Almost one year ago, in April 2007, Matthew C submitted the following suggestion for an Overcoming Bias topic:
"How and why the current reigning philosophical hegemon (reductionistic materialism) is obviously correct [...], while the reigning philosophical viewpoints of all past societies and civilizations are obviously suspect—"
I remember this, because I looked at the request and deemed it legitimate, but I knew I couldn't do that topic until I'd started on the Mind Projection Fallacy sequence, which wouldn't be for a while...
But now it's time to begin addressing this question. And while I haven't yet come to the "materialism" issue, we can now start on "reductionism".
First, let it be said that I do indeed hold that "reductionism", according to the meaning I will give for that word, is obviously correct; and to perdition with any past civilizations that disagreed.
This seems like a strong statement, at least the first part of it. General Relativity seems well-supported, yet who knows but that some future physicist may overturn it?
On the other hand, we are never going back to Newtonian mechanics. The ratchet of science turns, but it does not turn in reverse. There are cases in scientific history where a theory suffered a wound or two, and then bounced back; but when a theory takes as many arrows through the chest as Newtonian mechanics, it stays dead.
"To hell with what past civilizations thought" seems safe enough, when past civilizations believed in something that has been falsified to the trash heap of history.
And reductionism is not so much a positive hypothesis, as the absence of belief—in particular, disbelief in a form of the Mind Projection Fallacy.
I once met a fellow who claimed that he had experience as a Navy gunner, and he said, "When you fire artillery shells, you've got to compute the trajectories using Newtonian mechanics. If you compute the trajectories using relativity, you'll get the wrong answer."
And I, and another person who was present, said flatly, "No." I added, "You might not be able to compute the trajectories fast enough to get the answers in time—maybe that's what you mean? But the relativistic answer will always be more accurate than the Newtonian one."
"No," he said, "I mean that relativity will give you the wrong answer, because things moving at the speed of artillery shells are governed by Newtonian mechanics, not relativity."
"If that were really true," I replied, "you could publish it in a physics journal and collect your Nobel Prize."
Standard physics uses the same fundamental theory to describe the flight of a Boeing 747 airplane, and collisions in the Relativistic Heavy Ion Collider. Nuclei and airplanes alike, according to our understanding, are obeying special relativity, quantum mechanics, and chromodynamics.
But we use entirely different models to understand the aerodynamics of a 747 and a collision between gold nuclei in the RHIC. A computer modeling the aerodynamics of a 747 may not contain a single token, a single bit of RAM, that represents a quark.
So is the 747 made of something other than quarks? No, you're just modeling it with representational elements that do not have a one-to-one correspondence with the quarks of the 747. The map is not the territory.
Why not model the 747 with a chromodynamic representation? Because then it would take a gazillion years to get any answers out of the model. Also we could not store the model on all the memory on all the computers in the world, as of 2008.
As the saying goes, "The map is not the territory, but you can't fold up the territory and put it in your glove compartment." Sometimes you need a smaller map to fit in a more cramped glove compartment—but this does not change the territory. The scale of a map is not a fact about the territory, it's a fact about the map.
If it were possible to build and run a chromodynamic model of the 747, it would yield accurate predictions. Better predictions than the aerodynamic model, in fact.
To build a fully accurate model of the 747, it is not necessary, in principle, for the model to contain explicit descriptions of things like airflow and lift. There does not have to be a single token, a single bit of RAM, that corresponds to the position of the wings. It is possible, in principle, to build an accurate model of the 747 that makes no mention of anything except elementary particle fields and fundamental forces.
"What?" cries the antireductionist. "Are you telling me the 747 doesn't really have wings? I can see the wings right there!"
The notion here is a subtle one. It's not just the notion that an object can have different descriptions at different levels.
It's the notion that "having different descriptions at different levels" is itself something you say that belongs in the realm of Talking About Maps, not the realm of Talking About Territory.
It's not that the airplane itself, the laws of physics themselves, use different descriptions at different levels—as yonder artillery gunner thought. Rather we, for our convenience, use different simplified models at different levels.
If you looked at the ultimate chromodynamic model, the one that contained only elementary particle fields and fundamental forces, that model would contain all the facts about airflow and lift and wing positions—but these facts would be implicit, rather than explicit.
You, looking at the model, and thinking about the model, would be able to figure out where the wings were. Having figured it out, there would be an explicit representation in your mind of the wing position—an explicit computational object, there in your neural RAM. In your mind.
You might, indeed, deduce all sorts of explicit descriptions of the airplane, at various levels, and even explicit rules for how your models at different levels interacted with each other to produce combined predictions—
And the way that algorithm feels from inside, is that the airplane would seem to be made up of many levels at once, interacting with each other.
The way a belief feels from inside, is that you seem to be looking straight at reality. When it actually seems that you're looking at a belief, as such, you are really experiencing a belief about belief.
So when your mind simultaneously believes explicit descriptions of many different levels, and believes explicit rules for transiting between levels, as part of an efficient combined model, it feels like you are seeing a system that is made of different level descriptions and their rules for interaction.
But this is just the brain trying to be efficiently compress an object that it cannot remotely begin to model on a fundamental level. The airplane is too large. Even a hydrogen atom would be too large. Quark-to-quark interactions are insanely intractable. You can't handle the truth.
But the way physics really works, as far as we can tell, is that there is only the most basic level—the elementary particle fields and fundamental forces. You can't handle the raw truth, but reality can handle it without the slightest simplification. (I wish I knew where Reality got its computing power.)
The laws of physics do not contain distinct additional causal entities that correspond to lift or airplane wings, the way that the mind of an engineer contains distinct additional cognitive entities that correspond to lift or airplane wings.
This, as I see it, is the thesis of reductionism. Reductionism is not a positive belief, but rather, a disbelief that the higher levels of simplified multilevel models are out there in the territory. Understanding this on a gut level dissolves the question of "How can you say the airplane doesn't really have wings, when I can see the wings right there?" The critical words are really and see.
Why do we distinguish “map” and “territory”? Because they correspond to “beliefs” and “reality”, and we have learnt elsewhere in the Sequences that
Let’s apply that test. It isn’t only predictions that apply at different levels, so do the results. We can have right or wrong models at quark level, atom level, crystal level, and engineering component level. At each level, the fact that one model is right and another wrong is a fact about reality: it is Talking about Territory. When we say a 747 wing is really there, we mean that (for example) visualising it as a saucepan will result in expectations that the results will not fulfil in the way that they will when visualising it as a wing. Indeed, we can have many different models of the wing, all equally correct - since they all result in predictions that conform to the same observations. The choice of correct model is what is in our head. The fact that it has to be (equivalent to) a model of a wing to be correct is in the Territory. In short, when Talking about Territory we can describe things at as many levels (of aggregation) as yield descriptions that can be tested against observation.
What exactly is meant by “levels” here? The Naval Gunner is arguing about levels of approximation. The discussion of Boeing 747 wings is an argument about levels of aggregation. They are not the same thing. Treating the forces on an aircraft wing at the aggregate level is leaving out internal details that per se do not affect the result. There will certainly be approximations involved in practice, of course, but they don’t stem from the actual process of aggregation, which is essentially a matter of combining all the relevant force equations algebraically, eliminating internal forces, before solving them; rather than combining the calculated forces numerically.
The way that reality works, as far as we can tell, is that there are basic ingredients, with their properties, which in any given system at any given instant exist in a particular configuration. Now reality is not just the ingredients but also the configuration - a wrong model of the configuration will give wrong predictions just as a wrong model of the ingredients will. The possible configurations include known stable structures. These structures are likewise real because any model of a configuration which cannot be transformed into a model which includes the identified structure in question is in conflict with reality. Physics is I understand it comprises (a) laws that are common to different configurations of the ingredients, and (b) laws that are common to different configurations of the known stable structures. Physicalism implies the belief that laws (b) are always consistent with laws (a) when both are sufficiently accurate.
True but the key word here is “additional”. Newton’s laws were undoubtedly laws of physics, and in my school physics lessons were expressed in terms of forces on bodies, rather than on their constituent particles. The laws for forces on constituent particles were then derived from Newton’s laws by a thought experiment in which a body is divided up. In higher education today the reverse process is the norm, but reality is indifferent to which equivalent formulation we use: both give identical predictions.[Original wording edited]
General Relativity contains the additional causal entity known as space-time curvature, which is an aggregate effect of all the massive particles in the universe given their configuration so is not a natural fit in the Procrustean bed of reductionism. [Postscript] Interestingly, I've read that Newton was never happy with his idea of gravitation as a force of attraction between two things because it implied a property shared between the two things concerned and therefore being intrinsic to neither - but failed to find a better formulation.
Indeed, but when you see a wing it is not just in the mind, it is also evidence of how reality is configured. It is the result of the experiment you perform by looking.
What the gunner really thought is pure speculation of course, but this assumption by EY raises an important point about meta-models.
In thought experiments the outcome is determined by the applicable universal laws – that’s meta-model (A). In any real-world case you need a model of the application as well as models of universal laws. That’s meta-model (B). An actual artillery shell will be affected by things like air resistance, so the greater accuracy of Einstein’s laws in textbook cases is no guarantee of it giving more accurate results in this case. EY obviously knew this, but his meta-model excluded it from consideration here. Treating the actual application as a case governed only by Newton’s or Einstein’s laws is itself a case of “Mind Projection Fallacy” – projecting meta-model (A) onto a real-world application. So it’s not a case of the gunner mistaking a model for reality, but of mistaking the criteria for choosing between one imperfect model and another. I imagine gunners are generally practical men, and in the field of the applied sciences it is very common for competing theories to have their own fields of application where they are more accurate than the alternatives – so although he was clearly misinformed, at least his meta-model was the right one.
[Postscript] An arguable version of reductionism is the belief that laws about the ingredients of reality are in some sense "more fundamental" than laws about stable structures of the ingredients. This cannot be an empirical truth, since both laws give the same predictions where they overlap so cannot be empirically distinguished. Neither is any logical contradiction implied by its negation. It can only be a metaphysical truth, whatever that is. Doesn't it come down to believing Einstein's essentialist concept of science against Bohr's instrumentalist version? That science doesn't just describe, but also tells? So pick Bohr as an opponent if you must, not some anonymous gunner.