Talk:Emergence/References

The following references were collected by several editors during collaboration on an improved version of the article. Please add any more which may be relevant. - Fourdee 07:04, 17 December 2006 (UTC)

From Crutchfield, James P. (1994), "The Calculi of Emergence: Computation, Dynamics, and Induction" (PDF), Physica D, Special issue on the Proceedings of the Oji International Seminar: Complex Systems — from Complex Dynamics to Artificial Reality:

Definition:

"Emergence is generally understood to be a process that leads to the appearance of structure not directly described by the defining constraints and instantaneous forces that control a system. Over time “something new” appears at scales not directly specified by the equations of motion. An emergent feature also cannot be explicitly represented in the initial and boundary conditions. In short, a feature emerges when the underlying system puts some effort into its creation."

The non-objectivity of emergence:

"Defining structure and detecting the emergence of complexity in nature are inherently subjective, though essential, scientific activities. Despite the difficulties, these problems can be analyzed in terms of how model-building observers infer from measurements the computational capabilities embedded in nonlinear processes. An observer’s notion of what is ordered, what is random, and what is complex in its environment depends directly on its computational resources: the amount of raw measurement data, of memory, and of time available for estimation and inference. The discovery of structure in an environment depends more critically and subtlely, though, on how those resources are organized. The descriptive power of the observer’s chosen (or implicit) computational model class, for example, can be an overwhelming determinant in finding regularity in data."

Lack of refutation of determinism:

"One recent and initially baffling example of emergence is deterministic chaos. In this, deterministic equations of motion lead over time to apparently unpredictable behavior. When confronted with chaos, one question immediately demands an answer — Where in the determinism did the randomness come from? The answer is that the effective dynamic, which maps from initial conditions to states at a later time, becomes so complicated that an observer can neither measure the system accurately enough nor compute with sufficient power to predict the future behavior when given an initial condition. The emergence of disorder here is the product of both the complicated behavior of nonlinear dynamical systems and the limitations of the observer."

From Corning, Peter A. (2002), "The Re-Emergence of "Emergence": A Venerable Concept in Search of a Theory" (PDF), Complexity, 7(6): 18–30:

Definition:

"Perhaps the most elaborate recent definition of emergence was provided by Jeffrey Goldstein in the inaugural issue of Emergence.(Goldstein 1999) To Goldstein, emergence refers to "the arising of novel and coherent structures, patterns and properties during the process of self-organization in complex systems." The common characteristics are: (1)radical novelty(features not previously observed in systems); (2)coherence or correlation (meaning integrated wholes that maintain themselves over some period of time); (3) A global or macro "level" (i.e. there is some property of "wholeness"); (4) it is the product of a dynamical process (it evolves); and (5) it is "ostensive" - it can be perceived. For good measure, Goldstein throws in supervenience -- downward causation." (Corning 2002)

Objectivity:

"Must the synergies be perceived/observed in order to qualify as emergent effects, as some theorists claim? Most emphatically not. The synergies associated with emergence are real and measurable, even if nobody is there to observe them."

"The ability to reduce everything to simple fundamental laws does not imply the ability to start from those laws and reconstruct the universe..The constructionist hypothesis breaks down when confronted with the twin difficulties of scale and complexity..At each level of complexity entirely new properties appear..Psychology is not applied biology, nor is biology applied chemistry..We can now see that the whole becomes not merely more, but very different from the sum of its parts."(Anderson 1972)

"Every resultant is either a sum or a difference of the cooperant forces; their sum, when their directions are the same -- their difference, when their directions are contrary. Further, every resultant is clearly traceable in its components, because these are homogeneous and commensurable. It is otherwise with emergents, when, instead of adding measurable motion to measurable motion, or things of one kind to other individuals of their kind, there is a co-operation of things of unlike kinds. The emergent is unlike its components in so far as these are incommensurable, and it cannot be reduced to their sum or their difference." (Lewes & 1874-1879)(Blitz 1992)

Hofstadter supports only "weak emergence" in explaining consciousness, from GEB:

"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."

Gell-Mann on the subject of consciousness rejects the mystical, new-cause and pseudo-Heisenberg-based explanations - from the summary of "Consciousness, Reduction, and Emergence":

"Consciousness is often seen as requiring a special kind of explanation. But the various aspects of self-awareness can presumably emerge when certain levels of complexity are reached in an organism: it is not necessary to assume additional mechanisms or hidden causes. Looking at the most fundamental level, that of elementary particle physics, three principles appear—the conformability of nature to herself, the applicability of the criterion of simplicity, and the utility of certain parts of mathematics in describing physical reality—which are in themselves emergent properties of the fundamental laws of physics. [...] All the other sciences emerge in principle from fundamental physics plus historical accidents, even though "reduction" is obviously inadequate as a strategy. [...] Finally, it is argued that appeals to the alleged weirdness of quantum mechanics are based on a misunderstanding and are unlikely to have any place in a discussion of consciousness."

Perpetuating Evolutionary Emergence" by Alastair Channon:

"Cariani identified the three current tracts of thought on emergence, calling them “computational”, “thermodynamic” and “relative to a model”. Computational emergence is related to the manifestation of new global forms, such as flocking behavior and chaos, from local interactions. Thermodynamic emergence is concerned with issues such as the origins of life, where order emerges from noise. The emergence relative to a model concept deals with situations where observers need to change their model in order to keep up with a system’s behavior. This is close to Steels’ concept of emergence, which refers to ongoing processes which produce results invoking vocabulary not previously involved in the description of the system’s inner components – "new descriptive categories"."

David J. Chalmers paper on Weak vs. Strong emergence at [1]:

"Since [strongly] emergent phenomena supervene on underlying processes, in this sense the underlying processes constitute and generate the emergent phenomena. And emergent phenomena are autonomous from the underlying processes since they exert an irreducible form of downward causal influence. Nevertheless, strong emergence has a number of failings, all of which can be traced to strong downward causation.:

"Although strong emergence is logically possible, it is uncomfortably like magic. How does an irreducible but supervenient downward causal power arise, since by definition it cannot be due to the aggregation of the micro-level potentialities? Such causal powers would be quite unlike anything within our scientific ken. This not only indicates how they will discomfort reasonable forms of materialism. Their mysteriousness will only heighten the traditional worry that emergence entails illegitimately getting something from nothing."

David Blitz stated that the term 'emergent' was coined by the pioneer psychologist G. H. Lewes in his multi-volume "Problems of Life and Mind"(1874-1879).

"Every resultant is either a sum or a difference of the cooperant forces; their sum, when their directions are the same -- their difference, when their directions are contrary. Further, every resultant is clearly traceable in its components, because these are homogeneous and commensurable..It is otherwise with emergents, when, instead of adding measurable motion to measurable motion, or things of one kind to other individuals of their kind, there is a co-operation of things of unlike kinds..The emergent is unlike its components in so far as these are incommensurable, and it cannot be reduced to their sun or their difference"

John Stuart Mill on emergence, "The chemical combination of two substances produces, as is well known, a third substance with properties different from those of either of the two substances seperately, or of both of them taken together"

Aristotle in what is now the text called _Metaphysics_ "The whole is something over and above its parts, and not just the sum of them all.." .

Joseph Needham "the existence of [different] levels of organization in the universe, successive forms of order in a scale of complexity and organization"

Julian Huxley "now and again there is a sudden rapid passage to a totally new and more comprehensive type of order or organization, with quite new emergent properties, and involving quite new methods of further evolution"

Stuart Kauffman - life is a "spontaneous crystallization" and "the whole is greater than the sum of its parts"

"John Casti, like Lewes and Morgan, associates emergence with dynamic systems whose behavior arises from the interaction among its parts and cannot be predicted from knowledge about the parts in isolation."[41]

John Holland "much coming from little" and imposes the criterion that it must be the product of self-organization, not centralized control

"Perhaps the most elaborate recent definition of emergence was provided by Jeffrey Goldstein in the inaugural issue of Emergence[46] 'the arising of novel and coherent structures, patterns and properties during the process of self-organization in complex systems' The common characteristics are: (1)radical novelty(features not previously observed in systems); (2)coherence or correlation (meaning integrated wholes that maintain themselves over some period of time); (3) A global or macro "level" (i.e. there is some property of "wholeness"); (4) it is the product of a dynamical process (it evolves); and (5) it is "ostensive" - it can be perceived. For good measure, Goldstein throws in supervenience -- downward causation."

Jeffrey Goldstein "emergence functions not so much as an explanation but rather as a descriptive term pointing to the patterns, structures or properties that are exhibited on the macro-scale"

Michael Lissack, "[Emergence] is less than an organized, rigorous theory than a collection of ideas that have in common the notion that within dynamic patterns there may be underlying simplicity that can, in part, be discovered through large quantities of computer power..and through analytical, logical, and conceptual developments.."

"I would propose that emergent phenomena be defined as a "subset" of the vast (and still expanding) universe of cooperative interactions that produce synergistic effects of various kinds, both in nature and human societies. In this definition, emergence would be confined to those synergistic wholes that are composed of "unlike kinds" (following Lewes' original definition). It would also be limited to "qualitative novelties" (after both Lewes and Lloyd Morgan) -- i.e. unique synergistic effects that are generated by functional complementarities, or a combination of labor. In this more limited definition, all emergent phenomena produce synergistic effects, but many synergies do not entail emergence. In other words, emergent effects would be associated specifically with contexts in which constituent parts with different properties are modified, re-shaped or transformed by their participation in the whole."

"Must the synergies be perceived/observed in order to qualify as emergent effects, as some theorists claim? Most emphatically not. The synergies associated with emergence are real and measurable, even if nobody is there to observe them. And what about the claim that emergent effects can only be the result of "self-organization"? Is this a requirement? Again, emphatically not. Self-organizaton is another academic buzzword these days that is often used uncritically."

"John Maynard Smith points out, there is a fundamental distinction between self-organizing processes (or, more precisely, what should be called "self-ordering" processes) and wholes that are products of 'functional organization' (as in organ systems)."[62]

"the debate about whether or not the whole can be predicted from the properties of the parts misses the point. Wholes produce unique combined effects, but many of these effects may be co-determined by the context and the interactions between the whole and its environment(s)."

"In its 19th and early 20th century incarnation, reductionism meant an understanding of the "parts" -- period. Modern-day reductionists, by contrast, speak of the parts 'and' their "interactions". But the "interactions" among the parts (and between the parts and their environment) 'are' "the system". The "whole" is not something that floats on top of it all. So this cannot properly be called reductionism; it is "systems science" in disguise. Indeed, the interactions among the parts may be far more important to the understanding of how a system works than the nature of the parts alone."

Phillip Anderson , "The ability to reduce everything to simple fundamental laws does not imply the ability to start from those laws and reconstruct the universe..The constructionist hypothesis breaks down when confronted with the twin difficulties of scale and complexity..At each level of complexity entirely new properties appear..Psychology is not applied biology, nor is biology applied chemistry..We can now see that the whole becomes not merely more, but very different from the sum of its parts."

Arthur Koestler used the metaphor of Janus to convey the idea that both reductionism and holism are essential to a full understanding of living systems - emergence is neither a mystical concept nor is it a threat to reductionist science."It is the synergistic effects produced by wholes that are the very cause of the evolution of complexity in nature."