basically, this is what a worldview feels like from the inside- of course every sane person sees things this way, how could they not? But other people do sometimes have radically different worldviews, and sometimes they are radically confused about things.

Have you read EY's more recent post on reductionism (which may be clearer after reading the preceding posts)? I'm curious if that would help clarify where precisely you disagree.

Computers have hardware and information: that's a dualist model

Actually, it's a trialist model, or worse. Something or someone had to create and program the computers and push the start button.

The answer is in the rest of the sentence that you truncated!

It's not clear to me that's a complete response. It seems to be assuming that all instances of disagreement between reductionists and non-reductionists are linguistic, rather than causal. It looks to me like Bryan thinks that his qualia, like pain, are actually out there, and are not just very complicated ensembles of things reductionists like building models out of, like quarks and wavefunctions and so on.

It seems like attempting to resolve Bryan's disagreement with Robin about where Bryan's pain is located (B's "in my mind, not my brain" vs. R's "in your brain, which is also your mind") by claiming "well, of course Bryan's mental model of his pain doesn't exist in reality by definition" seems to be assuming definitions of 'mental model,' 'pain,' and 'reality' that I don't think Bryan would agree with.

Computers have hardware and information: that's a dualist model, and it has served very well as a model. At any given instant, the information is a state of the hardware, which requires a monist model, but it's information that is downloaded etc.

What do you mean when you say "but it's information that is downloaded"? That the monist model does not completely describe reality? That computer programming is easier with the dualist model than the monist model? That information lives in a nonphysical universe that communicates with the physical universe, such that only having the physical universe would be insufficient for computers to run?

Are you saying that you don't agree with my definition of reductionism?

Yes. Reductionism has nothing to do with how detailed our map is.