I have distrusted anyone using the term ’emergent property’. Now I have to abandon that prejudice. This doesn’t mean I intend to use ’emergent’ in my own thinking but just that I will be more open-minded to others using it. I was prompted to re-think this by a post on Less Wrong, (here). Eliezer Yudowsky slamed the use of the term and many people came its defence. Here is EY’s take on the word:
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.
…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.
…”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 still the same species psychology.
This is pretty much how I saw the word. But more importantly I thought I saw some intellectual dishonesty when I word was used. It seemed that the speaker was saying – I don’t want to discuss the explanation and I don’t want to appear to be a creationist, but the explanation includes God in a small but important way. Why would they use such a vague explanation if they were not hiding their thinking from us?
It turns out from the comments that many people use the term for the exactly opposite reasons. They are saying – I cannot give an explanation (don’t know it or its too complicated) but I assure you that I don’t think it includes anything super-natural. They are not giving an explanation but saying what type of explanation they think would do. Here are a few of the comments:
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.
“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”.
So emergence, in this sense, means that a phenomenon has many intertwined causes, rather than one or two identifiable and major causes.
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.
The general idea of emergence is primarily useful is in pointing out that when we don’t understand something, there are still alternative explanations to those that superstitiously posit a near-omniscience or that pretend to have information or an ability to model complex phenomena that one does not in fact have.
My own feeling is that many users of the term are groping for a clear definition of this general sort, and that they are doing so precisely to avoid having to explain a large class of phenomena by “magic”.
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.
I recommend reading the post and its comments in full for many other interesting ideas. I have cherry picked the ones that apply to my specific problem with the word. I now see the word as having two distinct and almost opposite meanings and therefore will not be using it as a guide to understanding what is being said.