Determined, page 18
What inspired me to include this example? A man named Bhupendra Madhiwalla, then age eighty-two, living in Mumbai, India, did that experiment with a toenail of his, repeatedly photographed the regrowth process and then emailed pictures to me from out of the blue. Which made me immensely happy.
Now the awesome final example. As a tautology, studying the function of neurons in the brain tells you about the function of neurons in the brain. But sometimes more detailed information can be found by growing neurons in petri dishes. These are typically two-dimensional “monolayer” cultures, where a slurry of individual neurons is plated down randomly, then begin to connect with each other as a carpet. However, some fancy techniques make it possible to grow three-dimensional cultures, where the slurry of a few thousand neurons is suspended in a solution. And these neurons, each floating on its own, find and connect up with each other, forming clumps of brain “organoids.” And after months, these organoids, barely large enough to be visible without a microscope, self-organize into brain structures. A slurry of human cortical neurons starts making radiating scaffolding,[*] constructing a primitive cortex with the beginnings of separate layers, even the beginnings of cerebrospinal fluid. And these organoids eventually produce synchronized brain waves that mature similarly to the way they do in fetal and neonatal brains. A random bunch of neurons, perfect strangers floating in a beaker, spontaneously build themselves into the starts of our brains.[*] Self-organized Versailles is child’s play in comparison.[36]
What has this tour shown us? (A) From molecules to populations of organisms, biological systems generate complexity and optimization that match what computer scientists, mathematicians, and urban planners achieve (and where roboticists explicitly borrow swarm intelligence strategies of insects[37]). (B) These adaptive systems emerge from simple constituent parts having simple local interactions, all without centralized authority, overt comparisons followed by decision-making, a blueprint, or a blueprint maker.[*] (C) These systems have characteristics that exist only at the emergent level—a single neuron cannot have traits related to circuitry—and whose behavior can be predicted without having to resort to reductive knowledge about the component parts. (D) Not only does this explain emergent complexity in our brains, but our nervous systems use some of the same tricks used by the likes of individual proteins, ant colonies, and slime molds. All without magic.
Well, that’s nice. Where does free will come into this?
8
Does Your Free Will Just Emerge?
First, What All of Us Can Agree On
So emergence is about reductive piles of bricks producing spectacular emergent states, ones that can be thoroughly unpredictable or that can be predicted based on properties that exist only at the emergent level. Reassuringly, no one thinks that free will lurks in the neuronal equivalent of individual bricks (well, almost no one; wait for the next chapter). This is nicely summarized by philosopher Christian List of Ludwig Maximilian University in Munich: “If we look at the world solely through the lens of fundamental physics or even that of neuroscience, we may not find agency, choice, and mental causation,” and people rejecting free will “make the mistake of looking for free will at the wrong level, namely the physical or neurobiological one—a level at which it cannot be found.” Robert Kane states the same: “We think we have to become originators at the micro-level [to explain free will] . . . and we realize, of course, that we cannot do that. But we do not have to. It is the wrong place to look. We do not have to micro-manage our individual neurons one by one.”[1]
So these free-will believers accept that an individual neuron cannot defy the physical universe and have free will. But a bunch of them can; to quote List, “free will and its prerequisites are emergent, higher-level phenomena.”[2]
Thus, a lot of people have linked emergence and free will; I will not consider most of them because, to be frank, I can’t understand what they’re suggesting, and to be franker, I don’t think the lack of comprehension is entirely my fault. As for those who have more accessibly explored the idea that free will is emergent, I think there are broadly three different ways in which they go wrong.
Problem #1: Chaotic Missteps Redux
We know the drill. Compatibilists and free-will-skeptic incompatibilists agree that the world is deterministic but disagree about whether free will can coexist with that. But if the world is indeterministic, you’ve cut the legs out from under free-will skeptics. The chaos chapter showed how you get there by confusing the unpredictability of chaotic systems with indeterminism. You can see how folks drive off a cliff with the same mistake about the unpredictability of many instances of emergent complexity.
A great example of this is found in the work of List, a philosophy heavyweight who made a big splash with his 2019 book, Why Free Will Is Real. As noted, List readily recognizes that individual neurons work in a deterministic way, while holding out for higher-level, emergent free will. In this view, “the world may be deterministic at some levels and indeterministic at others.”[3]
List emphasizes unique evolution, a defining feature of deterministic systems, where any given starting state can produce only one given outcome. Same starting state, run it over and over, and not only should you get one mature outcome each time, but it better be the same one. List then ostensibly proves the existence of emergent indeterminism with a model that appears in various forms in a number of his publications:
The top panel represents a reductive, fine-grain scenario where (progressing from left to right) five similar starting states each produce five distinct outcomes. We then turn to the bottom panel, which is a state that List says displays emergent indeterminism. How does he get there? The bottom panel “shows the same system at a higher level of description, obtained by coarse-graining the state space,” making use of “the usual rounding convention.” And when you do that, those five different starting states become the same, and that singular starting state can produce five completely different paths, proving that it is indeterministic and unpredictable.[4]
Er, maybe not. Sure, a system that is deterministic at the micro level can be indeterministic at the macro in this way, but only if you’re allowed to decide that five different (though similar) starting states are all actually the same, merging them into a single higher-order simulation. This is the last chapter all over again—when you’re Edward Lorenz, come back from lunch and coarse-grain your computer program, decide that the morning’s parameters can be rounded off with the usual rounding convention, and you’re bit in the rear by a butterfly. Two things that are similar are not identical, and you can’t decide that they are simply because that represents the conventions of thinking.
Reflecting my biological roots, here’s a demonstration of the same point:
Here are six different molecules, all with similar structures.[*] Now let’s coarse-grain ’em, decide that they are similar enough that we can consider them to be the same, by the usual scale of rounding convention, and therefore, they can be used interchangeably when we inject one of them into someone’s body and see what happens. And if there isn’t always the same exact effect, yeah, you’ve supposedly just demonstrated emergent indeterminism.
But they’re not all the same. Consider the middle and bottom structures in the first column. Majorly similar—just try remembering their structural differences for a final exam. But if you coarse-grain them into being the same, rather than just very similar, things are going to get really messy—because the top molecule of the two is a type of estrogen, and the bottom is testosterone. Ignore sensitive dependence on initial conditions, decide the two molecules are the same by whatever you’ve deemed the usual conventional rounding, and sometimes you get someone with a vagina, sometimes a penis, sometimes sort of both. Supposedly proving emergent indeterminism.[*]
It’s the last chapter redux; unpredictable is not the same thing as indeterministic. Disperse armies of ants at ten feeding spots, and you can’t predict just how close (and by what route) they are going to get to the solution to the traveling-salesman problem out of the 360,000+ possibilities. Instead, you’ll have to simulate what happens to their cellular automaton step by step. Do it all again, same ants at the same starting points but with one of those ten feeding spots in a slightly different location, and you might get a different (but still remarkably close) approximation of the traveling-salesman solution. Do it repeatedly, each time with one of the feeding stations moved slightly, and you’re likely to get an array of great solutions. Small differences in starting states can generate very different outcomes. But an identical starting state can’t do that and supposedly prove indeterminacy.
Problem #2: Orphans Running Wild
So much for the idea that in emergent systems the same starting state can give rise to multiple outcomes. The next mistake is a broader one—the idea that emergence means the reductive bricks that you start with can give rise to emergent states that can then do whatever the hell they want.
This has been stated in a variety of ways, where terms like brain, cause and effect, or materialism stand in for the reductive level, while terms like mental states, a person, or I imply the big, emergent end product. According to philosopher Walter Glannon, “although the brain generates and sustains our mental states, it does not determine them, and this leaves enough room for individuals to ‘will themselves to be’ through their choices and actions.” “Persons,” he concludes, “are constituted by but not identical to their brains.” Neuroscientist Michael Shadlen writes of emergent states having a special status as a “consequence of their emergence as entities orphaned from the chain of cause and effect that led to their implementation in neural machinery” (italics mine). Adina Roskies relatedly writes, “Macrolevel explanations are independent of the truth of determinism. These same arguments suffice to explain why an agent still makes a choice in a deterministic world, and why he or she is responsible for it.”[5]
This raises an important dichotomy. Philosophers with this interest discuss “weak emergence,” which is where no matter how cool, ornate, unexpected, and adaptive an emergent state is, it is still constrained by what its reductive bricks can and can’t do. This is contrasted with “strong emergence,” where the emergent state that emerges from the micro can no longer be deduced from it, even in chaoticism’s sense of a stepwise manner.
The well-respected philosopher Mark Bedau, of Reed College, considers the strong emergence that can do as it pleases with happy-go-lucky free will to be close to theoretically impossible.[*] Strong emergence claims “heighten the traditional worry that emergence entails illegitimately getting something from nothing,” which is “uncomfortably like magic.”[*] The influential philosopher David Chalmers of New York University weighs in as well, considering that the only thing that comes close to qualifying as a case of strong emergence is consciousness; likewise with another major contributor to this field, Johns Hopkins physicist Sean Carroll, who thinks that while consciousness is the only real reason to be interested in strong emergence, it’s sure not a case of it.
With a limited role, if any, for strong emergence (and thus for its being the root of free will), we are left with weak emergence, which, in Bedau’s words, “is no universal solvent.” You can be out of your mind but not out of your brain; no matter how emergently cool, ant colonies are still made of ants that are constrained by whatever individual ants can or can’t do, and brains are still made of brain cells that function like brain cells.[6]
Unless you resort to one last trick to pull free will from emergence.
Problem #3: Defying Gravity
The place where a final mistake creeps in is the idea that an emergent state can reach down and change the fundamental nature of the bricks comprising it.
We all know that an alteration at the brick level can change the emergent end product. If you’re injected with many copies of a molecule that activates six of the fourteen subtypes of serotonin receptors,[*] your macro level is likely to include perceiving vivid images that other people don’t, plus maybe even some religious transcendence. Dramatically drop the number of glucose molecules in someone’s bloodstream, and their resulting macro level will have trouble remembering whether Grover Cleveland was president before or after Benjamin Harrison.[*] Even if consciousness qualifies as the closest thing to true strong emergence, induce unconsciousness by infusing a molecule like phenobarbital, and you’ll have shown that it isn’t remotely free from its building blocks.
Good, we all agree that altering the little can change the emergent big. And the reverse certainly holds true. Sit here and press button A or B, and which motor neurons tell your arm muscles to shift this way or that will be manipulated by the emergent macrophenomenon called aesthetics, if you’re asked which painting you prefer, the one of a Renaissance woman with a half smile or the one of Campbell’s soup cans. Or press the button indicating which of two people you deem more likely to be destined for hell, or whether 1946’s Call Me Mister or 1950’s Call Me Madam is the more obscure musical.
A 2005 study concerning social conformity shows a particularly stark, fascinating version of the emergent level manipulating the reductive business of individual neurons. Sit a subject down and show them three parallel lines, one clearly shorter than the other two. Which is shorter? Obviously that one. But put them in a group where everyone else (secretly working on the experiment) says the longest line is actually the shortest—depending on the context, a shocking percentage of people will eventually say, yeah, that long line is the shortest one. This conformity comes in two types. In the first, go-along-to-get-along public conformity, you know which line is shortest but join in with everyone else to be agreeable. In this circumstance, there is activation of the amygdala, reflecting the anxiety driving you to go along with what you know is the wrong answer. The second type is “private conformity,” where you drink the Kool-Aid and truly believe that somehow, weirdly, you got it all wrong with those lines and everyone else really was correct. And in this case, there is also activation of the hippocampus, with its central role in learning and memory—conformity trying to rewrite the history of what you saw. But even more interesting, there’s activation of the visual cortex—“Hey, you neurons over there, the line you foolishly thought was longer at first is actually shorter. Can’t you just see the truth now?”[*],[7]
Think about this. When is a neuron in the visual cortex supposed to activate? Just to wallow in minutiae that can be ignored, when a photon of light is absorbed by rhodopsin in disc membranes within a retinal photoreceptive cell, causing the shape of the protein to change, changing transmembrane ion currents, thus decreasing the release of the neurotransmitter glutamate, which gets the next neuron in line involved, starting a sequence culminating in that visual cortical neuron having an action potential. One big micro-level blowout of reductionism.
And what’s happening instead during private conformity? That same Mr. Machine little neuron in the visual cortex activates because of the macro-level emergent state that we’d call an urge toward fitting in, a state built out of the neurobiological manifestations of the likes of cultural values, a desire to seem likable, adolescent acne having left scars of low self-esteem, and so on.[*],[8]
So some emergent states have downward causality, which is to say that they can alter reductive function and convince a neuron that long is short and war is peace.
The mistake is the belief that once an ant joins a thousand others in figuring out an optimal foraging path, downward causality causes it to suddenly gain the ability to speak French. Or that when an amoeba joins a slime mold colony that is solving a maze, it becomes a Zoroastrian. And that a single neuron, normally being subject to gravity, stops being so once it holds hands with all the other neurons producing some emergent phenomenon. That the building blocks work differently once they’re part of something emergent. It’s like believing that when you put lots of water molecules together, the resulting wetness causes each molecule to switch from being made of two hydrogens and one oxygen to two oxygens and one hydrogen. But the whole point of emergence, the basis of its amazingness, is that those idiotically simple little building blocks that only know a few rules about interacting with their immediate neighbors remain precisely as idiotically simple when their building-block collective is outperforming urban planners with business cards. Downward causation doesn’t cause individual building blocks to acquire complicated skills; instead, it determines the contexts in which the blocks are doing their idiotically simple things. Individual neurons don’t become causeless causes that defy gravity and help generate free will just because they’re interacting with lots of other neurons.
And the core belief among this style of emergent free-willers is that emergent states can in fact change how neurons work, and that free will depends on it. It is the assumption that emergent systems “have base elements that behave in novel ways when they operate as part of the higher-order system.” But no matter how unpredicted an emergent property in the brain might be, neurons are not freed of their histories once they join the complexity.[9]
This is another version of our earlier dichotomy. There’s weak downward causality, where something emergent like conformity can make a neuron fire the same way as it would in response to photons of light—the workings of this component part have not changed. And there’s strong downward causality, where it can. The consensus among most philosophers and neurobiologists thinking about this is that strong downward causality, should it exist, is irrelevant to this book’s focus. In a critique of this approach to discovering free will, psychologists Michael Mascolo of Merrimack College and Eeva Kallio of the University of Jyväskylä write, “While [emergent systems] are irreducible, they are not autonomous in the sense of having causal powers that override those of their constituents,” a point emphasized as well by Spanish philosopher Jesús Zamora Bonilla in his essay “Why Emergent Levels Will Not Save Free Will.” Or stated in biological terms by Mascolo and Kallio, “while the capacities for experience and meaning are emergent properties of biophysical systems, the capacity for behavioral regulation is not. The capacity for self-regulation is an already existing capacity of living systems.” There’s still gravity.[10]
