Part 5 (1/2)

EMERGENCE.

. . . we need an account of the material world in which it isn't absurd to claim that it produced us.

-TRANSLATED AND REPHRASED BY THE AUTHOR FROM ILYA PRIGOGINE AND ISABELLA STENGERS, 1979.

NOVELTY.

Whereas the formation of the first stars, the formation of the nuclei of the first heavier-than-hydrogen elements, the coalescence of atoms into the first molecules, and so on, have each had a profound effect on the interactions and distributions of substances in the universe, a common set of physical equations is able to give a reasonably complete description of the properties that resulted. The same cannot be said of the transitions that led to life and to mind. Though the laws of physics and chemistry were not violated or superseded in these transitions, their appearance led to a fundamental reorganization in how these properties were expressed and distributed in the world and how they were organized with respect to each other. The reliable reversal of typical thermodynamic tendencies, and the insinuation of informational relations.h.i.+ps into the causal dynamics of the world, make the transitions from inorganic chemistry to life, and from mechanism to thought, seem like radical contraventions of causality-as-usual. So, although I am convinced that no tinkering with basic physics is required to make sense of these phenomena, we still need to account for the radical about-face in how these principles apply to everyday ententional phenomena. At some point, the reliable one-dimensional lockstep of just one thing after another that had exclusively characterized physical events throughout the universe took an abrupt turn and headed the other way.

The appearance of the first particles, the first atoms, the first stars, the first planets, and so on, marked fundamental new epochs in the 13-billion-year history of the universe, yet none of these cosmic transitions contorted the causal fabric of things as radically as did the appearance of life or of mind. Even though these living transitions only took place on a comparatively insignificant scale compared to other cosmic transitions, and even though no new kind of matter or energy came into existence with them, what they lack in scale and cosmic effect they make up in their organizational divergence from the universal norm. Consider the following: * There were no ententional properties in the universe for most of its 13-billion-year history (i.e., before significant amounts of heavier elements were produced by dying stars).

* There was nothing resembling a function on the Earth until just over 3 billion years ago, when life first appeared.

* There was no hint of mental awareness on Earth until just a few hundred million years ago, when animals with brains first evolved.

* There was nothing that was considered right or wrong, valuable or worthless, good or evil on our planet until the first human ancestors began thinking in symbols.

All these innovative ways of organizing matter and energy, producing unique forms of influence over the events of the world, popped into existence from antecedent forms of organization that entirely lacked such properties. Physics and chemistry continued as they had before, but radical and unprecedented changes in the way materials and events could become organized followed these transitions wherever and whenever they occurred.

Such major transitions in the organization of things are often described as emergent, because they have the appearance of spontaneous novelty, as though they are poking their noses into our world from out of a cave of non-existence. And while they are not exactly something coming from nothing, they have a quality of unprecedented discontinuity about them-an almost magical aspect, like a rabbit pulled from an apparently empty hat.

In the way the term is often used, there is a close kins.h.i.+p between the concept of emergence and ideas of novelty and newness, as well as an implication that predictability is somehow thwarted. Although I hope to show how these are misleading attributions, this view is both common and attractive. For example, one of the more widely read books on emergence, written by the eminent physical chemist Harold Morowitz, itemizes and describes over twenty ”emergences” in the history of the cosmos, including everything from the formation of stars to the appearance of language. At each of these transitions in the history of the cosmos and of the Earth, new organizations of matter appeared that were not present previously, at least at those locations. From this perspective, the transition that separates living processes from other physical-chemical processes is only one among many emergent transitions, such as the formation of the first stars or the production of heavy elements in dying stars.

But just being the first instance of something, or being novel or unpredictable, are not particularly helpful distinctions. Newness is in one sense the very nature of all physical change. However, a consideration of the sorts of transitions that characterize emergences for Morowitz indicates that there is a hierarchic aspect to this conception of emergence. Each transition involves the formation of a higher-order structure or process out of the interrelations.h.i.+ps of smaller, simpler components. Emergence in this sense involves the formation of novel, higher-order, composite phenomena with coherence and autonomy at this larger scale.

What about predictability? Being unpredictable, even in some ultimate sense, is only a claim about the limits of representation-or of human intellect. Even if certain phenomena are ”in principle” unpredictable, unexplainable, or unknowable, this doesn't necessarily imply a causal discontinuity in how the world works. There may be a determinate path from past to future, even to a radically divergent form of future organization, even if this causal influence is beyond precise representation. Indeed, all representations of worldly events are simplifications, so we should expect to find many physical transitions that exceed our capacity to represent the basis of this transition. And it is often the case that what was once beyond predication becomes more tractable with better representational tools and more precise measuring instruments. The history of science has provided many examples of what once were apparently mysterious phenomena, a.s.sumed to be intrinsically intractable, that eventually succ.u.mbed to unproblematic scientific explanation. Such was the case with the once mysterious forces constraining the possible trans.m.u.tations of substances, as explored by alchemists, which were eventually explained by chemistry, and to an even greater depth with quantum physics.

Without question, phenomena such as life and mind owe some of their mysterious character to limitations in our present state of science. I'm confident that these limitations of our current theoretical tools can be overcome and that these phenomena can also become integrated into the larger fabric of natural science. The question is whether in accomplis.h.i.+ng this, their distinctive ententional characteristics (function, representation, end-directedness, self, and so on) will be explained rather than merely explained away.

What is interesting and challenging about ententional phenomena is that they appear to involve a global reorganization of their component dynamical interactions and interdependencies that only makes sense with respect to non-intrinsic relations.h.i.+ps. So proving ultimate unpredictability isn't critical, nor do we need to demonstrate a kind of radical discontinuity of causal influence. But we do need to explain how such phenomena can exhibit causal organization that is (superficially at least) the inverse of the pattern of causal organization which is otherwise ubiquitously present throughout the inanimate world. Instead of postulating discontinuous jumps, in which novel physical properties appear like rabbits out of empty hats as we cross certain thresholds of compositionality, we might better focus on making sense of the apparent causal reversals that motivate these special accounts. As in a magic act, there can be subtle effects that are difficult to detect, and there can be cognitive biases that cause us to look in the wrong place at the wrong time, thus missing the important features. We just need to know what to look for, and what we can ignore.

THE EVOLUTION OF EMERGENCE.

The concept of emergence is fairly new in the history of science. This is because it was originally formulated as a contrast to a causal paradigm that only reached its full elaboration in the nineteenth century. By the mid-nineteenth century, a more thoroughly mechanistic and statistical approach to natural philosophy had begun to coalesce and displace the previously more teleological and platonic forms of explanation. At midcentury, electricity and magnetism were being tamed, the general concept of energy was becoming formalized, thermodynamic principles were being derived from micro-Newtonian dynamics, and alchemy was being replaced by an atomic theory of chemical interactions. Even the complex logic of organism design and adaptation appeared subject to entirely material processes, as outlined in Charles Darwin's theory of natural selection. Herbert Spencer had even suggested that these same principles might be applicable to human psychology and social processes. Mystical powers, intangible forces, immaterial essences, and divine intervention in the goings-on of nature were seen as prescientific anachronisms. Nature's designs, including living and mental processes, were now viewed through the lens of materialism: reducible to matter in motion. Antecedent teleology and metaphysical claims concerning the directionality of evolutionary change were no longer legitimate scientific a.s.sumptions.

This posed some troubling questions. Given their superficially inverted form of causal influence-with current processes structured with respect to future possibilities-how can the teleological appearance of living and mental processes be accounted for in these same terms? And if these ententional properties are not already prefigured in the inorganic world, how can their novel features be derived from those non-ententional processes alone? In response to these challenges, a number of scientists and philosophers of science realized the necessity of reconciling the logic of physical science with the logic of living and mental teleology. A true reconciliation would need to accept both the unity of material and living/mental processes and the radical differences in their causal organization. Investigators could neither accept ententional properties as foundational nor deny their reality, despite this apparent incompatibility. The key concept that came to characterize an intermediate position was that of emergence.

This use of the term was introduced by the English philosopher and critic George Henry Lewes, in his Problems of Life and Mind (187479), where he struggles with the problem of making scientific sense of living and mental processes. He defines emergence theory as follows: Every resultant is either a sum or a difference of the co-operant 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 h.o.m.ogeneous 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 insofar as these are incommensurable, and it cannot be reduced to their sum or their difference.2 Lewes appears to have been influenced by John Stuart Mill's effort to unite logic with the methodologies of such new sciences as chemistry and biology. Mill was particularly struck by discontinuities of properties that could be produced by combinatorial interactions such as chemical reactions. Thus two toxic and dangerous substances, chlorine gas and sodium metal, when combined together, produced common table salt-which is both ubiquitous and an essential nutrient in the living world. The chemical reaction that links these two elements neutralizes their highly reactive natures and in their place yields very different ionic properties on which all life depends. Mill viewed this radical change in properties due to chemical combination to be a.n.a.logous to the combinatorial logic that produced life from mere chemistry. He argues in A System of Logic that All organised bodies are composed of parts, similar to those composing inorganic nature, and which have even themselves existed in an inorganic state; but the phenomena of life, which result from the juxtaposition of those parts in a certain manner, bear no a.n.a.logy to any of the effects which would be produced by the action of the component substances considered as mere physical agents. To whatever degree we might imagine our knowledge of the properties of the several ingredients of a living body to be extended and perfected, it is certain that no mere summing up of the separate actions of those elements will ever amount to the action of the living body itself.3 Over the course of the previous centuries, the idea that living organisms might be machinelike and constructed of the same basic chemicals as inorganic objects had gained credence, but an account of how organism structure and function arose was still mysterious. Before Darwin, their exquisite construction was generally a.s.sumed to be the work of a ”divine intelligence.” But even centuries before Darwin, the successes of materialist science had convinced many that a spontaneous mechanistic approach had to be possible. This notion was given added support by the success of the empiricist theory of mind described by John Locke in the late 1600s. Locke's account of the gradual and spontaneous development of complex ideas out of the a.s.sociation of sense data acquired via interaction with the world provided an atomistic notion of knowledge as the compound resulting from the a.s.sociative bonds between these ”atoms” of experience. That the complex interrelations of ideas could be the result of the environmental impressions on a receptive medium suggested to Locke that a material a.n.a.logue might also be conceivable. In the century and a half that followed, thinkers like Erasmus Darwin (Charles' grandfather) and later Jean-Baptiste de Lamarck struggled to articulate how an a.n.a.logous process might also explain the way that the adaptively a.s.sociated combinations of parts which const.i.tuted plant and animal bodies might have similarly arisen. As Locke had conceived of mind forming from an unformed merely impressionable beginning, couldn't the a.s.sociation of living processes arise from the living equivalent of a blank slate? If such functional a.s.sociations could arise by spontaneous mechanism, then antecedent design would be redundant.

This turned the cla.s.sic ”Chain of Being” logic on its head. As Gregory Bateson has described it, Before Lamarck, the organic world, the living world, was believed to be hierarchic in structure, with Mind at the top. The chain, or ladder, went down through the angels, through men, through the apes, down to the infusoria or protozoa, and below that to the plants and stones. What Lamarck did was to turn that chain upside down. When he turned the ladder upside down, what had been the explanation, namely: the Mind at the top, now became that which had to be explained.4 Previously, starting with the a.s.sumption of the infinite intelligence of a designer G.o.d, organisms-including those capable of flexible intelligent behavior-could be seen as progressive subtractions and simplifications from G.o.dlike perfection. In the ”Great Chain of Being,” mental phenomena were primary. The mind of G.o.d was the engine of creation, the designer of living forms, and the ultimate source of value. Mind was not in need of explanation. It was a given. The living world was derived from it and originally folded within it, preformed, as a definite potential. The evolutionary reconception proposed by the elder and younger Darwins, Lamarck, and others therefore posed a much more counterintuitive possibility. Mind and its teleological mode of interacting with the world could be described as an end product-not an initiating cause-of the history of life. Lamarck's vision of evolution was in this sense ultimately emergent. He conceived of life in purely materialistic terms, and his evolutionary argument proposed a means by which mind might have emerged in a continuous process from otherwise mindless processes. Mill's a.n.a.lysis opened the door to thinking of this a.s.sociation process as potentially resulting in something quite unlike the ”atoms” (whether experiential or chemical) from which the process began.

The event that probably played the key role in precipitating the articulation of an emergentist approach to life and mind was the publication in 1859 of Darwin's On the Origin of Species. Although Darwin was not particularly interested in the more metaphysical sorts of questions surrounding the origins of mind, and did not think of his theory in emergence terms, he was intent on addressing the teleological issue. He, like Lamarck, was seeking a mechanistic solution to the problem of the apparent functional design of organisms. But where Lamarck a.s.sumed that the active role of organism striving to adapt to its world was necessary to acquire ”instruction” from the environment-a cryptic homunculus-Darwin's theory of natural selection required no such a.s.sumption. He reasoned that the same consequence could be reached due to the differential reproduction of blindly generated variant forms of organisms in compet.i.tion for limited environmental resources. This eliminated even the tacit teleological a.s.sumption of a goal-seeking organism. Even this attribute could be achieved mechanistically. Thus, it appeared that teleology could be dispensed with altogether.

The theory of natural selection is not exactly a mechanistic theory, however. It can best be described as a form of statistical inference that is largely agnostic about the mechanisms it depends on. As is well known, Darwin didn't understand the mechanism of heredity or the mechanisms of reproduction. He didn't have a way to explain how forms are produced during development. And he didn't have an account of the origins of spontaneous variations of organism form. But he didn't need them. As a keen observer of nature, he saw the regular consequences of these mechanisms (e.g., inheritance of traits, compet.i.tion for the resources needed to develop and reproduce, and individual variation) and drew the inevitable statistical implications. Fittedness of organisms to their environment was a logical consequence of these conditions.

What Galileo and Newton had done for physics, Lavoisier and Mendeleyev had done for chemistry (and alchemy), and Carnot and Clausius had done for heat, Darwin had now done for the functional design of organisms. Functional design could be subsumed under a lawlike spontaneous process, without need of spirits, miracles, or extrinsic guidance.

Of course, there were many (including Alfred Russel Wallace, the co-discoverer of natural selection) who felt that the argument could not be extended to the domain of mental agency, at least as is implicit in human experience. Even though Wallace agreed that the teleological influence of a divine intelligence was unnecessary to explain organism design in general, there were features of human intelligence that seemed to be discordantly different from what would have been merely advantageous for survival and reproduction. Despite these misgivings, as the nineteenth century waned and the twentieth century began, it became easier to accept the possibility that the mechanistic view of life could also be imagined to hold for mind. Teleology appeared to be tameable, so long as it was evolvable. If functional design could arise as an after effect of accidental variation, reproduction, and resource compet.i.tion, then why not mental function as well?

Yet it wasn't quite this simple. Mental processes are defined in teleological terms. Although the evolutionary paradigm offered a powerful unifying framework that promised to answer vast numbers of puzzling questions about biological function and design, it also drew attention to what was previously an irrelevant question.

If a teleological account of organism design is actually superfluous, then couldn't it also be superfluous to an account of the teleological features of thought as well? To put it more enigmatically, couldn't Darwinian logic allow science to dispense with teleological accounts at all levels and in all processes? This is of course the motivation behind the various ”golem” arguments we critiqued in chapter 3. If something as complex as the fitted functional organization of a body and brain can be generated without the a.s.sistance of teleology, then why should we a.s.sume that complex adaptive behavior, including even human cognition, requires a teleological account to make sense of it? The rise of emergentism in the late nineteenth and early twentieth century can be seen as an effort to rescue teleological phenomena from this ultimate elimination by conceiving of them as derived from a sort of cosmic evolution. With the Great Chain of Being inverted, teleology must be constructed.

REDUCTIONISM.

Emergentism was also a response to another achievement of nineteenth-century science: a new methodology for a.n.a.lyzing nature known as reductionism. If complicated phenomena can be a.n.a.lyzed to component parts, and the properties of the parts a.n.a.lyzed separately, then it is often possible to understand the properties of the whole in terms of the properties and the interactions of these parts. This approach was highly successful. The atom theory of chemistry had made it possible to understand the properties of different substances and their interconvertability in terms of combinatorial interactions between more basic elemental units, atoms, and molecules. The understanding of heat and its convertability into motive power was explained in terms of the movements of molecules. Even organisms could be understood in terms of cellular interactions. Reductionistic a.n.a.lysis was a natural extension of the atomism that began with ancient scholars like Empedocles and Democritus. Atomism was just the extreme form of a tried-and-true explanatory strategy: break complex problems into simpler parts, then if necessary break these into even smaller parts, and so on, until you can go no further or else encounter ultimately simple and indivisible parts. Such indivisible parts-called atoms (literally, ”not cut-able”)-should, by a.s.sumption, exhibit less complicated properties and thereby reduce complicated collective properties to combinations of simpler properties. Of course, the quest to find nature's smallest units has led to the discovery that the atoms of matter are not indivisible, and even to the realization that the particles that const.i.tute them may be further divisible as well.

All macroscopic objects are indeed composed of smaller components, and these of yet smaller components. So the a.s.sumption that the properties of any material object can be understood in terms of the properties of its component parts is quite reasonable. Thomas Hobbes, for example, argued that all phenomena, including human activity, could ultimately be reduced to bodies in motion and their interactions. This was an a.s.sumption that birthed most of modern science and set it on a quest to dissect the world, and to favor explanations framed at the lowest possible level of scale.

Reflecting on this a.s.sumption that smaller is more fundamental, the Canadian philosopher Robert Wilson dubbed it ”smallism.”5 It is not obvious, however, that things do get simpler with descent in scale, or that there is some ultimate smallest unit of matter, rather than merely a level of scale below which it is not possible to discern differences. Nevertheless, it is often the case that it is possible to cleanly distinguish the contributions of component objects from their interactions in explaining the properties of composite ent.i.ties. Unfortunately, there are many cases where this neat segregation of objects and relations.h.i.+ps is not possible. This does not mean that complex things lack discernable parts, only that what exactly const.i.tutes a part is not always clear. Nevertheless, phenomena susceptible of simple decomposition led to many of the greatest success stories of Western science.

By the middle of the nineteenth century, it was becoming obvious that the chemistry of life was continuous with the chemistry that applied to all matter. Living metabolism is in this sense just a special case of linked chemical reactions. The discovery of the structure of DNA at the middle of the twentieth century marked the culmination of a century-long effort to identify something like the philosopher's stone of living processes, and was widely heralded as the ”secret of life.” In a parallel science, it was becoming clear that the smallest units of chemical reactions-atoms-were themselves composed of even smaller components-electrons, protons, and neutrons-and these were eventually found to be further dissectible. The study of brain function likewise progressed from b.u.mps on skulls to the ultrastructure of neurons and synapses. Contemporary neuroscience can boast a remarkably detailed and nearly complete theory of synaptic function, and only a slightly less complete understanding of neurons. In all these sciences, the push to understand the properties of ever smaller and presumably more basic components has led to a profoundly thorough map of the microverse of elementary physical particles, and yet has made comparatively less dramatic progress toward a theory of ordinary-scale compositional dynamics and systemic functions, especially when it comes to ententional phenomena.

A critical shortcoming of methodological smallism, despite its obvious successes, is that it implicitly focuses attention away from the contributions of interaction complexity. This gives the false impression that investigating the organizational features of things is less informative than investigating component properties. This bias has only quite recently been counterbalanced by intense efforts to study the properties of systems in their own right. The sciences of the twenty-first century have at last begun to turn their attention away from micro properties and toward problems of complex interaction dynamics. As the astrophysicist Stephen Hawking has said: ”I think the next century will be the century of complexity.”6

THE EMERGENTISTS.