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 says that to capture a group you have to surround it completely and leave no open spaces. Thus two-eye invincibility is an emergent consequence of the rules of Go.
It's important that this new emergent rule is a significant simplification: once you realize that two eyes are invincible, you no longer have to do any complicated analysis about how close a two-eyed group is to being completely surrounded. It's safe, full stop (at least as long as you don't stupidly fill in the holes yourself).
The game of Go has very few rules. In practice, the two-eye invincibility "rule" is a very important and useful one, if you want to play the game well. To try to force Eliezer to talk about "emergence" or something equivalent, I would ask: where did the two-eye invincibility rule come from?
-- Okay, now, so what isn't emergent? There's a another Go rule, the "ko" rule, which says you can't play in such a way as to get the exact same board position back after two moves: no capture followed by immediate recapture unless it changes the board. There's nothing "emergent" about that rule that I can think of -- it helps keep Go games from going on forever, but it has no simple-but-unexpected high-level consequences.
There are a lot of strategic patterns of play in Go that are not emergent, either -- e.g., there are no simple rules of thumb that can tell you, in all cases, whether a group with one eye or no eyes can be captured or not. Often the answer depends on a single apparently unrelated stone way over on the other side of the board. No simplifications available here, therefore no emergence.
There are many other more involved examples of emergence (and non-emergence) -- gliders and spaceships in Conway's Game of Life come to mind, and Herschels and random ash densities -- but this blog comment is too narrow to contain a good summary of them all...
Two other books that do a fine job (in my opinion) of describing the concept of "emergence" as distinct from "magic" are Cohen and Stewart's The Collapse of Chaos and Figments of Reality.
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:
Another fun exercise is to replace the word “emergent” with the old word, the explanation that people had to use before emergence was invented:
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.