The failures of phlogiston and vitalism are historical hindsight. Dare I step out on a limb, and name some current theory which I deem analogously flawed?

    I name emergence or emergent phenomena—usually defined as the study of systems whose high-level behaviors arise or “emerge” from the interaction of many low-level elements. (Wikipedia: “The way complex systems and patterns arise out of a multiplicity of relatively simple interactions.”)

    Taken literally, that description fits every phenomenon in our universe above the level of individual quarks, which is part of the problem. Imagine pointing to a market crash and saying “It’s not a quark!” Does that feel like an explanation? No? Then neither should saying “It’s an emergent phenomenon!”

    It’s the noun “emergence” that I protest, rather than the verb “emerges from.” There’s nothing wrong with saying “X emerges from Y,” where Y is some specific, detailed model with internal moving parts. “Arises from” is another legitimate phrase that means exactly the same thing. Gravity arises from the curvature of spacetime, according to the specific mathematical model of General Relativity. Chemistry arises from interactions between atoms, according to the specific model of quantum electrodynamics.

    Now suppose I should say that gravity depends on “arisence” or that chemistry is an “arising phenomenon,” and claim that as my explanation.

    The phrase “emerges from” is acceptable, just like “arises from” or “is caused by” are acceptable, if the phrase precedes some specific model to be judged on its own merits.

    However, this is not the way “emergence” is commonly used. “Emergence” is commonly used as an explanation in its own right.

    I have lost track of how many times I have heard people say, “Intelligence is an emergent phenomenon!” as if that explained intelligence. This usage fits all the checklist items for a mysterious answer to a mysterious question. What do you know, after you have said that intelligence is “emergent”? You can make no new predictions. You do not know anything about the behavior of real-world minds that you did not know before. It feels like you believe a new fact, but you don’t anticipate any different outcomes. Your curiosity feels sated, but it has not been fed. The hypothesis has no moving parts—there’s no detailed internal model to manipulate. Those who proffer the hypothesis of “emergence” confess their ignorance of the internals, and take pride in it; they contrast the science of “emergence” to other sciences merely mundane.

    And even after the answer of “Why? Emergence!” is given, the phenomenon is still a mystery and possesses the same sacred impenetrability it had at the start.

    A fun exercise is to eliminate the adjective “emergent” from any sentence in which it appears, and see if the sentence says anything different:

    • Before: Human intelligence is an emergent product of neurons firing.
    • After: Human intelligence is a product of neurons firing.
    • Before: The behavior of the ant colony is the emergent outcome of the interactions of many individual ants.
    • After: The behavior of the ant colony is the outcome of the interactions of many individual ants.
    • Even better: A colony is made of ants. We can successfully predict some aspects of colony behavior using models that include only individual ants, without any global colony variables, showing that we understand how those colony behaviors arise from ant behaviors.

    Another fun exercise is to replace the word “emergent” with the old word, the explanation that people had to use before emergence was invented:

    • Before: Life is an emergent phenomenon.
    • After: Life is a magical phenomenon.
    • Before: Human intelligence is an emergent product of neurons firing.
    • After: Human intelligence is a magical product of neurons firing.

    Does not each statement convey exactly the same amount of knowledge about the phenomenon’s behavior? Does not each hypothesis fit exactly the same set of outcomes?

    “Emergence” has become very popular, just as saying “magic” used to be very popular. “Emergence” has the same deep appeal to human psychology, for the same reason. “Emergence” is such a wonderfully easy explanation, and it feels good to say it; it gives you a sacred mystery to worship. Emergence is popular because it is the junk food of curiosity. You can explain anything using emergence, and so people do just that; for it feels so wonderful to explain things.

    Humans are still humans, even if they’ve taken a few science classes in college. Once they find a way to escape the shackles of settled science, they get up to the same shenanigans as their ancestors—dressed up in the literary genre of “science,” but humans are still humans, and human psychology is still human psychology.

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    Hmm, interesting. I've never actually realized that people used "emergent behavior" as a model or an explanation for anything. In that context, I'd always treated it as just a description, with the meaning that an "emergent phenomenon" is a "complex or seemingly complex phenomenon arising from interactions of a large number of very simple subparts," or something of the sort. Never thought of it as a model or an explanation, but just as a reasonable descriptive word. But if it is used as an attempted explanation to end discussion, then it's just functioning as a curiosity-stopper and should be questioned further.

    What are phenomena that aren't "emergent"? I guess Eliezer is right when he says "a single quark". I think Eliezer makes a good case that the word is overused, and doesn't enlighten the discourse.

    It might be more useful to describe things in reverse " X are the components of phenomenon Y". Such as "Neurons firing are the known components of intelligence". Because when we observe something, it can be useful to ask "what are its components"?

    It contrast, everything observed IS the component of some bigger syst... (read more)

    Okay, but that's really not how I have understood emergence. It delineates a subject matter, and does so in an abstract way that includes many specific examples which are purportedly alike in some important way. But I don't think this use necessarily implies that the explanation has thereby been given. It is, rather, usually an attempt to delineate a subject matter which can be further investigated. I believe that the hope is that a general theory of emergence is possible, though my impression is that there isn't even a generally agreed-upon definition of it, let alone a commonly accepted theory.

    One common element that I have sometimes noticed is that an emergent phenomenon can be idealized and a simplified mathematical model constructed of it, which is not precisely correct but which is a very good approximation. The existence of such simple and very good models is remarkable and extremely lucky for us.

    For example, an actual fluid such as water is really made up of molecules that interact, but there is a simple mathematical model for fluids which treats fluids as absolutely continuous and smooth all the way down, not composed of atoms but fluid at every scale. As I vaguely recall,... (read more)

    In line with previous comments, I'd always understood the idea of emergence to have real content: "systems whose high-level behaviors arise or 'emerge' from the interaction of many low-level elements" as opposed to being centrally determined or consciously designed (basically "bottom-up" rather than "top-down"). It's not a specific explanation in and of itself, but it does characterise a class of explanations, and, more importantly, excludes certain other types of explanation.

    I would think that something like "life/intelligence is an emergent phenomenon" means "you don't need intelligent design to explain life/intelligence".

    I remember when Warren Spector & Harvey Smith were going on about emergence in videogames. I think their definition was something like "a non-obvious [it may even surprise the designers] outcome of a system of rules rather than something scripted". That's a rather subjective definition but it seems to fit as well for the things that are described as "emergent" in real life. Since life is not actually a videogame but has universally valid rules, it would not be a very useful concept for that domain. I think Wolfram has written a lot ... (read more)

    I'm getting the feeling that Eliezer is starting to get overly eager to attack semantic stopsigns. I recommend magic oil in the evening and emergent phenomena in the morning.

    My impression of "emergence" was that it's closely related to pattern recognition. You have atoms A, B..ZZZZZZZZZZ, and you recognize that these atoms form a certain pattern. So you say that a supercluster of galaxies/bar stool/intelligence "emerges" from a bunch of atoms.

    I once had a prolonged debate with an anticognitivist. He, as usual, argued that no matter what... (read more)

    Isn't his usage of "switches flipping" basically another 'literary genre' switch--i.e. he had attached some sort of negative connotation to the phrase which he could not conceive of attaching to intelligence?

    Aren't superconductivity and ferromagnetism perfect examples of emergent phenomena? I'm not saying that calling something an emergent phenomenon adds any deeper understanding of it. But I think there certainly are phenomena that can be fairly called as emergent.

    Aren't superconductivity and ferromagnetism perfect examples of emergent phenomena?

    Yes. So are non-superconductivity and non-ferromagnetism. That's the problem.

    Uh. No. Non-superconductivity is not usually considered as an example of emergence. Because the non-superconductive system is composed of smaller subsystems which are themselves non-superconductive. Same goes for non-ferromagnetism. Not "emergent" because nothing new is emerging from the collective that was not already present in the components.

    And even if what you wrote were true it would be a problem only if emergence were being used as an explanation. But, outside of the philosophy literature, it almost never is used that way. You are tilting at windmills here.

    Non-superconductivity means that moving electrons through it will result in the atoms moving unpredictably. It is a product of how electrons and atoms interact. It is less emergent than how, if they interact a different way, the atoms will not start moving unpredictably. It's made up of non-superconductive subsystems in that if you take a little piece of it, that will be non-superconductive, but the same applies to a superconductor. You can't just take one atom and say whether or not it's superconductive. A current can't flow through one atom in a relevant sense.
    I think that the point is that emergence is in the mind of the observer. If the observer is describing the situation at the particle level, then superconductivity is not there regardless of the size of the collection of particles considered. But, when you describe things at the flowing-electric-fluid level, then superconductivity may emerge.
    Aren't the labels arbitrary? Let's use sharpness. Let's use bluntness. That humans say "sharp", "blunt", "conductive", and "non-conductive" in English is due to circumstances of culture, technology, what minerals are abundant on Earth, etc. At least, I don't know the word, if there is one, for non-conductive. To the extent "sharp" and "blunt" are not opposites, I apologize for the imperfect example.
    Conductivity isn't there either unless you describe them at the flowing-electric-fluid level.
    The apparent disagreement here, comes from different understandings of the word "non-superconductivity". By "non-superconductivity", Yudkowsky means (non-super)conductivity, i.e. any sort of conductivity that is not superconductivity. This is indeed emergent, since conductivity does not exist at the level of quantum field. By "non-superconductivity", Perplexed means non-(superconductivity), i.e. anything that is not superconductivity. This is not emergent as Perplexed explained.
    It seems to me that emergence is the opposite of rigorous structure. Take human brain function (similar to your intelligence comment in the article). Claiming that brain function is emergent versus rigorously ordered allows you to make a prediction, namely that a child who has a portion of their brain removed will retain all or a large portion of the functionality of the removed portion, or they will not. A child with half of their brain missing would be expected to be extraordinarily impaired. A simple search of the literature should prove it one way or another. Thus, when one says that some property is emergent, it means that it is not limited by the macro form, but by the conditions effecting the micro components from which the property emerges. This should allow for all manner of predictive ability. Of course, there are plenty of people who latch on to the word, just like there are plenty of people who latch on to the word "evolution", and don't think or use it to make predictions, and in that, your point is well taken. Sorry for commenting 5 years after the fact, but this place seems to have at least some ongoing discussion.
    3Swimmer963 (Miranda Dixon-Luinenburg)
    According to this, a child with half of their brain removed can sometimes do just fine. It has a lot to do with age, though, given that children have more neuroplasticity–a fully functioning adult would probably lose a lot of their normal abilities.
    "Holistic" seems to label that phenomenon more clearly, for my money.

    I don't buy the analogy between emergence and phlogiston or vitalism. Offering up "emergence!" as an explanation of a phenomenon is a category mistake, to be sure, and is a semantic stopsign when misunderstood this way.

    As other commenters have noted, however, there is a proper understanding of emergence that is useful. (In philosophy, for instance, it's an admittedly sloppy but still useful term to classify different kinds of explanations of consciousness). This doesn't seem true of explanations that appeal to phlogiston or vitalism. Vitalist explanations aren't category mistakes. They're simply vacuous explanations, full stop.

    Sean, that's a useful link. The "irreducible-pattern" epistemological version of emergence, described there, is one I'd heard before. It definitely wouldn't fit everything (if I had to bet, I'd bet it fits nothing).

    Creeping into his soul, he felt the first faint tinges of despair.

    After all these posts on how the strength of an idea is what it excludes, forbids, prohibits, people are still citing positive examples as proof of the power of emergence? Tell me what it isn't!

    Emergence is NOT the sum of the parts. I'm curious, Eliezer, what you think of Alex Ryan's and Cosma Shalizi's definitions/formalisms of emergence? The both seem to be claiming that emergence is more than you are, but that could be an illusion...
    You ITprimer seems to disagree with your statement: ITprimer: Non-trivial interactions of individual components -> Self organization -> New behaviors labeled to have 'emerged' Where did they emerge from? The non-trivial interactions. This description runs counter to your discription "Emergence is NOT the sum of the parts." It is the sum of the non-trivial parts by the above description and a loose definition of sum.
    The even/odd attribute of a collection of marbles is not an emergent phenomenon. This is because as I gradually (one by one) remove marbles from the collection, the collection has a meaningful even/odd attribute all the way down, no matter how few marbles remain. If an attribute remains meaningful at all scales, then that attribute is not emergent. If the accuracy of fluid mechanics was nearly 100% for 500+ water molecules and then suddenly dropped to something like 10% at 499 water molecules, then I would not count fluid mechanics as an emergent phenomenon. I guess I would word this as "no jump discontinuities in the accuracy vs scale graph."
    I don't understand this comment. Two posters had offered only positive examples. Five had offered at least one negative example in contrast to a positive example.
    To respond to a really old comment - Emergence does exclude some possibilities. For example, if consciousness is emergent, it means that it's not ontologically basic, it's not caused by something outside the system, and that it exists.
    1Max Hodges
    Thanks. But why does he dismiss each idea? That sounds true to me, but he says it's too ubiquitous "so this is surely not what we mean." Uh, why discredit something because it explains a lot of things?? Oddly, he systematically discredits each idea because they don't suit his tastes.


    What isn't emergence? Well, on a trivial level, everything observable is a consequence of physics. So, is there anything observable that does not fall into the category of "physics", and does that make the category meaningless?

    I think I can come up with some things that "emergence" is not.

    If X is not "emergent", then: a) X does not have a cellular automata-like model; there are no readily identifiable components of X that follow relatively simple, computable rules which generate the observed behavior of the system. (The... (read more)

    "Black holes, dark matter and dark energy seem to pretty much fit this description. They are, after all, inventions tacked on to calculations, in order to make theory and calculation fit observations."

    See for dark matter.

    There are a few examples of non-emergence. For example, if we tessellate many small equilateral triangles to create a larger equilateral triangle, the resulting figure will not show any emergent properties.

    Outside of mathematics, though, the concept is vague and I can't see much use for it as applied to specific phenomena.

    For example, if we tessellate many small equilateral triangles to create a larger equilateral triangle, the resulting figure will not show any emergent properties.

    On the contrary - the large shape emerges from all the small shapes! Isn't it wonderful? You can even get the same behavior on the higher level as on the lower level, only this time, it's emergent! what an emergence advocate would say, if they wanted to claim yet more territory for their ever-growing kingdom.

    If we take EY's example of a market crash, the non-emergent hypothesis is that of a random process. In other words, price action is like the action of gas molecules, or Brownian motion. To say that a market crash is an emergent phenomenon is to say that it displays more order than gas molecules bouncing off one another, which do not display emergent properties. That is not an empty distinction, as far as I can see.

    Eliezer: I generally like your posts, but I disagree with you here. I think that there's at least one really useful definition of the word emergence (and possibly several useless ones).

    It's true, of course (at least to a materialist like me), that every phenomenon emerges from subatomic physics, and so can be called 'emergent' in that sense. But if I ask you why you made this post, your answer isn't going to be, "That's how the quarks interacted!" Our causal models of the world have many layers between subatomic particles and perceived phenomena. Emergence refers to the relationship between a phenomenon and its immediate cause.

    So, for instance, suppose I'm on the interstate and I get caught in a traffic jam. I might wonder why there's a huge jam on the road. It's possible that there's a simple, straightforward explanation: "There's a ten-car pileup a mile further on, and five of the six lanes are shut down. That's why there's a traffic jam." Obviously we could get far more reductionist— both in terms of "why is there a pileup" and "why does a pileup cause a traffic jam"—but for the conceptual level we're operating on, the pileup is a f... (read more)

    I've actually seen a study on these types of jams, though I cannot remember the source. The results were pretty simple and surprising. The research discovered they could create a massive traffic jam on a full but still flowing highway by simply having a single car brake for longer than necessary. The first person would brake for too long, causing the person behind him to brake for slightly longer (he isn't likely to brake for less time than the person ahead of him lest he risk an accident), which continued down the line, a chain reaction. Drivers in the lanes on either side of the initial brake chain would also begin braking as they saw people in the central lane brake, being sensibly cautious during rush hour, which would spread outward from their positions. Eventually traffic would halt, as the people ahead would have to stop completely before being able to move again. I'm sure there was some kind of cutoff threshold regarding how long over the necessary length of time the first person has to break, but it wasn't very long, a second or two would do it during a non-jammed rush hour. It also explains why, once a jam occurs for any reason, it is extremely slow to clear up even after the cause of the jam is long since removed. Pretty shocking really, and certainly not an "emergent phenomena". That's why EY is against using emergence for everything - there absolutely must be a reason, and that reason cannot be "lots of stuff interacts and now we get a traffic jam!" Using emergence as an explanation encourages you to stop thinking about the problem, rather than dig in and figure out why what happened happens. You have unexplained traffic jams - do you call it emergence or try to explain them? The rational thing to do is to try to explain them in a way that allows you to have expectations about future observations. In other words, "Emergence" is an answer looking for a problem.
    "Emergence" here would be a reference to the non-linear result of the braking. Like what Henry_V said.
    Yes, the point is to be sure you aren't using "Emergence" or "Emergent Phenomena" as stop signs. That you recognize that there is in fact a cause (or causes) for what you are seeing, and if the total seems to be more than the sum of its parts, that there is some mechanism that exists that is amplifying the effects. Emergence is not an explanation by itself.

    I want to say that I like Jadagul's reply

    "Even better: A colony is made of ants. We can successfully predict some aspects of colony behavior using models that include only individual ants, without any global colony variables, showing that we understand how those colony behaviors [emerge] from ant behaviors."

    Emerge and arise are synonyms. I'll agree with your desire to quell the potential overuse of "emergent," however as is well outlined above there is a specific testable model being proposed when emergent is used closer to correctly. That is that there is no system-wide varia... (read more)

    In most of the contexts in which I have seen the word "emergent used", it has signified a lack of understanding of the underlying causes of the phenomenon being described but rather than acting as a semantic stop-sign seemed to be used as its exact oppposite - as a marker for an area sufficiently interesting to be deserving of further research with a view to eventual full explanation. But perhaps I've been misunderstanding the intent of the authors.

    "After all these posts on how the strength of an idea is what it excludes, forbids, prohibits, people are still citing positive examples as proof of the power of emergence? Tell me what it isn't!"

    I thought I did. (Even if Jadagul expressed what I was grasping towards much better than I did.)

    I'm pretty ignorant on this, but I always thought that the phrase related to complex outcomes that result from surprisingly simple systems, so that the complexity is "emergent".

    One example is chaos. One can have chaotic non-linear dynamic systems and non-chaotic non-linear dynamic systems.

    But, again, I could have misunderstood.

    Jadagul's example seems to me to be a clear place where the term emergence is useful. Phil Goetz has given others in the past. OTOH, it still seems that in most of the cases where emergence is used as a synonym for "magic" much too often. 'Emerges from' seems to be less strong evidence for a legitimately useful term than than 'emergent', as 'chaotic' seems to be a perfect synonym for the latter.

    Even in the case of 'chaotic', the tendency to use the term as a stop-sign is serious. A great deal of understanding of chaotic systems is possible (t... (read more)

    We can successfully predict some aspects of colony behavior using models that include only individual ants, without any global colony variables, showing that we understand how those colony behaviors arise from ant behaviors.

    But that is just what is meant to be conveyed by the claim that intelligence emerges from the interaction of neurons. Of course that is trivially true. But, the original AI theory was that neurons were the building blocks of a universal computer (and how the universal computer was built of neurons wasn't particularly interesting). Th... (read more)

    "Tell me what it isn't!"

    I'll go with TGGP's domain (video games), since that is what we blog about at Kill Ten Rats. The gaming blogosphere uses the term "emergent gameplay" more or less as TGGP defines it. Going back to my first online game, Asheron's Call, an example of what is not "emergent" gameplay is characters slaying monsters and leveling up. Monsters have the same code, but rarely win, so they rarely level; an example of emergent play was having characters sacrifice themselves to bunnies, who would gradually level ... (read more)

    "Tell me what it isn't!"

    The examples I gave, superconductivity and ferromagnetism, are example of phase transitions, which only happen when there are large number of components interacting. I wouldn't call phenomena that can be explained by one or few components as emergent. So, I wouldn't call a black hole as emergent. I wouldn't call an electron and a proton making up a hydrogen atom as emergent. I wouldn't call two hydrogen atoms and an oxygen atom forming a water molecule as emergent. But liquid that is formed by a large number of water molecules is an emergent phenomenon to me. Jagadul's example of traffic jam is also a good one.

    I'm pretty out of my depth here, but I'll echo what some people have said above. Before people started scientifically doing either one, would it have been obvious that a simple model would be very successful at predicting the behavior of, say, subatomic particles but would be very unsuccessful at predicting the weather? That is, it seems like there really are some phenomena where it is more true and others where it is less true that predictions can be generally and successfully made using straightforward intuitive models. It seems like the label "emergent" is just a (useful) label for the stuff where this can't be done.

    Tom McCabe, that is not proof.

    BJK is on to something: the non-emergent description of a market crash is something like "IF the Fed is raising rates and the economy is slowing down and investors are too leveraged and ... ... ... then the market will crash," while the emergence theory might define investor behavior and note that it will result in periodic booms and crashes, without special rules to govern either. That's the essence of emergence: simple universal rules rather than complex specific rules.

    It might feel like junk science because it crosses disciplinary borders, but that doesn't make it invalid.

    Don't y'all find it a little suspicious that so many people think "emergence" is a useful concept, yet have different definitions of what it is? (Though more important is what it isn't.)

    Next stage in the gauntlet: Why is this a useful concept? Why does it increase your understanding of the universe, and your predictive power? Can you force me to talk about emergence or a concept isomorphic to it?

    I think you are railing against the way emergence is used as opposed to itself as a theory. Emergence theory can be helpful in breaking down complex systems to gain a better understanding of how they work. If the behavior of a system is dominated by a decentralized and internal control mechanism, then it is emergent. If the behavior is dominated by a centralized or an external control mechanism then it is non-emergent. Let's take for an example the complex movement of a bee swarm. From casual observation, it looks to be a single entity that has an intelligence of itself. As a layman, upon looking at this, I could take a guess that perhaps it is magic, or the Queen bee is in full control somehow. If somebody tells me that it is in fact emergent, then I can understand and predict the bee swarm much more accurately. I can see that each individual bee's behavior influences it's neighbor's in such a way to produce a highly complex and sophisticated system. I will be able to model and predict the swarm much more accurately than if I thought it was controlled by the Queen via pheromones, for example. This theory also has the luxury of being testable. Also, we can use emergence as an approach engineering problems as well. Since video games were used as an example before, let's use them again. Say we wanted to make a game where the player is being chased by formations of monsters. One approach would be to create a computer AI to direct the monsters in a line and move towards the player. This would be non-emergent. Another would be to create the monsters as individual objects that move towards the next nearest monster and also towards the player but at a slower rate. This would tend create clusters of monsters that charged towards the player. Now, what if had the monsters move towards the player and the next nearest monster, but away from the second nearest monster. This would tend to create lines of monsters that moved towards the player. So, to force you to talk about
    Does an emergent bee swarm follow the same rules as an emergent market? That is, can you take the rules of emergence and apply them to both as is - including only the necessary details (like how many bees or the number of stocks)? If so, you have a testable theory. If not, you have phlogiston. As Wikipedia describes them, "weak emergence" seems to be what the people above are talking about - that is the properties of the whole can be described/predicted by the interactions of its parts, and "strong emergence" which says the properties of the whole cannot be described/predicted by the interaction of its parts - seems to be what EY is talking about. The notion of strong emergence, to me, seems nonsensical. I also see no formula for emergence of any kind, which suggests to me that it is not intended to make any predictions - only describe events after they occur. That sounds a lot like phlogiston to me.

    I disagreed Rip's opinion that black holes etc. are examples of emergent phenomena, but other than that I don't really see much disagreement about what emergence is in the comments here.

    I like Zubon's description "the whole is not predictable from the parts" and "No cell in your brain understands Chinese,..., but the system as a whole does."

    Why can it be useful? I can think of two possible reasons. There is a certain reductionist tendency (although I don't think being reductionist per se is bad) to assume that we get better and better... (read more)

    The concept of emergence is useful as a guard against certain errors, such as, for example, conspiratorial theories which explain phenomena as the product of intentions (malign or benevolent). Order does not always arise from intention. If society is lawful, that is not necessarily because there is some commander dictating that it be lawful. The lawfulness of society may be a phenomenon with a mostly dispersed, decentralized cause (e.g., lawfulness may be in large part enforced by ostracism of transgressors and thus enforced by all members of society rathe... (read more)

    "Tom McCabe, that is not proof."

    There is no such thing as proof. See

    Mainstream astronomers' predictive abilities are shoddy at best. It seems as if every new observation is "surprising," or "shocking," or "baffling."

    Yet there are still no direct observations of dark matter.

    How deep can biases run? Could it have poisoned the very foundation of modern science? I think it's something to investigate, especially considering the vast sums of money that are at stake if some mainstream theories turn out to be wrong or pointless.

    I think you are confused about what dark matter is believed to be. Dark Matter is believed to be non-baryonic matter. Simple as that. We have direct observations of non-baryonic matter. The largest telescopes in the world are actually designed to detect non-baryonic matter (and they succeed). They have to be buried deep in the earth because it is too easy to get noise from various types of radiation, but this is no problem, because non-baryonic matter doesn't interact with ordinary matter except in the rarest of situations. Neutrinos are probably the most well known type of Dark Matter, and those have certainly been directly observed. Scientists are even reasonably certain of the tonnage of neutrinos produced each year by our Sun. There are believed to be other types of Dark Matter, but the nature of the particles make them extremely difficult to study. But not impossible. The point is that expectations don't match up with reality, and the only sensible explanation is that the difference is caused by non-baryonic matter (since if it were baryonic, we'd almost certainly be able to see it). You can make predictions about what you should find based this theory, which can then be falsified. Dark Matter is falsifiable. That's probably the most important thing to know about it.
    I don't think neutrinos are usually referred to as dark matter. Dark matter is whatever solves the problem of "What the hell is all the rest of this mass we can only detect gravitationally", and neutrinos don't solve that problem. And counting neutrinos as dark matter simply because they aren't baryons seems a bit silly, seeing as electrons aren't either. Rather, I should say, dark matter is whatever solves that problem, subject to the constraint of it being a new type of matter operating essentially as usual under ordinary general relativity. Otherwise I guess it would be unfalsifiable. :) The dark matter hypothesis is really just the "Yes, GR really is correct (at large scales)" hypothesis.
    Neutrinos are included in the broad consideration of dark matter because they don't interact electromagnetically. "Baryonic" and "baryon" aren't quite the same; baryonic matter only needs to be composed mostly of baryons. Yes. There's "dark matter" simply defined as matter that doesn't participate in the electromagnetic interaction, and then there's the hypothesis that a significant portion of matter in the universe can be classified as such.
    Ah, OK. Wasn't aware of that distinction. I also failed to notice that the important consideration here is interacts electromagnetically vs. doesn't. Thanks.
    Yes, there are a number of hypothetical non-atomic particles that would need to exist as well, since by their very nature neutrinos have almost no mass. These additional particles have not been discovered, and discovering them would be extremely difficult. I'd agree that it has the potential to be another phlogiston, but you've got to at least give the Dark Matter theorists a chance to falsify their theory. If it becomes a situation where new evidence comes out that DM can't predict, yet is adapted to describe DM, then you know DM is utter poppycock. There are, however, a number of avenues for experimentation, so it's certainly not the case that you can call Dark Matter a modern-day phlogiston yet. At the same time, if DM is poppycock, then GR is necessarily very, very broken (we already know it's broken, just not for big stuff).
    I should note, I was not claiming it to be unfalsifiable, I was just picking nits (incorrectly). :P

    "It seems as if every new observation is "surprising," or "shocking," or "baffling." "

    Surely the underlying reality of this "seeming" is that a large fraction of new newsworthy observations is "baffling" etc.

    I ll try a silly info-theoretic description of emergence:

    Let K(.) be Kolmogorov complexity. Assume you have a system M consisting of and fully determined by n small identical parts C. Then M is 'emergent' if M can be well approximated by an object M' such that K(M') << n*K(C).

    The particulars of the definition aren't even important. What's important is this is (or can be) a mathematical, rather than a scientific definition, something like the definition of derivative. Mathematical concepts seem more about description, representation, and modeling ... (read more)


    I don't have any direct quotes or statistics available at hand, but I think however that it is not disputed that our understanding of the universe is nowhere near complete. And with so many newsworthy observations that don't fit mainstream theory, then surely that must suggest a problem with the theory.

    The shape of galaxies could not be explained with visible matter. As a result, the theory wasn't scrapped; they instead simply added enough matter to the equation to make it work -- hence dark matter (which has to have much more mass than visible matter... (read more)

    If you look through a telescope and expect to see a planet, but instead you see a planet and two moons, do you assume your telescope is broken? That seems to be what you are advocating. I also think you are blind to the fact that there are particles that we know to exist (not by calculation but by direct observation) that are impossible to detect with an optical or radio telescope, for the simple fact that they barely interact with ordinary matter at all. That makes counting them and adding them up through a telescope impossible (that's how they discovered the discrepancy, btw). In light of that evidence, the most plausible explanation is that there is a big mass of this stuff floating around that we simply cannot see. We need to be sure it isn't there before we decide the theory is wrong. Now, if there is strong evidence that Neutrinos and their ilk are not the cause of all the extra gravity, then we have to take a very hard look at General Relativity, which is what predicted the movement of the galaxy in the first place.

    Eliezer: "Don't y'all find it a little suspicious that so many people think "emergence" is a useful concept, yet have different definitions of what it is?"

    That's a non sequitur. Different people define intelligence differently, so what? The fact that they don't understand intelligence doesn't mean that it isn't a useful concept.

    When people actually can't agree on the meaning of a word, the signnal to noise ratio drops from using it. But in that case, instead of discarding the word, people just need to standardize it.

    Emergence is an annoyingly vague concept, but that doesn't mean it's an empty one.

    One meaning of emergence is "decentralized control". In a free market economy, prices and other properties are emergent from a large set of transactions among distributed agents, in contrast to a centrally planned and controlled economy. So there's something that is not emergent, or less emergent. Similarly, it used to be thought that a bee colony was controlled by the queen, but now we know that its activity is also the result of the work of distributed agents. I... (read more)

    "Let K(.) be Kolmogorov complexity. Assume you have a system M consisting of and fully determined by n small identical parts C. Then M is 'emergent' if M can be well approximated by an object M' such that K(M') << n*K(C)."

    That seems to describe what I described earlier:

    "One common element that I have sometimes noticed is that an emergent phenomenon can be idealized and a simplified mathematical model constructed of it, which is not precisely correct but which is a very good approximation."

    I didn't, by the way, intend this as a definition of emergence, though it or something thereabouts might qualify.

    Eliezer: Here's another example similar to ones other people have raised, a story I heard once, that might explain why I think it's an important and useful concept.

    Supposedly, in the early nineties when the Russians were trying to transition to a capitalist economy, a delegation from the economic ministry went to visit England, to see how a properly market-based economy would work. The British took them on a tour, among other things, of an open-air fresh foods market. The Russians were shown around the market, and were appropriately impressed. Afterward... (read more)

    In line with previous comments, I'd always understood the idea of emergence to have real content: "systems whose high-level behaviors arise or 'emerge' from the interaction of many low-level elements" as opposed to being centrally determined or consciously designed (basically "bottom-up" rather than "top-down"). It's not a specific explanation in and of itself, but it does characterise a class of explanations, and, more importantly, excludes certain other types of explanation.

    This comment hits the bullseye. The general idea of... (read more)

    In line with previous comments, I'd always understood the idea of emergence to have real content: "systems whose high-level behaviors arise or 'emerge' from the interaction of many low-level elements" as opposed to being centrally determined or consciously designed (basically "bottom-up" rather than "top-down"). It's not a specific explanation in and of itself, but it does characterise a class of explanations, and, more importantly, excludes certain other types of explanation.

    This comment hits the bullseye. The general idea of... (read more)

    "As a result, the theory wasn't scrapped;"

    By "the theory" you mean general relativity, which is one of the most well-confirmed theories in all of physics. You can't just come up with a slightly modified version of GR to accommodate weird observations; the Einstein field equation is a unique solution because of all the demands placed on any reasonable theory of gravity. If you assume:

    • Spacetime is flat in the absence of matter;
    • Spacetime curvature is linear with respect to the density of matter;
    • The standard principles of mathematics (e
    ... (read more)

    Eliezer, I wonder whether the reason you think "emergence" isn't a useful concept is just that it seems so obvious to you that every phenomenon must fit the proposed definition that it doesn't exclude anything that's meaningful for you. (This seemed to be implied in your original post.) Even so, it can still be a useful concept as long as some people think that there could be non-emergent phenomena.

    And yes, the proposed definitions of emergence are vague, but, as has already been pointed out, that doesn't imply the concept is worthless.

    "Don't y'all find it a little suspicious that so many people think "emergence" is a useful concept, yet have different definitions of what it is?"

    I think "bias" is a useful concept, despite the tendency for people to disagree over what regions of failurespace count as "bias." (Uh, ahem).

    Some other vague concepts people disagree on: 'cause,' 'intelligence,' 'mental state,' and so on.

    I am a little suspicious of projects to 'exorcise' vague concepts from scientific discourse. I think scientists are engaged in a healthy enough enterprise that eventually they will be able to sort out the uselessly vague concepts from the 'vague because they haven't been adequately understood and defined yet'.

    I do think there is a good deal of commonality among the reasonable comments about what emergence is and also feel the force of Eliezer's request for negative examples.

    I'll try to summarize (and of course over-simplify).

    When we have a large collection of interacting elements, and we can measure a property of the collection as a whole, in some cases we'd like to call that property emergent, and in some cases we wouldn't.

    I can think of three important cases:

    • If we can compute the property as a simple sum or average of properties of the individual elemen
    ... (read more)

    You do seem to be rising to the challenge. So here's the next questions:

    1) Is the property you've described objective or subjective? Are you talking about the thing itself, or a perspective you have on it?

    2) If subjective, does the perspective describe ignorance, or knowledge?

    3) You can define the set of left-handed red-haired Canadian women, but this set probably does not have any interesting properties that can be inferred from it beyond the definition itself. What can you infer once you say that something is emergent?

    Thanks, Eliezer. Regarding your questions:

    1. Is the property objective or subjective? The coarse grained property is objective -- e.g. the largest connected component in percolation. The meta-property that a coarse-grained property is emergent is as objective as the entropy of a configuration. It is model dependent, but in most cases we can't come up with a model that makes it go away.

    2. To the extent "emergentness" is subjective, it is because it is relative to a model. So in some cases it could possibly be the result of ignorance of a better mo
    3. ... (read more)

      Eliezer, although the comments did eventually get better, don't despair for the early comments on this post. Remember yourself, all you are finding in the comments is evidence confirming the belief that no one reading this blog is learning anything. I conjecture that those who have learned something just don't get excited enough to post because they don't disagree with you strongly enough or aren't sufficiently surprised to thank you publicly.

      Of course, I still suspect, as you probably do, from years of experience that most readers of this blog believe ... (read more)

      This thread appears to be missing references to support the notions that "emergence is commonly used as an explanation in its own right" and "many people think emergence is a useful concept, yet have different definitions of what it is".

      "Intelligence is an emergent phenomenon" is a valid response to Searle-followers - who ask questions about how brains can be intelligent when no neuron is intelligent. AFAIK, the response doesn't pretend to be a complete theory about how brains work.

      The word 'emergence' is an accent, not an explanation. It shifts focus to the idea that the system itself contains enough power or complexity to produce the effects wanted, when the mistake is to assume that the system doesn't have it. Let's show a simplistic example with ant colonies:

      Ant colonies exhibit intelligence.
      Ant colonies exhibit intelligent emergent behavior.

      In the first statement, there is an easily ambiguated idea that intelligence is part of the ant colonies. This could mean one of many possible things in common speech:
      - The ants themselves ... (read more)

      The example of emergence that comes to my mind most readily is a simple observation that Douglas Hofstadter made in Godel, Escher, Bach -- a book which definitely does not use "emergent" as a synonym for "magical":

      In a game of Go, once there are two separate open spaces -- "eyes" -- in the middle of a connected group of stones, that group becomes invincible (because the opponent can't fill both holes with one move). There's no official rule in Go that says "Patterns with two eyes can't be captured", the rule just sa... (read more)

      i think by 'emergence' you just mean 'implication'

      I just came from a debate with a friend of mine about emergence, so here's a simple example of what emergence is and isn't that I just told to him. (That he rejected anyway.)

      Let's take, as an example, a car. Motion is an emergent property in cars. (I'm talking about motion on the level we live on that allows whole objects to move great distances.)

      The pieces of the car, gathered into a pile, could not move. So motion was not a property in the parts making up the car. Motion emerges when the parts are built into the complex relationship that makes up the car... (read more)

      Most of this is specific to videogames and probably will not be applicable anywhere else:

      An emergent property in the context of videogames is one the designers of the game did not intend, [more strictly: yet is not a programming error].

      Excluding the possibly, since this example is ambiguous using it:

      In the game Super Smash Bros, jumping is not emergent, since the designers programmed it into the game specifically.

      Wavedashing [dodging into the ground so that you will be able to move while attacking] (and in fact, every single bit of strategy for every chara... (read more)

      What's the difference between a "programming error" and an "emergent consequence of the program as written", other than whether the programmers decide they like the result? Is it just a question of whether the rules involved can be described intuitively at the level of user-interface objects rather than lines of code?
      Answer to your question: Honestly, I should not have included that line about errors in there at all; it doesn't need to be special cased out because most errors are emergent. (Not always; a missing negative somewhere is not emergent. But when you get to the complexity of a video game, most errors that will make it through QA are emergent.) But also: I actually have thought about this a bit since I wrote this, and I think I can come up with a decent general definition for emergence: (don't worry, I'll get to your question in a moment) Something is emergent when it is caused by a rule that works similarly to the second law of thermodynamics. (More specifically, the property of the second law that it isn't actually a hard law at all; it's just that when you crunch all the probabilities for all the particles involved, it is vastly more likely that the result will obey the second law then will not.) Similarly, the ways economies develop aren't hard laws; it would be entirely possible for an economy to develop in such a way that it lets you get a free lunch. It's just that that, considering all the actors involved are out to find and take those free lunches, that you are about (using about very broadly here) as likely to find an actual free lunch as you are to find your foot has suddenly turned into gold. (Also: I think it's a mistake to point at some finished product of laws of emergence and say it's emergent. "The economy is emergent" is just a short and slightly misleading way to say "The laws that govern an economy are laws of emergence".) But going back to what this predicts: It predicts mainly that there is something equivalent to atoms in thermodynamics or actors in economics; some small unit of behavior that you can test for. It also predicts (in very complex systems it might not be possible to do any actual math on this, but in theory it predicts) how often the law will fail. (As noted, sometimes all you can say with confidence is "it might fail sometime";

      Eliezer apparently travels in different circles than I do, and encounters people who use the word "emergence" very differently. Here is the kind of situation where I usually hear the word "emergence" used:

      Me: Well, I think I'll build an AI that understands Chinese this weekend.

      Philosopher: Build it from what?

      Me: NAND gates, I suppose.

      Philosopher: That's impossible. Searle proved it. NAND gates don't understand Chinese, even a little. So a collection of lots of NAND gates can't understand Chinese either.

      Me: Huh? Searle and you don't get it. The understanding of Chinese is going to be an emergent property of the whole complex system.

      Philosopher: "Emergence! Aaarghh!"

      Me: Would you like me to explain the code to you?

      Philosopher: No, thanks. I don't know anything about programming. But I do know that the word "Emergence" is a sure sign of messed up thinking.

      In other words, I don't consider "emergence" as an inoculation against curiosity. I consider it an inoculation against stupidity. It is a claim by a reductionist that a high level phenomenon can be constructed from low-level machinery which is different in kind.


      ... (read more)

      You will have to forgive me, as i am over three years late to get here since inception, and about six months late since the last comment, but surely rationality waits for all. I seek the help of rationalists more advanced then me because something still seems very flawed with the argument when I account for my previous understanding of emergence. As I understood it, emergence most recently came about when psychology hit a serious recursive (is that the right word?) question, that is namely "where is consciousness located in the mind?". To fram... (read more)

      Again, please help me and let me know if I am wrong, badly wrong, or very badly wrong but a little right, but Eliezer's argument seems to suffer from a couple basic flaws, the use of replacing emergence with magic being the first. It certainly serves its point to draw the parallel's between the current use of emergence and magic, but i could just as easily say, A: The car moves because of (combustion being directed into useful kinetic energy that causes parts to move and the car to run) B: the car moves because of magic as you noted, magic fails to explain everything because it is so general, and so can be compared to anything, in which lies the fallacy. You could make your point about magic and anything just as easily because magic isn't a real explanation, nor is it a good comparative point for anything. and the other point i guess is one that every college freshman knows, "wikipedia is not a liget source of anything. dont use it" though i will say that the comparisons to an engine and go earlier do not serve the purpose of those who support the hypothesis that emergence is a legitimate concept because as I noted above, the individual pieces of an engine do posses the property of motion, the oil and the fire, should you heap all the pieces of a car in a pile atop a bucket of oil and apply fire you will find that each individual piece will gain the property of motion quite rapidly and in your general direction.

      You will have to forgive me, as i am over three years late to get here since inception, and about six months late since the last comment, but surely rationality waits for all. I seek the help of rationalists more advanced then me because something still seems very flawed with the argument when I account for my previous understanding of emergence. As I understood it, emergence most recently came about when psychology hit a serious recursive (is that the right word?) question, that is namely "where is consciousness located in the mind?". To fram... (read more)

      You use quarks as your one example of something that is not emergent. However, how can you prove that quarks are not a system of smaller interacting particles? String theory seems to propose that quarks can be broken into smaller pieces which are strings. Maybe its the interaction of the strings that cause the overall action of the quark?
      As for emergence, the way I understand Emergence based on this post and the comments is that emergence is a result of the parts of a system interacting with one another, possibly limited to those event that were not pre... (read more)

      This misses the point. 'Quarks' were a stand-in for whatever particle you take to be fundamental; if there's something smaller than quarks, that does not defeat the notion that it is unhelpful to describe the action of the stock market in terms of its non-quarkness. In what way is this a useful concept? In particular, having not been predicted is a feature of the predictor, not so much of the event, and so attaching the adjective to the event invites thinking wrongly that 'emergence' is fundamental to the event. It is not an ad hominem argument. I know that because you club baby seals and you claimed it was an ad hominem argument; therefore, it is not an ad hominem argument. The previous sentence is an example of an ad-hominem argument. There are of course other varieties of ad hominem, but it isn't any of those either. It is really not a non-sequitor. The point is that 'emergent' tells you about as much about the phenomenon as 'mysterious'. It doesn't communicate much more than "I don't understand why this happened" - as you grant above.
      Now that I have read more articles, I understand that most of my issues were due to taking the words with my definition and not hers. The result is that the article seems to be against those with different definitions of emergent, even though there is most likely more than one common definition of emergent, and no definition was previously selected as the correct one.
      For reference, the above article was written by this guy.

      Well, I agree that that fake explanation is used too often, and that it only gets any cred because it's from the right literature genre. But I don't think the whole of work in emergence can really be reduced to a mystery to worship. Certainly "emergence" is a stupid noun, just like "Red-hood" is a stupid noun. And that's a wonderful exercise to shut up the anti-reductionist movement based around emergence.

      But "emergently arising" and "arising" can be given useful different meanings without stretching things too far... (read more)

      that description fits every phenomenon in our universe above the level of individual quarks...

      What do you know, after you have said that intelligence is "emergent"? You can make no new predictions.

      It is true that I can make no new predictions, and you can make no new predictions, but other people do make new predictions from the explanation "emergence".

      "Emergence" is like "atheism" or "naturalism".

      If a religious person learns only that a set of phenomena is the world is explained by naturalism, that pe... (read more)

      The term "emergence" doesn't mean anything in and of itself, but it does mean something very particular when applied to specific systems. For example, one could say that oscillating patterns with a period of four generations and lateral motion of 1/2 cell per generation are an emergent phenomenon of cellular automata on a randomly filled square grid with 3/23 rules (gliders in Conway's game of life). You don't know whether any given cell is alive or dead, but it's a very good guess that given a modestly large board, there is a glider somewhere on that board. That's what I take "emergent phenomenon" to mean.

      I believe I first came across the term emergence in relation to Langton's Ant, in a book section loosely centered on game theory. In the book, the patterns formed by the progression of Langton's Ant were termed 'emergent' because they could not be predicted except by running the program. One could not, with full knowledge of the simple rules that governed the Ant's world, predict what the pattern would look like after x iterations, or where the ant would be. Given this, I would not call the location of a dropped object at time t after the drop an 'emergen... (read more)

      As Eliezer requested, I offer my view on what emergence isn't: emergence is not an explanation. When I say that a phenomenon is emergent, I am using a shorthand to say that I understand the basic rules, but I can't form even a simple model of how they result in the phenomenon.

      Take, for example, Langton's Ant. The ant crawls around on an infinite grid of black and white squares, turning right at the centre of each white square and left ant the centre of each black square, and flipping the colour of the square it's in each time it turns.

      The first few hundred steps create simple patterns that are often symmetric, but after that the patterns Langton's Ant produces become pseudorandom. If left to run for around 10000 steps, the Ant builds a highway - that is, it falls into a pattern of 104 of steps, and at the end of each cycle, it has moved diagonally and the cycle repeats. After millions of steps, the grid has a diagonal streak across it. As far as we know, the Ant always builds a highway.

      Highways are emergent by the definition I use - that is, I know exactly how Langton's Ant works, and therefore, in theory, know why it builds a highway, but I can't form a model of its behaviour t... (read more)

      I was under the impression that a property x was emergent if it wasn't determined by the set of property states of the components. IE, gravity isn't emergent since the gravity generated by something is the addition of the gravity of the parts. Intelligence isn't, because even if I know the intelligence of each of your neurons, I don't know your intelligence.

      Observation of individual neurons doesn't indicate they have intelligence however doe it means that intelligence of a human brain is emergence phenomenon? Observation of individual atoms and molecules wouldn't revel any gravitation like properties either however we don't call that gravity emergence phenomena. Instead we argue that gravitation like properties of atoms and molecules are not observable. Could you conceder that we may grossly underestimate an "intelligent ability" of individual neurons?
      What I meant by this is the gravitational influence of N particles is the sum of the gravitational influences of each of the individual particles, and is therefore a strict function of their individual gravitational influences. If you give me any collection of particles, and tell me nothing except their gravitational fields, I can tell you the gravitational field of the system of particles. If you tell me the intelligence of each of your neurons (0), I cannot determine your intelligence.

      An excellent example of a published paper against reductionism, using "emergence" in exactly this way such that it is indiscernible from "magic", is here:

      "Emergent" is just an adjective describing an attribute. Other examples are complex, simple, generic, unique, random, predictable, valuable, politically inconvenient, unexpected, widely-known, and a few others. For example, saying "The behavior of the ant colony is the widely-known outcome of the interactions of many individual ants.", won't tell you much new about the ant colony itself, nor will it let you model it. It will tell you that ant colonies aren't successfully secretive, nor too complex for humans to understand, which technic... (read more)

      I have always been intrigued that such a complex system like a living cell, could be reduced underlying physics and chemistry. Over time, my reductionistic curiosity was eroded by holistic views that embrace emergence phenomenon as an explanation of complexity. However, eventually, I was disillusioned with the emergence paradigm, as misleading and concluded that the popular interpretation of holism ‘The whole is more than the sum of its parts,’ is profoundly deceptive if used within scientific explanation. My current view is that emergence is a perception caused by part’s properties not observable in isolated parts. These properties become observable only during interactions in the system; a system acts as ‘litmus test’ or a ‘magnifying glass’ that just reveals the parts’ properties not observable otherwise. Regarding ant colony how much we know about individual ants to deprive them from ability of complex behavior? In my book the complexity of any system resulted from collective complexity of its elements. The typical rhetorical argument in favor of emergence is the question: ‘Is water more than one atom of oxygen and two atoms of hydrogen?’ The intuitive respond, is yes, because in our perception, water, the way we directly experience it, is very different from an abstract theoretical model of atoms of oxygen and hydrogen. However, from a scientific point of view this question is misleading. The correct question would be: ‘Is a molecule of water more than one atom of oxygen and two atoms of hydrogen, interacting among each other?’ This time the answer is no: the molecule of water is no more that the sum of its components. I would be interested in any example in which complexity of the system "emerges" from elements we know (or at least we believe we know) everything about.
      If anything, a single ant is a far more complex system than, say, a simple simulation of an ant colony of a computer.
      In this case it is obvious. However, in general a system could be less complex than complexity of its elements. We don't have agreeable way to measure complexity but for now I would argue that complexity of molecule of water (its complete physical and chemical description) is more complex than sum of those molecules in form of a drop of water. Unfortunately so far there's neither accepted approach to measure nor define complexity.

      I would suggest reading "More is Different", an excellent paper on the topic of emergent phenomena and the limits of reductionism. (

      The "More is Different" approach essentially notes that even when the basic bottom-up rules are known, they cannot be efficiently used to predict large-scale interactions. Those behaviours have to be studied as though they have their own set of rules (ie, the laws of chemistry), even though they emerge from a more fundamental... (read more)

      In summary: emergence is sometimes an observation but never an explanation.

      6Max Hodges
      not exactly. I'm fond of @ryleah's contribution: "Emergence as a term doesn't add a reason for a thing, but it does rule some out."
      Of course. Emergence and reduction are types of explanation, not explanations themselves.

      Whilst I appreciate the validity of criticism offered here of the use of the word emergence (by itself) as if were an explanation sufficient unto itself - I think it a little harsh. To call it "futile" is almost acting as semantic stop sign itself for the term.

      We need to take a little time to properly understand what is meant by emergence when used properly.

      First that it is an observation rather than an explnation. But an observation with useful descriptive power since it observes that the phenomena under consideration is a process with properti... (read more)

      Wolfram has done a lot of fantastic work on emergent mathematical phenomena. (TED talk given to a non-technical audience, but still worth watching.) One of the highly counter-intuitive things that he has worked on is computational irreducibility. Irreducible functions are ones where you have to physically run the function to find it's outcomes, and the emerging patterns. For this class of function, the emergent patterns cannot be predicted in advance.

      There seems like the next step to build on older work on the halting problem, which states that some types ... (read more)

      This is very curious. I never thought of emergent as an explanation but as a property. I roughly understood it to mean that the emergent quality was transferable. That is, intelligence is a product of neurons firing but it need not have been, it could also have been generated from transistors or whatever else.

      This is roughly the opposite of your ant example. Something is emergent if it can be explained/predicted with no knowledge of the lower level. A lot of properties of turing machines do not depend on the actual formalism of the turing machine.

      Edit: After browsing the other comments, I realize this is something that has been brought up before. My 2 cents for whatever it is worth, I guess...

      An important point that I think this raises is that answers which are otherwise not mysterious can be made mysterious if they are used as such. One good example is the way that some laypeople use "quantum mechanics" interchangeably with "magic". This doesn't invalidate quantum mechanics in its correct usage. The same could be said of emergence, which, given the comments below, seems to at least be disputed as a mysterious answer in and of itself.

      EDIT: Also, this is my first post (reading through the Sequences, getting acquainted with the basics, etc.), so feedback is appreciated. I hope my contribution, well, contributes!

      This is the species that thought lightning had a personality. We need a word for things happening for a bunch of tiny, seemingly unrelated reasons.

      [This comment is no longer endorsed by its author]Reply

      "Intelligence is an emergent phenomenon!" means that intelligence didn't happen on purpose, or that intelligence doesn't need to be intentional in order to happen. Emergence as a term doesn't add a reason for a thing, but it does rule some out.

      1Max Hodges
      beautifully stated!

      You can also add the adjective 'emergent' into any sentence, and the product will be comparative garbage.

      Saying "X is emergent" is conveying some information, if there is someone in the room that does not already know this fact. Here is an example:

      Quarks are emergent.

      This is not an explanation though. It is more like a anti-explanation. I just claimed that there is an underlying explanation to quarks, and then stopped. I told you to make space for an explanation, in you mental world model, and then I left you with that space empty. If you believed my statement, and if you don't already know how quarks emerges and from what, I just made an explanatio... (read more)

      Is it ok to still post a question here? (I only discovered this blog recently. Not sure if anyone will see this.) Accepting that "emergence" is the wrong term, could someone tell me the right term for what I thought emergence referred to?

      Someone mentioned water. Even if we knew a lot (everything?) about hydrogen and oxygen atoms, we would not be able to deduce fluid dynamics. There is something about water -- it's properties and behaviors -- that isn't reducible to its constituent parts in isolation, right? Scientific reductioni... (read more)

      Totally fine to ask questions on old posts (they actually show up on the frontpage) I think the point here was "it's fine to describe things as emergent when that's applicable – but it's not an explanation that helps narrow down what's going on. If it's your only explanation, you can't really distinguish between emergent things that work one way and ones that work another way. In the case of water, if you want to understand it (at the level that'd let you predict which other materials might have similar properties), you need to know something in addition to the fact that it's "emergent."

      I thought “emergence” talked about properties of a system which could not be localized to any of its parts.

      It's possible that the notion of "emergence" arose as a reaction to a hard-core positivist view that there is no way for us to understand, say, biology, until we can deduce it from the behavior of individual quarks. So, possibly, the notion of "emergence" may have been invented just to say that it's actually ok to study biology even if you don't entirely understand how quarks combine into a mitochondrion. The fact that you don't have a perfect a model of how quarks lead to a mitochondrion does not forbid you to study... (read more)

      "Emergence" isn't a label for a single concept that is one hundred percent wrong, it can refer to a variety of positions of differing plausibility. Weak emergence is just the claim that systems have properties that their parts don't have. That's obviously true in many cases: a watch can tell the time, a single cog in the machine cannot. Strong emergence is a claim along the lines that some properties of a system cannot be understood in terms of its parts and interactions -- the negation of the typical reductionist claim that it can be so understood. But there is a hefty catch in the clause about interactions. What would a strongly emergent system look like? You would have to understand it as a whole. Which is to say, even at the level of the parts, you would have to consider all the parts and all their interactions. Which means that to be distinct from emergence, reductionism needs to be more specific about interactions. (And note that without a clean distinction between emergence and reduction, there isn't much point in heated rhetoric about the evils of "magical" emergence). If a watch contains 10 cogs ,you would not expect each cog to interact with all the others. That kind of simplification is the advantage of reductive explanation. But not all systems are so convenient. At the quantum level, it is possible for every particle in a system to be entangled with every other. So we don't live in the most convenient of all possible universes for reductionism, even if we also don't live in the most inconvenient. There is a fundamental layer as required by reductionism, but it does not operate according to local determinism,as also expected. And there is a layer that can operate according to local determinism, the classical world, but it isn't the fundamental layer.
      1[comment deleted]

      Unmitigated reductionism has had a detrimental effect on drug discovery and vaccine development

      We simply can't anticipate or compute some interactions and effects due to the sheer complexity of living organisms in thermodynamic interaction with their environment. For instance, the experience of pain can alter human behaviour, but the lower-level chemical reactions in the neurons that are involved in the perception of pain are not the cause of the altered behaviour, as the pain itself has causal efficacy. According to the principles of emergence, the n... (read more)

      I think you're missing the point. To say, "life emerges from the activities of cells" or that "intelligence emerges from non-intelligence" is not simply to make empty statements devoid of meaning. The first is an assertions that "life" isn't a *thing* which one should seek to find somewhere, materially, in nature--like some yet-to-be-cataloged bird of paradise. It's a property of complex cellular processes. There are people who think that brain contains a "core self," as if it were a kind of organ. It ... (read more)

      "Taken literally, that description fits every phenomenon in our universe above the level of individual quarks, which is part of the problem."

      Is it a good description then? I can't even find the quote you use from Wikipedia (not exactly a top notch citation in the first place). That certainly doesn't seem like a good description at all. It doesn't really even describe what emergence theorists talk about. If your entire point is going to hinge on one description, maybe shop around for a good one. Just saying.

      "Now suppose I should say that gravity depends on ... (read more)

      This is so refreshing to read. I've been bothered by the "emergent phenomenon" hand waving for a while, and this post does a really satisfying job of explaining what is wrong with the term and its blind usage.