Kurzgesagt – In a Nutshell
Kurzgesagt – In a Nutshell
We thank following experts for their feedback:
Prof. Agustín Rayo
Massachusetts Institute of Technology
Dr. Philip Ball
Author and Science Writer
—Are you free? Free to choose what you do and make decisions? Or are you an NPC, unable to decide anything for yourself? You feel that you have control over your life, or at least what you’ll have for breakfast. But this may be an illusion. Physics actually may force you to go through life as if on rails, with no free will at all.
These sentences summarize the classical problem of free will: We all FEEL that we make our own decisions in our life, but if we are all made of particles that follow the fixed laws of physics, that intuition is hard to justify.
#Stanford Encyclopedia of Philosophy: “Free Will” (retrieved 2024)
https://plato.stanford.edu/entries/freewill/
Quote: “The term “free will” has emerged over the past two millennia as the canonical designator for a significant kind of control over one’s actions. Questions concerning the nature and existence of this kind of control (e.g., does it require and do we have the freedom to do otherwise or the power of self-determination?), and what its true significance is (is it necessary for moral responsibility or human dignity?) have been taken up in every period of Western philosophy and by many of the most important philosophical figures, such as Plato, Aristotle, Augustine, Aquinas, Descartes, and Kant.”
—Free will is your ability to decide by yourself what you do. It means that the future is an open arena that you can shape with your actions. It’s at the core of human relationships – it means you are responsible for your actions, which is the basis of our moral and legal systems.
This is an informal, intuitive definition of free will, which however emphasizes the main idea shared by all the more formal definitions. "The ability to decide by yourself" means that we can exert some degree of CONTROL over the world around us via our actions, which is at the core of all definitions of free will:
#Stanford Encyclopedia of Philosophy: “Free Will” (retrieved 2024)
https://plato.stanford.edu/entries/freewill/
Quote: “As should be clear from this short discussion of the history of the idea of free will, free will has traditionally been conceived of as a kind of power to control one’s choices and actions. When an agent exercises free will over her choices and actions, her choices and actions are up to her. But up to her in what sense? As should be clear from our historical survey, two common (and compatible) answers are: (i) up to her in the sense that she is able to choose otherwise, or at minimum that she is able not to choose or act as she does, and (ii) up to her in the sense that she is the source of her action. However, there is widespread controversy both over whether each of these conditions is required for free will and if so, how to understand the kind or sense of freedom to do otherwise or sourcehood that is required. ”
However, one of the main problems when discussing free will in detail is the precise definition of the concept itself. Free will has been defined as the freedom to do otherwise; as the possibility of actively choose between different futures; by means of its role on moral responsibility; via the relevant origin (cause, or "sourcehood" in philosophical jargon) of our actions; or via its (in)compatibility with the deterministic laws of physics. We won't go into these differences in this video, but a brief summaries of some of them can be found here:
https://www.britannica.com/topic/free-will
https://www.britannica.com/topic/free-will-and-moral-responsibility
—There are too many dimensions for one short video – moral, psychological, biological, so we’ll focus on the most essential part:
There are many interesting aspects of free will we will leave undiscussed in this video.
One of them is the moral aspect, and in particular the discussion on the relationship between free will and moral responsibility, with its important ramifications for law and justice. It includes, for example, the problem of whether or not free will, and which aspect of it exactly, is necessary for moral responsibility.
#Stanford Encyclopedia of Philosophy: “Free Will: Freedom to Do Otherwise vs. Sourcehood Accounts” (retrieved 2024)
https://plato.stanford.edu/entries/freewill/#FreeDoOtheVsSourAcco
Quote: “While Frankfurt (1971) took this to show that moral responsibility and free will come apart—free will requires the ability to do otherwise but moral responsibility does not—if we define ‘free will’ as ‘the strongest control condition required for moral responsibility’ (cf. Wolf 1990, 3–4; Fischer 1994, 3; Mele 2006, 17), then if Frankfurt-style cases show that moral responsibility does not require the ability to do otherwise, then they also show that free will does not require the ability to do otherwise. Let us consider this challenge in more detail.
Here is a representative Frankfurt-style case:
Imagine, if you will, that Black is a quite nifty (and even generally nice) neurosurgeon. But in performing an operation on Jones to remove a brain tumor, Black inserts a mechanism into Jones’s brain which enables Black to monitor and control Jones’s activities. Jones, meanwhile, knows nothing of this. Black exercises this control through a sophisticated computer which he has programmed so that, among other things, it monitors Jones’s voting behavior. If Jones were to show any inclination to vote for Bush, then the computer, through the mechanism in Jones’s brain, intervenes to ensure that he actually decides to vote for Clinton and does so vote. But if Jones decides on his own to vote for Clinton, the computer does nothing but continue to monitor—without affecting—the goings-on in Jones’s head. (Fischer 2006, 38)
Fischer goes on to suppose that Jones “decides to vote for Clinton on his own”, without any interference from Black, and maintains that in such a case Jones is morally responsible for his decision.”
This idea was first presented in the following, more in-depth paper:
#Frankfurt, Harry G. (1969): “Alternate Possibilities and Moral Responsibility”, Journal of Philosophy, vol. 66, 23, 829-839
https://philarchive.org/rec/FRAAPA-8
The neurological aspect of free will is equally fascinating, for example in relation to Lbet’s experiments, series of famous experiments conducted in the 1980s by neuroscientist American Benjamin Libet which, at their time, many interpreted as having shown that our apparent autonomous decisions are actually taken by our brains before we are even aware of it.
#Libet, Benjamin et al. (1983): “Time of conscious intention to act in relation to onset of cerebral activity (readiness-potential). The unconscious initiation of a freely voluntary act”, Brain: A journal of neurology, vol. 106, 3, 623-42
Quote: “The recordable cerebral activity (readiness-potential, RP) that precedes a freely voluntary, fully endogenous motor act was directly compared with the reportable time (W) for appearance of the subjective experience of 'wanting' or intending to act. The onset of cerebral activity clearly preceded by at least several hundred milliseconds the reported time of conscious intention to act. This relationship held even for those series (with 'type II' RPs) in which subjects reported that all of the 40 self-initiated movements in the series appeared 'spontaneously' and capriciously. Data were obtained in at least 6 different experimental sessions with each of 5 subjects.
[...]
It is concluded that cerebral initiation of a spontaneous, freely voluntary act can begin unconsciously, that is, before there is any (at least recallable) subjective awareness that a 'decision' to act has already been initiated cerebrally. This introduces certain constraints on the potentiality for conscious initiation and control of voluntary acts.”
Since their publication these experiments have been subject of intense debate.
To keep this video focused, we will not address these angles, though we recognize their importance.
—Is free will even possible?
In this video, we will only consider whether or not free will is compatible with the laws of physics. We will assume that current scientific consensus about how physics and the brain work is true.
—Two main philosophical camps are fighting about this. No matter how we represent them, they will be upset about it – So we’ll use our own words.
When discussing free will in the context of physics, there are two main sides:
Incompatibilists, who think the laws of physics are incompatible with free will.
Compatibilists, who think there can be free will even if we have fixed laws of physics that determine the behavior of the particles we are made of.
#Stanford Encyclopedia of Philosophy: “Arguments for Incompatibilism” (retrieved 2024)
https://plato.stanford.edu/entries/incompatibilism-arguments/
Quote: “Determinism is a highly general claim about the universe: very roughly, that everything that happens, including everything you choose and do, is determined by facts about the past together with the laws. Determinism isn’t part of common sense, and it is not easy to take seriously the thought that it might, for all we know, be true. The incompatibilist believes that if determinism turned out to be true, our belief that we have free will would be false.”
#Stanford Encyclopedia of Philosophy: “Compatibilism” (retrieved 2024)
https://plato.stanford.edu/entries/compatibilism/
Quote: “Compatibilism offers a solution to the free will problem, which concerns a disputed incompatibility between free will and determinism. Compatibilism is the thesis that free will is compatible with determinism.”
There is another incompatibilist perspective we will not discuss in this video: libertarianism. Libertarianists think that the laws of physics as we know them are incompatible with free will, but, instead of concluding that free will does not exist, they conclude there is something wrong or incomplete about our current laws of physics.
#Stanford Encyclopedia of Philosophy: “Arguments for Incompatibilism” (retrieved 2024)
https://plato.stanford.edu/entries/incompatibilism-arguments/
Quote: “In the older literature, there were just two kinds of incompatibilists—hard determinists and libertarians. A hard determinist is an incompatibilist who believes that determinism is in fact true (or, perhaps, that it is close enough to being true so far as we are concerned, in the ways relevant to free will) and because of this we lack free will (Holbach 1770; Wegner 2003). A libertarian is an incompatibilist who believes that we in fact have free will and this entails that determinism is false, in the right kind of way (van Inwagen 1983). Traditionally, libertarians have believed that “the right kind of way” requires that agents have a special and mysterious causal power not had by anything else in nature: a godlike power to be an uncaused cause of changes in the world (Chisholm 1964). Libertarians who hold this view are committed, it seems, to the claim that free will is possible only at worlds that are at least partly lawless, and that our world is such a world (but see O’Connor 2000, Clarke 2003 and Steward 2012). But in the contemporary literature there are incompatibilists who avoid such risky metaphysical claims by arguing that free will is possible at worlds where some of our actions have indeterministic event causes (Kane 1996, 1999, 2008, 2011a; Ekstrom 2000; Balaguer 2010; Franklin 2018) or that free will is possible at worlds where some of our actions are uncaused (Ginet 1990).”
This is of course a fully legitimate position, but since it's largely outside the current views of established science we won't consider it in this video.
Regarding the incompatibilist (in the free-will-denying sense) and compatibilist positions, two recently published books with opposing views are Determined, by biologist Robert M. Sapolsky:
https://www.penguinrandomhouse.com/books/592344/determined-by-robert-m-sapolsky/
and Free Agents, by neuroscientist Kevin Mitchell:
https://press.princeton.edu/books/hardcover/9780691226231/free-agents
—Whatever “you” exactly are, it is somehow made up from your physical brain and body. And these are made of cells, which are made of proteins, which are made of atoms and particles like protons or electrons.
As emphasized above, in this video we'll be assuming the current scientific consensus. In particular, we'll assume that everything in the universe (including humans) is made of atoms and fundamental particles, and that no "immaterial" or otherwise unphysical effects exist.
In more technical terms, this implies two things:
We will assume the Mind/Brain identity theory, which is the shared consensus among practicing neuroscientists.
#Stanford Encyclopedia of Philosophy: “The Mind/Brain Identity Theory” (retrieved 2024)
https://plato.stanford.edu/entries/mind-identity/
Quote: “The identity theory of mind holds that states and processes of the mind are identical to states and processes of the brain. Strictly speaking, it need not hold that the mind is identical to the brain. Idiomatically we do use ‘She has a good mind’ and ‘She has a good brain’ interchangeably but we would hardly say ‘Her mind weighs fifty ounces’. Here I take identifying mind and brain as being a matter of identifying processes and perhaps states of the mind and brain. Consider an experience of pain, or of seeing something, or of having a mental image. The identity theory of mind is to the effect that these experiences just are brain processes, not merely correlated with brain processes.”
That reductionism (the notion that all properties of a system can be explained by properties of its parts) is true, as explained here:
#Encyclopedia Britannica: “Unification and reduction” (retrieved 2024)
https://www.britannica.com/topic/philosophy-of-science/Unification-and-reduction
Quote: “There is a powerful intuitive argument for this attitude. If one considers the subject matter of the social sciences, for example, it seems that social phenomena are the product of people standing in complicated relations to each other and acting in complicated ways. These people, of course, are complex biological and psychological systems. Their psychological activity is grounded in the neural firings in their brains. Hence, people are intricate biological systems. The intricacies of biology are based on the choreography of molecular reactions within and between individual cells. Biology, then, is very complicated chemistry. Chemical reactions themselves involve the forming and breaking of bonds, and these are matters of microphysics. At the end of the day, therefore, all natural phenomena, even those involving interactions between people, are no more than an exceptionally complicated series of transactions between the ultimate physical constituents of matter. A complete account of those ultimate constituents and their interactions would thus amount to a “theory of everything.”
and in the way defined by American physicist Philip W. Anderson in his influential 1972 paper "More is Different":
#Anderson, Philip W.(1972): “More is different”, Science, vol.177, 393-396
https://www.science.org/doi/abs/10.1126/science.177.4047.393
https://www.tkm.kit.edu/downloads/TKM1_2011_more_is_different_PWA.pdf
Quote: "The reductionist hypothesis may still be a topic for controversy among philosophers, but among the great majority of active scientists I think it is accepted without question. The workings of our minds and bodies, and of all the animate or inanimate matter of which we have any detailed knowledge, are assumed to be controlled by the same set of fundamental laws, which except under certain extreme conditions we feel we know pretty well."
—So fundamentally, you are a specific, quite lovely, dynamic pattern of particles. Particles have no will, no motivation, no freedom, but blindly follow the laws of physics. And we don’t know why, but most laws of physics are deterministic – which means that things happen the way they do because of the things that came before.
The laws of physics can be divided in two kinds: classical and quantum ( "classical" meaning everything which is non-quantum. As such, "classical physics" includes Einstein's theory of relativity, for example).
Classical physics is governed by differential equations. These kinds of equations have the mathematical property that, once you specify the initial conditions of a system, the future behavior of the system is fully determined. This has been explained for example in this 1968 extract by Nobel laureate Max Born:
#Born, Max (1969): “Physics in My Generation”, 78–83. Springer.
https://link.springer.com/chapter/10.1007/978-1-4615-7587-0_7
Quote: "The laws of classical mechanics, and through them the laws of classical physics as a whole, are so constructed that, if the variables in a closed system are given at some initial point of time, they can be calculated for any other instant."
That is, the future is fully determined by the present, which is why classical physics is said to be "deterministic".
A potential source of confusion are the so-called "chaotic" systems, like the weather. These are fully classical (i.e. non-quantum) systems, but which are typically unpredictable. However, this unpredictability is not fundamental: It just arises in practice because a small uncertainty in the initial conditions of the system (a butterfly in Japan flapping its wings or not, for example) can be grossly amplified and result in totally different results as time passes (a tornado or not in Brazil the next day, say). But if we had full knowledge of the initial state of a chaotic system, its future evolution could be perfectly determined as well – which is why a more accurate (and often used) term for this property is "deterministic chaos":
#Stanford Encyclopedia of Philosophy: “Chaos” (retrieved 2024)
https://plato.stanford.edu/entries/chaos/
Quote: ”To begin, chaos is typically understood as a mathematical property of a dynamical system. A dynamical system is a deterministic mathematical model, where time can be either a continuous or a discrete variable. Such models may be studied as mathematical objects or may be used to describe a target system (some kind of physical, biological or economic system, say). I will return to the question of using mathematical models to represent actual-world systems throughout this article.
For our purposes, we will consider a mathematical model to be deterministic if it exhibits unique evolution:
(Unique Evolution)
A given state of a model is always followed by the same history of state transitions.
A simple example of a dynamical system would be the equations describing the motion of a pendulum. The equations of a dynamical system are often referred to as dynamical or evolution equations describing the change in time of variables taken to adequately describe the target system (e.g., the velocity as a function of time for a pendulum). A complete specification of the initial state of such equations is referred to as the initial conditions for the model, while a characterization of the boundaries for the model domain are known as the boundary conditions. An example of a dynamical system with a boundary condition would be the equation modeling the flight of a rubber ball fired at a wall by a small cannon. The boundary condition might be that the wall absorbs no kinetic energy (energy of motion) so that the ball is reflected off the wall with no loss of energy. The initial conditions would be the position and velocity of the ball as it left the mouth of the cannon. The dynamical system would then describe the flight of the ball to and from the wall
Although some popularized discussions of chaos have claimed that it invalidates determinism, there is nothing inconsistent about systems having the property of unique evolution while exhibiting chaotic behavior (much of the confusion over determinism derives from equating determinism with predictability—see below). While it is true that apparent randomness can be generated if the state space (see below) one uses to analyze chaotic behavior is coarse-grained, this produces only an epistemic form of nondeterminism. The underlying equations are still fully deterministic. If there is a breakdown of determinism in chaotic systems, that can only occur if there is some kind of indeterminism introduced such that the property of unique evolution is rendered false (e.g., §4 below).”
So although important in the study of real physical systems, the existence of chaos doesn't affect the discussion about free will.
—Now imagine that if right after the Big Bang, a supersmart supercomputer looked at every single particle in the universe and noted all their properties. Just by applying the deterministic laws of physics, it should be able to predict what all the particles in existence would be doing until the end of time.
This is a formulation of the classic idea of Laplace’s Demon. It appeared first in:
#Laplace, Pierre Simon (1820): “A philosophical essay on probabilities”. Translation by Frederick Wilson Truscott and Frederik Lincoln Emory (1902). John Wiley & Sons.
https://www.gutenberg.org/files/58881/58881-h/58881-h.htm
Quote: “We ought then to regard the present state of the universe as the effect of its anterior state and as the cause of the one which is to follow. Given for one instant an intelligence which could comprehend all the forces by which nature is animated and the respective situation of the beings who compose it—an intelligence sufficiently vast to submit these data to analysis—it would embrace in the same formula the movements of the greatest bodies of the universe and those of the lightest atom; for it, nothing would be uncertain and the future, as the past, would be present to its eyes.”
—But if you are made of particles and it’s technically possible to calculate what particles will do forever, then you never decided anything. Your past, present and future were already predetermined and decided at the Big Bang. This would mean there is a kind of fate and you are not free to decide anything.
You may feel like you make decisions, but you are on autopilot. The motions of the particles that make up your brain cells that made you watch this video were decided 14 billion years ago. You are just in the room when it happens. You are only witnessing how the universe inside you unfolds in real time.
This is the core most famous problem faced by the idea of free will – in a fully deterministic universe there is no "freedom" left to actually decide anything, since all events are determined by the past. As a consequence, a really autonomous agent able to take free decisions (i.e. decisions that depend on what the agent wants or wishes, and were not already "taken" by the past state of the universe) would violate the laws of physics and hence can't exist.
#Encyclopedia Britannica: “Free will” (retrieved 2024)
https://www.britannica.com/topic/free-will
Quote: "The existence of free will is denied by some proponents of determinism, the thesis that every event in the universe is causally inevitable. Determinism entails that, in a situation in which people make a certain decision or perform a certain action, it is impossible that they could have made any other decision or performed any other action. In other words, it is never true that people could have decided or acted otherwise than they actually did. Philosophers and scientists who believe that determinism in this sense is incompatible with free will are known as “hard” determinists."
—But this can’t be true because of quantum mechanics, right? Quantum processes are intrinsically random, not deterministic, and can’t be predicted with total certainty. On the quantum pool table, balls can go randomly left or up or banana. Their behavior isn’t set by what came before but randomly decided in real time.
Apart from classical/deterministic laws, fundamental particles also follow the laws of quantum mechanics, which are well-known to be non-deterministic. The most we can predict in quantum mechanics are the probabilities of the different possible results of an experiment, but not the result itself with 100% accuracy:
#Encyclopedia Britannica: “Quantum mechanics” (retrieved 2024)
https://www.britannica.com/science/quantum-mechanics-physics
Quote: “A fundamental concept in quantum mechanics is that of randomness, or indeterminacy. In general, the theory predicts only the probability of a certain result. Consider the case of radioactivity. Imagine a box of atoms with identical nuclei that can undergo decay with the emission of an alpha particle. In a given time interval, a certain fraction will decay. The theory may tell precisely what that fraction will be, but it cannot predict which particular nuclei will decay. The theory asserts that, at the beginning of the time interval, all the nuclei are in an identical state and that the decay is a completely random process.”
Quantum randomness is fundamental, and therefore very different from the apparent randomness found in classical physics (like for example in chaotic systems), which is only due to a lack of knowledge of the initial conditions.
#Encyclopedia Britannica: “Quantum mechanics” (retrieved 2024)
https://www.britannica.com/science/quantum-mechanics-physics
Quote: “Even in classical physics, many processes appear random. For example, one says that, when a roulette wheel is spun, the ball will drop at random into one of the numbered compartments in the wheel. Based on this belief, the casino owner and the players give and accept identical odds against each number for each throw. However, the fact is that the winning number could be predicted if one noted the exact location of the wheel when the croupier released the ball, the initial speed of the wheel, and various other physical parameters. It is only ignorance of the initial conditions and the difficulty of doing the calculations that makes the outcome appear to be random. In quantum mechanics, on the other hand, the randomness is asserted to be absolutely fundamental. The theory says that, though one nucleus decayed and the other did not, they were previously in the identical state.”
—But for the no-free-will camp, this doesn’t affect their argument. They think that since quantum processes are random, they don’t allow you to make any decisions. Because if there is randomness for the things that fundamentally make up your brain and body, these random processes make the decisions for you. How?
The traditional and best-known argument against free will is the one based on the determinism of the physical laws and the implication that the future should therefore be fixed and fully "decided" already, leaving no place for an agent to make any choices. But that argument doesn't apply to quantum mechanics, since as explained above their laws are inherently random and therefore non-deterministic.
However, the fact that a process is random doesn't imply that a would-be agent has any control over it. In other words: fundamental randomness in the universe might imply that there is some kind of "freedom" (in the sense that the future might not be fully determined), but still leaves no room for the "will" of an agent to play any role in how events unfold:
#Encyclopedia Britannica: “Free will” (retrieved 2024)
https://www.britannica.com/topic/free-will
Quote: “Libertarianism is vulnerable to what is called the “intelligibility” objection, which points out that people can have no more control over a purely random action than they have over an action that is deterministically inevitable; in neither case does free will enter the picture. Hence, if human actions are indeterministic, free will does not exist.”
—We know that we can reduce everything that exists to its basic particles and the laws that guide them. While this makes physics feel like the only scientific discipline that actually matters, there is a problem: You can’t explain everything in our universe only from particles.
The point of view that is being summarized here was emphasized many years ago by the physicist and Nobel Prize winner Philip W. Anderson in his influential article "More is Different":
#Anderson, Philip W. (1972): “More is different”, Science, vol.177, 393-396
https://www.science.org/doi/abs/10.1126/science.177.4047.393
https://www.tkm.kit.edu/downloads/TKM1_2011_more_is_different_PWA.pdf
Quote: "The main fallacy in this kind of thinking is that the reductionist hypothesis does not by any means imply a "constructionist" one: The ability to reduce everything to simple fundamental laws does not imply the ability to start from those laws and reconstruct the universe. In fact, the more the elementary particle physicists tell us about the nature of the fundamental laws the less relevance they seem to have to the very real problems of the rest of science, much less to those of society. [...] The behavior of large and complex aggregates of elementary particles, it turns out, is not to be understood in terms of a simple extrapolation of the properties of a few particles. Instead, at each level of complexity entirely new properties appear, and the understanding of the new behaviors requires research which I think is as fundamental in its nature as any other."
It is important to notice that this point of view doesn't deny reductionism. Instead, it emphasizes that, although reductionism is still true, emergence makes it impossible to explain the properties of complex systems (like brains or humans) by looking only at the properties of the fundamental constituents of the universe.
—One key fact about reality that we can’t explain by looking just at electrons and quantum stuff is emergence. Emergence is when many small things together create new fundamental traits that didn’t exist before.
The concept of emergence is core to the study of complex systems. It is the general idea that interactions between parts of a system give that system properties that cannot be solely reduced to properties of the interacting parts.
#Stanford Encyclopedia of Philosophy: “Emergent Properties” (retrieved 2024)
https://plato.stanford.edu/entries/properties-emergent/
Quote: “The world appears to contain diverse kinds of objects and systems—planets, tornadoes, trees, ant colonies, and human persons, to name but a few—characterized by distinctive features and behaviors. This casual impression is deepened by the success of the special sciences, with their distinctive taxonomies and laws characterizing astronomical, meteorological, chemical, botanical, biological, and psychological processes, among others. But there’s a twist, for part of the success of the special sciences reflects an effective consensus that the features of the composed entities they treat do not “float free” of features and configurations of their components, but are rather in some way(s) dependent on them.
Consider, for example, a tornado. At any moment, a tornado depends for its existence on dust and debris, and ultimately on whatever micro-entities compose it; and its properties and behaviors likewise depend, one way or another, on the properties and interacting behaviors of its fundamental components. Yet the tornado’s identity does not depend on any specific composing micro-entity or configuration, and its features and behaviors appear to differ in kind from those of its most basic constituents, as is reflected in the fact that one can have a rather good understanding of how tornadoes work while being entirely ignorant of particle physics. The point generalizes to more complex and longer-lived entities, including plants and animals, economies and ecologies, and myriad other individuals and systems studied in the special sciences: such entities appear to depend in various important respects on their components, while nonetheless belonging to distinctive taxonomies and exhibiting autonomous properties and behaviors, as reflected in their governing special science laws.[...]
The general notion of emergence is meant to conjoin these twin characteristics of dependence and autonomy. It mediates between extreme forms of dualism, which reject the micro-dependence of some entities, and reductionism, which rejects macro-autonomy.”
There is no universally accepted rigorous definition of emergence:
#Kivelson, Sophia; Kivelson Steven A. (2016): “Defining emergence in physics”
https://www.nature.com/articles/npjquantmas20162t4
Quote: “The term emergent is used to evoke collective behaviour of a large number of microscopic constituents that is qualitatively different than the behaviours of the individual constituents. This usage is appealingly intuitive but problematically ill-defined: it is vague concerning what qualifies as a large number and what constitutes a qualitative difference.”
Though there have been numerous attempts at systematization, like here.
#Baas, Nils; Emmeche, Claus (1997): “On emergence and explanation”, Intellectica, 2, 25, 67-83
https://philpapers.org/rec/BAAOEA
https://www.santafe.edu/research/results/working-papers/on-emergence-and-explanation
Quote: “Emergence is a universal phenomenon that can be defined mathematically in a very general way. This is useful for the study of scientifically legitimate explanations of complex systems, here defined as hyperstructures. A requirement is that the observation mechanisms are considered within the general framework. Two notions of emergence are defined, and specific examples of these are discussed.”
#Fuentes, Miguel A. (2014): “Complexity and the Emergence of Physical Properties”, Entropy, 16, 8, 4489-4496
https://www.mdpi.com/1099-4300/16/8/4489
Quote: “Using the effective complexity measure, proposed by M. Gell-Mann and S. Lloyd, we give a quantitative definition of an emergent property. We use several previous results and properties of this particular information measure closely related to the random features of the entity and its regularities.”
—A drop of water is just a sextillion H2O molecules.
The weight of a drop of water can vary, but here we will take it to be half a gram. Since the molecular weight of water is 18.015 g/mol, we can calculate how many moles there is in a drop:
(0.5 g) / (18.015 g/mol) = 0.0278 mol
#PubChem: “Water” (retrieved 2024)
https://pubchem.ncbi.nlm.nih.gov/compound/962
Then, we calculate the number of molecules using Avogadro’s number:
0.0278 mol × (6.022·1023 molecules/mol) = 1.67·1022 molecules
#Particle data group (2023): “Physical Constants”
https://pdg.lbl.gov/2023/reviews/rpp2023-rev-phys-constants.pdf
Which is around a sextillion (or 1021) molecules.
—If you take a glass of water and spill it on your pants, they get wet. But what is… wetness? H2O molecules are not wet. But your pants are definitely wet now. Many small things together just created something new that doesn't exist at the level of the individual molecules.
Many properties, such as superconductivity, ferromagnetism and turbulence in physics; or swarming and segregation in biology and the social sciences, can only be defined for large ensembles and have no meaning at the individual level. A more detailed review of such properties can be found here:
#Artime, Oriol; De Domenico, Manlio (2022): “From the origin of life to pandemics: emergent phenomena in complex systems” Philosophical Transactions of the Royal Society, vol.380, 20200410
https://royalsocietypublishing.org/doi/10.1098/rsta.2020.0410#d1e1438
Quote: “However, there are properties that cannot be defined at the level of a single unit, whether a particle, a cell or an individual: such properties are meaningful only at some scale larger than the one defining a single unit. When this is the case, the corresponding phenomena are usually referred to as emergent: emergence is considered a fundamental feature of complex adaptive matter, transcending the traditional frontiers of theoretical physics and becoming a landmark in a broad spectrum of disciplines, from biology to neuroscience, from system ecology to economics. In the following, we will briefly review a broad class of complex systems across a variety of disciplines, starting from the quantum realm and then moving to non-quantum systems, including physics, biology, ecology, social and urban sciences.”
In more familiar terms, though a water molecule is not “wet”, many of them make a puddle, which is wet. In the same way, a single car is not a traffic jam, nor a single grain of sand a dune, but enough cars and grains of sand make traffic jams and dunes, which have distinct properties from those of cars and grains of sand.
—Emergence occurs at all levels of reality, and reality seems to be organized in layers: atoms, molecules, cells, tissues, organs, you, society. Put many things in one layer together and they’ll create the next layer up. Every time they do, entirely new properties emerge.
Emergence appears in many seemingly unrelated fields, from materials science to ecology. .
#Fuentes, Miguel A. (2014): “Complexity and the Emergence of Physical Properties”, Entropy, 16, 8, 4489-4496
https://www.mdpi.com/1099-4300/16/8/4489
Quote: “In general, nowadays, emergence is broadly used to assign certain properties to features we observe in nature that have certain dependence on more basic phenomena (and/or elements), but are in some way independent from them and ultimately cannot be reduced to those other basic interactions between the basic elements. Some of the examples, cited in the literature, that we can mention as possible emergent phenomena are [9–12]:
physical systems that goes from the transparency of the water (or other liquid), phase transitions, and the so-called self-organized criticality state in granular systems, on one side, to the emergence of space-time at the other end of the physical scope;
biological systems, like the multicellular construct in a given organism, ending ultimately in organs, and the morphogenesis phenomena;
social organization observed in insects, mammals, and in general in every biological system consisting of agents (notice how the combination and interaction of all these subsystems also establish a higher level of emergent phenomena, as one can see, for example, in the biosphere).”
—One atom can’t handle information, but many of them together can form a DNA molecule.
One atom can STORE information under very special circumstances:
#Sessoli, Roberta (2017): “Single-atom data storage”. Nature, vol. 543, 189–190
https://www.nature.com/articles/543189a
Quote: “The ultimate limit of classical data storage is a single-atom magnetic bit. Researchers have now achieved the writing and reading of individual atoms whose magnetic information can be retained for several hours but it can't store large amounts of information nor transfer or communicate by itself that information to the environment, as DNA can.”
However, atoms by themselves can’t handle the volume and complexity of information than a DNA molecule can.
—Molecules are not alive, but many of them can form a cell, and cells are alive. With each jump up the complexity ladder the rules of what is possible changes. Completely new things emerge that are much more than the sum of their parts. And here the reductionist view of the universe breaks down.
By “the reductionist view”, here, we mean the view that the only laws that are really fundamental to explain physical phenomena are those associated to the basic constituents of the universe.
#Anderson, Philip W.(1972): “More is different”, Science, vol.177, 393-396
https://www.science.org/doi/abs/10.1126/science.177.4047.393
https://www.tkm.kit.edu/downloads/TKM1_2011_more_is_different_PWA.pdf
Quote: “That is, it seems to me that one may array the sciences roughly linearly in a hierarchy, according to the idea The elementary entities of science X obey the laws of science Y [...] But this hierarchy does not imply that science X is "just applied Y". At each stage entirely new laws, concepts, and generalizations are necessary, requiring inspiration and creativity to just as great a degree as in the previous one. Psychology is not applied biology, nor biology applied chemistry."
—This is not the whole story. Reality is not only structured in layers but for some reason the layers are also largely independent of each other. Things existing at the same layer can influence each other and maybe a layer up or down. But often they don’t seem to influence things much higher up or down. To figure out how your organs work, you don’t need quarks. To understand politics, you don’t need to know about cells! If you want to explain things happening on one layer, you can only do that by staying close to that layer.
The fact that physical phenomena happening at very different length scales (i.e. very different sizes, or energy regimes) have little or no influence on each other has been emphasized many times in many contexts. From a physics perspective, this phenomenon has been rigorously studied within the framework of the so-called "effective theories" and the (closely related) theory of renormalization.
#Wilson, Kenneth G. (1979): “Problems in Physics with many Scales of Length” Scientific American vol. 241, 2, 158
https://www.scientificamerican.com/article/problems-in-physics-with-many-scale/
Quote: "One of the more conspicuous properties of nature is the great diversity of size or length scales in the structure of the world. An ocean, for example, has currents that persist for thousands of kilometers and has tides of global extent; it also has waves that range in size from less than a centimeter to several meters; at much finer resolution seawater must be regarded as an aggregate of molecules whose characteristic scale of length is roughly 10–8 centimeter. From the smallest structure to the largest is a span of some 17 orders of magnitude.
In general, events distinguished by a great disparity in size have little influence on one another; they do not communicate, and so the phenomena associated with each scale can be treated independently. The interaction of two adjacent water molecules is much the same whether the molecules are in the Pacific Ocean or in a teapot. What is equally important, an ocean wave can be described quite accurately as a disturbance of a continuous fluid, ignoring entirely the molecular structure of the liquid. The success of almost all practical theories in physics depends on isolating some limited range of length scales. If it were necessary in the equations of hydrodynamics to specify the motion of every water molecule, a theory of ocean waves would be far beyond the means of 20th-century science."
—But the emergence argument doesn’t invoke magic. It just says that thinking about free will in terms of determinism and fundamental laws is a dead end. A kind of category error, like trying to explain galaxies by looking at your digestive tract. It is part of a reductionist school of thinking about the universe that very successfully shaped science for a long time – but that is challenged by emergence.
The debate between the strictly reductionist point of view vs. the "emergentist" one is relatively new in science due, in part, to the tremendous success of the reductionist program in the first centuries after the birth of modern science. However, the emergentist approach has been increasingly vindicated in the last decades, especially by scientists working in complex systems. A seminal paper is the already cited:
#Anderson, Philip W.(1972): “More is different”, Science, vol.177, 393-396
https://www.science.org/doi/abs/10.1126/science.177.4047.393
https://www.tkm.kit.edu/downloads/TKM1_2011_more_is_different_PWA.pdf
Quote: “The ability to reduce everything to simple fundamental laws does not imply the ability to start from those laws and reconstruct the universe. The constructionist hypothesis breaks down when confronted with the twin difficulties of scale and complexity. At each level of complexity entirely new properties appear. Psychology is not applied biology, nor is biology applied chemistry. We can now see that the whole becomes not merely more, but very different from the sum of its parts.”
Another influential reference advocating for the emergentist program and its foreseeable importance in the science of the 21st century is this paper by Nobel Prize winner Robert B. Laughlin and David Pines:
#Laughlin, Robert B.; Pines, David (2000): “The Theory of Everything” Proceedings of the National Academy of Sciences, vol. 97, 1, 28-31
https://www.pnas.org/doi/full/10.1073/pnas.97.1.28
Quote: "The Theory of Everything is a term for the ultimate theory of the universe—a set of equations capable of describing all phenomena that have been observed, or that will ever be observed (1). It is the modern incarnation of the reductionist ideal of the ancient Greeks, an approach to the natural world that has been fabulously successful in bettering the lot of mankind and continues in many people's minds to be the central paradigm of physics. [...]
However, it is obvious glancing through this list that the Theory of Everything is not even remotely a theory of every thing (2). [...]
The central task of theoretical physics in our time is no longer to write down the ultimate equations but rather to catalogue and understand emergent behavior in its many guises, including potentially life itself. We call this physics of the next century the study of complex adaptive matter. For better or worse we are now witnessing a transition from the science of the past, so intimately linked to reductionism, to the study of complex adaptive matter, firmly based in experiment, with its hope for providing a jumping-off point for new discoveries, new concepts, and new wisdom."
—Well, just like no individual molecule creates wetness, not a single cell in your brain wants to watch Youtube. But one layer up, your brain made of 80 billion interconnected neurons does. On this layer all the things relevant to you emerge: your consciousness, character, feelings, your fears and dreams. This is where You emerge.
The argument that is being summarized here is that things like “self” or “consciousness” are emergent properties that appear at the organizational level of the brain, and that it is at that level, not the level of isolated neurons and particles, where one can find a causal relation that is meaningful to free will.
#Doyle, Stuart T. (2022): “Free Will, Temporal Asymmetry, and Computational Undecidability”, Journal of Mind and Behavior, vol. 43, 4, 305-321
https://philpapers.org/rec/DOYFWT-2
Quote: "Consider the following question as an analogy: Are apples red? Suppose we all agree that apples have color. The question is whether the color is red or non-red. To answer the question, Sam Harris and Jerry Coyne look beyond the proximate color of the apple. Realizing that the apple is nothing but atoms, they examine many of the carbon atoms on the surface of the apple. They find that not a single carbon atom is red. Since none of the atoms are red, and the apple is nothing but atoms, Harris and Coyne conclude that the apple can’t be red. Their error is that though they agree the apple has a color, they try to examine the nature of the color at a scale where color is incoherent. (A carbon atom is smaller than the wavelength of red light.) The fact that they found no redness at that scale shouldn’t lead them to conclude anything about the redness of the apple.
Likewise, the fact that Harris and Coyne find no personal authorship or freedom in the actions of molecules shouldn’t lead them to conclude anything about the nature of the will. We agree that we have wills, that we have subjectively experienced intentions which cause our actions. The question is whether the will is free or unfree. To look at molecules for the answer is a mistake. DNA and neurotransmitters observed at the molecular scale exhibit no will whatsoever. With that knowledge, should we really find it compelling that molecules exhibit no free will? No. It should tell us that Harris and Coyne are looking at the wrong scale to find answers about the will, just like looking for answers about redness at a scale where there is no color.
The right scale for finding answers to the question of apple redness is the apple scale, not the atom scale. The right scale for finding answers to the question of freedom of the will is the agent scale, not the molecule scale. Searching the molecule scale is just one example of this error."
Though independent from our argument, here is our source for the number of neurons in the average brain of an adult male:
#Azevedo, Federico A.C. et al. (2009): “Equal numbers of neuronal and nonneuronal cells make the human brain an isometrically scaled-up primate brain” Journal of Comparative Neurology, vol. 513, 5, 532-41
https://pubmed.ncbi.nlm.nih.gov/19226510/
Quote: “We find that the adult male human brain contains on average 86.1 +/- 8.1 billion NeuN-positive cells ("neurons") and 84.6 +/- 9.8 billion NeuN-negative ("nonneuronal") cells.”
—How all the things going on in your brain play off each other to make you who you are is a whole different can of worms – but on this layer of reality, you are part of the decision process. Because, at this level, “you” are just one more physical cause of whatever happens in your brain. You are shaped by your decisions and your decisions are shaped by you. You have a say on this layer of reality.
We thank MIT philosophy professor Agustín Rayo, who we consulted for this video, for the following quote:
Quote: “When attention is restricted to the level of reality that is relevant to discuss free will, there is no way of explaining why an agent ended up performing the actions they performed without making the agent itself part of the explanation." In other words, the agent itself "causally affects events in a way that, at the relevant level of reality, is not determined by prior events.”
In other words, the agent itself "causally affects events in a way that, at the relevant level of reality, is not determined by prior events."
This "causal effect of the agent on their decisions" has been emphasized, among others, by author and science writer Philip Ball:
#Ball, Philip (2021): “Why free will is beyond physics”, Physics World, 34, 1, 17
https://physicsworld.com/a/why-free-will-is-beyond-physics/
Quote: "The sceptical physicist might then ask: so where does this “free will” come from that enables events to turn out differently than they might have? In response, we should turn the question around: what exactly caused events to turn out as they did? The underlying problem here is that the reducibility of phenomena – which is surely valid and well supported – is taken to imply a reducibility of cause. But that doesn’t follow at all. What “caused” the existence of chimpanzees? If we truly believe causes are reducible, we must ultimately say: conditions in the Big Bang. But it’s not just that a “cause” worthy of the name would be hard to discern there; it is fundamentally absent.
To account for chimps, we need to consider the historical specifics of how the environment plus random genetic mutations steered the course of evolution. In a chimp, matter has been shaped by evolutionary principles – we might justifiably call them “forces” – that are causally autonomous, even though they arise from more fine-grained phenomena. To complain that such “forces” cannot magically direct the blind interactions between particles is to fundamentally misconstrue what causation means. The evolutionary explanation for chimps is not a higher-level explanation of an underlying “chimpogenic” physics – it is the proper explanation. [...]
If we recognize, as we should, that the origins of volitional decision-making lie in evolutionary biology, we must accept that the entire mode of its operation – the way in which brains imbued with innate tendencies and learned information process low-resolution stimuli – doesn’t share an epistemic language with Newtonian and quantum mechanics. To talk about causation in science at all demands that we seek causes commensurate with the phenomena: that’s simply good science and good epistemology.”
—But even if we don’t have free will, it’s not clear what that changes for practical purposes.
The existence of free will has deep implications in morality and, consequently, law.
#Stanford Encyclopedia of Philosophy: “Free Will: Free will and moral responsibility” (retrieved 2024)
https://plato.stanford.edu/entries/freewill/#FreeWillMoraResp
Quote: “It is worth observing that in many of these disputes about the nature of free will there is an underlying dispute about the nature of moral responsibility. This is seen clearly in Hobbes (1654 [1999]) and early twentieth century philosophers’ defenses of compatibilism. Underlying the belief that free will is incompatible with determinism is the thought that no one would be morally responsible for any actions in a deterministic world in the sense that no one would deserve blame or punishment. Hobbes responded to this charge in part by endorsing broadly consequentialist justifications of blame and punishment: we are justified in blaming or punishing because these practices deter future harmful actions and/or contribute to reforming the offender (1654 [1999], 24–25; cf. Schlick 1939; Nowell-Smith 1948; Smart 1961). While many, perhaps even most, compatibilists have come to reject this consequentialist approach to moral responsibility in the wake of P. F. Strawson’s 1962 landmark essay ‘Freedom and Resentment’ (though see Vargas (2013) and McGeer (2014) for contemporary defenses of compatibilism that appeal to forward-looking considerations) there is still a general lesson to be learned: disputes about free will are often a function of underlying disputes about the nature and value of moral responsibility.”
However, the extent of how much and what about free will matters for moral responsibility, and even if personal responsibility should determine punishment by law, is still open.
#Encyclopedia Britannica: “Compatibilism” (retrieved 2024)
https://www.britannica.com/topic/free-will-and-moral-responsibility/Compatibilism
Quote:“Although the central issues involved in the problem of free will and moral responsibility have remained the same since ancient times, the emphasis of the debate has changed greatly. Contemporary compatibilists in the vein of Frankfurt and Strawson tend to argue that moral responsibility has little if anything to do with determinism, since it arises from people’s desires and attitudes rather than from the causal origins of their actions. Humans may not be free to as great an extent as the intuitive notion of free will suggests, but there is no other freedom to be had. Addressing the problem of free will and moral responsibility requires establishing guidelines for holding people accountable, not lunging after some impossible notion of free will.
Contemporary libertarians in the vein of Chisholm, on the other hand, continue to maintain that moral responsibility requires a certain kind of robust free will that compatibilism does not allow for. Their prime concern is to untangle the metaphysical issues underlying the intelligibility objection and to make room for free will in an indeterministic world.
How much of human behaviour is determined by past events, and how much does this matter—if it does matter—for free will and moral responsibility? In the end, the important question may be not whether the universe is deterministic or indeterministic but whether one is willing to accept a definition of free will that is much weaker than intuition demands.”