Emergence is the phenomenon of complex systems emerging from the interaction of simpler parts. For example, chemistry emerges from the interactions of atoms bonding with each other to form molecules with properties quite distinct from the elements themselves. So it is often said that chemistry is reduced to physics. Extending this idea to the life sciences and humanities leads to radical reductionism, the claim that we and all around us is merely material. People are generally uncomfortable with such a bald assertion, and emergentism has developed as an alternative to reductionism, a way to get "something more from nothing but," in the favorite summary phrase of some advocates. Their hope is for a significant human reality emerging from nature.
This short essay is to organize my thoughts on emergence, to
prepare for a meeting of the Science & Religion Discussion Group that I
For those new to the topic of emergence, I will review some
of the material from the
Many writers propose different ways to categorize emergence, and a common distinction that seems clearest to me is just two categories, weak and strong. The Wikipedia entry on Weak_emergence is straightforward: "Weak Emergence is a type of emergence in which the emergent property is reducible to its individual constituents. This is opposed to strong emergence, in which the emergent property is irreducible to its individual constituents." Weak emergence is also called reductive or mundane emergence, and it's hard to find philosophical objections to it. Strong emergence is associated with ontological emergence, the more controversial claim that qualitatively distinct, significant new entities emerge at a higher level of existence. Emergence promises an escape from the nihilistic implications of reductionist materialism. It offers a kinder, gentler approach, not atheism but non-theistic religious naturalism. Advocates often discuss wonderful examples of (weakly) emergent phenomena, from mathematics through physics and chemistry to biology and psychology, with the suggestion if not the outright claim that our conscious mind emerges in this way, but that nevertheless we can take ourselves seriously and have compelling reasons to act morally and be hopeful.
At the Zygon conference, physicist Leo Kadanoff presented a very nice example of emergence of turbulence in the flow of a computationally simulated gas, described as a "square dance." An earlier published version of his talk is online at http://www.uchicago.edu/docs/education/record/pdfs/35-4.pdf. The basic rules of the kinetic theory of gases, the conservation of mass and momentum, were embodied as simulated particles on a hexagonal grid, with two moves, "promenade" (move forward one step) and "swing your partner" (two or three particles at one location make one sixth of a full-circle turn, but only if their momenta add to zero). Computers are a powerful tool for exploring complex phenomena, and provide impressive illustrations of chaotic and complex interaction. But he didn't want to comment on the significance of this sort of emergence for philosophy and religion.
A physicist more eager to interpret the meaning of physical emergence was Heinz Pagels, who died in a mountain climbing accident eerily like one he described dreaming about in his 1982 book The Cosmic Code: Quantum Physics as the Language of Nature. In chapter 13 of Part I he imagines a Reality Marketplace where representatives of different interpretations of quantum mechanics sell their stories. He concludes with a smoky vision of emergence: "We feel excited by his [Bohr's imagined] remarks, though the old uneasiness has not left us. Yet listening to him is certainly better than that marketplace. After a long silence our old friend gives us his final words. 'What quantum reality is, is the reality marketplace. The house of a God that plays dice has many rooms. We can live in only one room at a time, but it is the whole house that is reality.' He gets up and leaves us. Only the smoke from his pipe remains, and then, like the smile of the Cheshire cat, that too disappears."
This was the title of a presentation at the Zygon conference by Anne Foerst, a professor of computer science. She talked mostly about her work at MIT on people's interactions with a humanoid robot called Kismet (see http://www.ai.mit.edu/projects/humanoid-robotics-group/kismet/kismet.html), but she began by talking about the book that got her excited about AI as a student: Douglas R. Hofstadter's Gödel, Escher, Bach: an Eternal Golden Braid, a book that I too had eagerly read when it was first published in 1979. The theme of the book is self reference and the complexities that emerge from it. Hofstadter uses metaphorical dialogs to portray his ideas, and I think my "smoke and mirrors" characterization of emergence grew out of some of his imagery, like this :
Achilles: Well, it seems to me that this stuff with screens within screens is
interesting, but I'd like to get a picture of the TV camera AND the
screen, ON the screen. Only then would I really have made the system
engulf itself. For the screen is only PART of the total system.
Crab: I see what you mean. Perhaps with this mirror, you can achieve the
effect you want.
(The Crab hands him a mirror, and Achilles maneuvers the mirror and
camera in such a way that the camera and the screen are both pictured on
Achilles: There! I've created a TOTAL self-engulfing!
Crab: It seems to me you only have the front of the mirror-what about
its back? If it weren't for the back of the mirror, it wouldn't be
reflective-and you wouldn't have the camera in the picture.
Achilles: You're right. But to show both the front and back of this mirror,
I need a second mirror.
Crab: But then you'll need to show the back of that mirror, too. And what
about including the back of the television, as well as its front? And then
there's the electric cord, and the inside of the television, and-
Achilles: Whoa, whoa! My head's beginning to spin! I can see that this
"total self-engulfing project" is going to pose a wee bit of a problem.
I'm feeling a little dizzy.
Crab: I know exactly how you feel. Why don't you sit down here and take
your mind off all this self-engulfing? Relax! Look at my paintings, and
you'll calm down.
(Achilles lies down, and sighs.)
Oh-perhaps my pipe smoke is bothering you? Here, I'll put my pipe
away. (Takes the pipe from his mouth, and carefully places it above some
written words in another Magritte painting.) There! Feeling any better?
Achilles: I'm still a little woozy. (Points at the Magritte.) That's an interesting
painting. I like the way it's framed, especially the shiny inlay inside the
Crab: Thank you. I had it specially done-it's a gold lining.
Achilles: A gold lining? What next? What are those words below the pipe?
They aren't in English, are they?
Crab: No, they are in French. They say, "Ceci n'est pas une pipe." That
means, "This is not a pipe". Which is perfectly true.
Achilles: But it IS a pipe! You were just smoking it!
Crab: Oh, you misunderstand the phrase, I believe. The word "ceci" refers
to the painting, not to the pipe. Of course the pipe is a pipe. But a
painting is not a pipe.
Achilles: I wonder if that "ceci" inside the painting refers to the WHOLE
painting, or just to the pipe inside the painting. Oh, my gracious! That
would be ANOTHER self-engulfing! I'm not feeling at all well, Mr. Crab.
I think I'm going to be sick . . .
Hofstadter builds these ideas toward the emergent "Crux of Consciousness:" 
What might such [intrinsically] high-level concepts be? It has been proposed for eons, by various holistically or "soulistically" inclined scientists and humanists, that consciousness is a phenomenon that escapes explanation in terms of brain-components; so here is a candidate, at least. There is also the ever-puzzling notion of free will. So perhaps these qualities could be "emergent" in the sense of requiring explanations which cannot be furnished by the physiology alone. But it is important to realize that if we are being guided by Gödel's proof in making such a bold hypotheses, we must carry the analogy through thoroughly. In particular, it is vital to recall that G's nontheormhood does have an explanation -- it is not a total mystery! The explanation hinges on understanding not just one level at a time, but the way in which one level mirrors its metalevel, and the consequences of this mirroring. If our analogy is to hold, then, "emergent" phenomena would become explicable in terms of a relationship between different levels in mental systems.
. . .
My belief is that the explanations of "emergent" phenomena in our brains -- for instance, ideas, hopes, images, analogies, and finally consciousness and free will -- are based on a kind of Strange Loop, an interaction between levels in which the top level reaches back down towards the bottom level and influences it, while at the same time being itself determined by the bottom level.
. . .
This should not be taken as an antireductionist position. It just implies that a reductionist explanation of a mind, in order to be comprehensible, must bring in "soft" concepts such as levels, mappings, and meanings. In particular, I have no doubt that a totally reductionist but incomprehensible explanation of the brain exists; the problem is how to translate it into a language we ourselves can fathom.
Relating this to weak or strong emergence, I think Hofstadter is saying that there is only weak emergence, but it is incomprehensibly complex. To comprehend ourselves, we must work with "soft" concepts which appear as "strong" emergence. But this seems paradoxical to me -- if the weakly emergent theory of our mind is true, then we are merely a complex arrangement of particles and no one is really there to bring in concepts or to comprehend anything. Strong emergence seems to be necessary to even discuss such a theory of mind, but where does it come from? How can it emerge from the reductionist straitjacket of weak emergence? Hofstadter's use of smoke and mirrors imagery suggests that whatever reality we have emerges by a partially obscure (smoky) process of compounded self-reference (mirroring).
Emergence as an explanation of our minds and ourselves relates to classic issues of philosophy. Realism is practically necessary for science, although actual scientists usually prefer not to dwell on philosophy and get on with their work. But realism carried through to a reductionist theory of mind as described by Hofstadter doesn't include the reality of ourselves. Idealism and dualism are philosophically problematic as well. Emergence seems to offer a plausible way to get from fundamental physics to higher level phenomena like brains and minds while remaining grounded in reality.
Philosopher Carl Gillett of
Antje Jackelén and Phil Hefner gave the concluding
presentations at the Zygon conference, on emergence and theology. Jackelén succeeded Hefner as Director of the
Emergence is a prominent topic in science and religion. It is widely seen as a hopeful path to rescue
significance from the jaws of reductionism, especially by advocates of
religious naturalism, both nontheistic and theistic. Nontheistic thinkers see emergence as a way
to get "something more from nothing but." I am skeptical of nothing butters, and see
more smoke and mirrors than enlightenment.
But I think those within Christian and Jewish faiths should not reject
emergence, but affirm it as a way to understand the revelation of God. And I don't just intend smoke and mirrors as
a pejorative, recalling the words of
1. Douglas R. Hofstadter, Gödel, Escher, Bach: an Eternal Golden Braid, 1979, Basic Books. The dialog between Achilles and the Crab is from the section in Chapter XV on Edifying Thoughts of a Tobacco Smoker. Only the last few paragraphs. Only the last few paragraphs are quoted here, in my original edition on pp. 493-494.
2. ibid, from Chapter XX, the sections on "Consciousness as an Intrinsically High-Level Phenomenon" and "Strange Loops as the Crux of Consciousness", in my original edition on pp. 708-709.
3. 1 Corinthians 13:9-13, Holy Bible RSV.