Watch a murmuration. Somewhere over Rome or over the Somerset Levels at dusk, a hundred thousand starlings coalesce into a single fluid mass — expanding, contracting, bending, folding around itself like a living liquid, rolling in waves that cross the sky faster than any individual bird could coordinate. No bird leads. No bird has a map or a plan. The flock has no brain, no director, no blueprint. And yet it moves with extraordinary coherence, responding to threats, dividing and reuniting, maintaining its integrity against the wind. For decades, ornithologists assumed there must be leaders somewhere, a communication system, a hierarchical structure. When Andrea Cavagna and colleagues at the Institute for Complex Systems in Rome finally analyzed the mathematics of starling murmurations in a series of papers beginning in 2010, using high-speed stereoscopic cameras and computational analysis, they found something different: each bird follows three simple local rules. Match the velocity of your seven nearest neighbors. Stay close but avoid collision. Move away from predators. That is all. Three rules, no leader, no global awareness — and from those ingredients, thousands of birds generate one of the most complex, beautiful, and coordinated behaviors in nature.

Where is the flock? This is not a trivial question. You can identify any individual starling in the murmuration. You can describe all their positions and velocities at any moment. But the flock — the fluid collective entity, the wave patterns, the anti-predator shape-shifting — is nowhere in any individual bird. It exists only in the relations between birds, at a level of organization that the description of any single bird cannot reach. This is emergence: the appearance of properties, patterns, and behaviors at higher levels of organization that cannot be found in, or predicted from, the individual components alone.

Emergence is one of the most fundamental and most misunderstood concepts in science and philosophy. It appears in physics, chemistry, biology, ecology, economics, neuroscience, and social science. It is the answer to questions as varied as why temperature exists, why water is wet, why cities develop characteristic spatial patterns without planners designing them, and possibly why conscious experience arises at all. Understanding emergence means understanding how complexity is possible — how genuinely new things can arise in a universe governed by laws that operate at the level of particles.

"The ability to reduce everything to simple fundamental laws does not imply the ability to start from those laws and reconstruct the universe. At each level of complexity, entirely new properties appear." — Philip W. Anderson, Science (1972)


Key Definitions

Emergence: The appearance of properties or behaviors at higher levels of organization that are not present in, and cannot be straightforwardly predicted from, the individual components of a system.

Weak emergence: Emergence that is in principle computable from lower-level rules but is practically unpredictable without simulating the system. The vast majority of emergence in nature is of this type.

Strong emergence: Emergence that is claimed to be genuinely irreducible — not merely practically unpredictable but logically independent of any lower-level description. Consciousness is the most commonly proposed candidate.

Complex adaptive system: A system of many interacting agents that adapt or learn based on local information, producing collective emergent behavior that cannot be predicted from individual behavior.

Self-organized criticality: The tendency of many complex systems to self-organize to a critical state between order and chaos, where they exhibit power-law distributed fluctuations at all scales.

Reductionism: The scientific strategy of explaining higher-level phenomena by analyzing their lower-level components. Reductionism is a powerful tool but, as Anderson argued, does not automatically provide complete understanding of emergent phenomena.

Phase transition: A change of state in a physical system (such as water freezing to ice) that is a collective phenomenon — a genuinely emergent behavior of the system as a whole, not a property of individual molecules.


The Problem of Reduction

Philip Anderson won the Nobel Prize in Physics in 1977 for his work in condensed matter physics — the study of how matter organizes itself at the scale of materials rather than particles. In a short but enormously influential 1972 article in Science, "More Is Different," he articulated something that had been implicit in his work but rarely stated so clearly: the reductionist program of science, while valid as far as it goes, does not capture all of science. The fact that everything is, at some level, physics does not mean that physics explains everything.

Anderson's argument proceeded by example. Particle physics describes the fundamental constituents of matter and the forces between them. Nuclear physics builds on particle physics. Atomic and molecular physics builds on nuclear physics. Solid-state physics builds on atomic physics. Chemistry builds on atomic and molecular physics. Molecular biology builds on chemistry. Cell biology builds on molecular biology. And so on up through physiology, psychology, social science. At each step, new phenomena appear — phenomena that require genuinely new concepts, new laws, and new experimental methods. The concept of temperature has no meaning at the particle level; the concept of a gene has no meaning at the particle level; the concept of a social norm has no meaning at the particle level. These are not failures of reduction — they are legitimate, irreducible features of organization at different scales.

This has a direct implication for how science works. The ability to reduce a phenomenon to lower-level physics does not give you the ability to predict or understand it from the lower level alone. You need theories and concepts appropriate to the level of organization you are studying. The emergence of higher-level phenomena is not a gap in understanding waiting to be filled by better physics — it is a fundamental feature of how complex systems work.

Emergence in Physics: Temperature, Phase Transitions, and Self-Organization

The clearest examples of emergence in physics come from thermodynamics and statistical mechanics. Temperature is perhaps the most familiar: it is not a property of any individual molecule in a gas, but of the statistical distribution of molecular kinetic energies in the collective. When we say a gas is at 300 Kelvin, we are describing something that belongs to the ensemble of molecules, not to any individual molecule. This is genuine emergence — temperature requires a new concept that has no analog at the molecular level.

Phase transitions are even more revealing. Water at 1 degree Celsius is liquid; at -1 degree Celsius it is solid ice. The difference in molecular arrangement is small. But the collective properties are radically different: rigidity, crystalline structure, heat capacity, and optical properties change discontinuously at the phase transition point. These collective properties are emergent: they belong to the organized system, not to individual molecules.

Per Bak, a Danish physicist, proposed in the late 1980s that many complex systems naturally evolve to a critical state — the boundary between order and chaos — where fluctuations occur at all scales simultaneously. Bak called this self-organized criticality, and he illustrated it with the sand pile model: add grains of sand to a pile, and it will self-organize to a critical angle at which avalanches of all sizes occur, following a power-law distribution. The same power-law distribution characterizes earthquakes (Gutenberg-Richter law), forest fires, solar flares, stock market crashes, and extinction events. These are not coincidences — they reflect the same underlying dynamics of self-organized criticality in complex systems near a critical point. The large events are not statistical outliers but intrinsic properties of systems organized near criticality.

From Chemistry to Life: Emergence at the Molecular Level

Water is a pedagogically useful molecule for emergence. Its constituent atoms — two hydrogen, one oxygen — are among the simplest in chemistry. Hydrogen and oxygen separately are colorless, flammable gases. But the water molecule's distinctive geometry (the oxygen's two lone electron pairs force the hydrogen atoms into a 104.5-degree angle) produces asymmetric charge distribution that makes water polar, enabling hydrogen bonding between molecules. From this molecular architecture emerge the properties that make water essential for life: unusual density (ice floats, which is critical for aquatic life in cold climates), high heat capacity (water buffers temperature), high surface tension (which enables capillary action in plant vascular systems), and the capacity to dissolve a wide range of solutes. None of these properties exist in hydrogen or oxygen atoms; all of them emerge from the organization of atoms in the water molecule and the collective behavior of water molecules interacting.

Life itself is the most dramatic example of chemical emergence. No individual carbon atom is alive. No amino acid is alive. But specific arrangements of amino acids in proteins, organized into cells with membranes, metabolic pathways, and nucleic acid-based information storage and replication, produce entities that grow, reproduce, respond to their environment, and evolve. The transition from chemistry to biology is not a matter of some additional "vital force" — it is emergence: new collective properties arising from the organization of non-living chemistry.

Stuart Kauffman, a theoretical biologist at the Santa Fe Institute, has investigated the origins of this emergence in a series of books including "The Origins of Order" (1993) and "At Home in the Universe" (1995). Kauffman argues that sufficiently complex chemical networks inevitably become self-catalyzing: as the number of molecular species and the diversity of reactions between them increases, the probability that some subset of molecules catalyzes the formation of other molecules in the set crosses a threshold, producing autocatalytic closure — the chemical equivalent of life's self-sustaining metabolism. Life, on Kauffman's view, is not a miraculous accident but an emergent property of sufficiently complex chemistry.

Conway's Game of Life: Emergence from Pure Logic

John Conway's Game of Life, devised in 1970, is the most famous demonstration of emergence in computational systems. The "game" is a cellular automaton: a two-dimensional grid of cells, each either alive or dead, that evolves according to four rules. A live cell with fewer than two live neighbors dies (underpopulation). A live cell with two or three live neighbors survives. A live cell with more than three live neighbors dies (overpopulation). A dead cell with exactly three live neighbors becomes alive (reproduction). Four rules. No other information. And from these four rules emerge patterns of extraordinary complexity: stable structures (still lifes), oscillators that cycle through periodic states, gliders that move across the grid, guns that fire gliders, and patterns capable of universal computation — the Game of Life can simulate any Turing machine. Structures that look nothing like any of the four rules appear spontaneously from initial conditions that give no hint of them.

The Game of Life is an example of what Chalmers calls weak emergence: every pattern in it is, in principle, computable from the initial conditions and the four rules, given sufficient processing time. Nothing in the Game of Life violates or transcends its rules. But this predictability in principle does not diminish the genuine novelty of what emerges — structures and behaviors that require new concepts to describe, that could not have been anticipated by inspecting the rules alone.

Ant Colonies: Emergence Without Intelligence

Deborah Gordon has spent over thirty years studying harvester ant colonies in the Arizona desert. Her research, summarized in "Ant Encounters: Interaction Networks and Colony Behavior" (2010), documents in meticulous detail how ant colonies make collective decisions, regulate foraging activity, allocate labor, and maintain colony function — all without any ant having access to information about the colony's overall state.

Ants communicate through pheromones — chemical signals that encode limited information about local conditions. A forager returning with food deposits trail pheromone; the strength of the signal indicates the quality of the food source; other foragers follow stronger signals. The colony's aggregate foraging strategy — where it forages, how many ants to deploy, when to expand or contract foraging activity — emerges from the sum of these local interactions. The colony's "decision" to reduce foraging when water is scarce (saving energy) emerges from individual ants responding to chemical signals about local conditions, with no ant comprehending the colony's energy budget.

What makes this remarkable is not just that the colony achieves apparently intelligent outcomes without any individual intelligence, but that the relevant level of description — the colony level — requires concepts (energy budget, foraging strategy, labor allocation) that have no meaning at the individual ant level. The colony is genuinely more than the sum of its ants.

Emergence in Social Systems

The social world is built from emergent phenomena. Language is emergent: no individual invented it, no authority designed it, no committee approved the grammar rules of English. Language evolved from the interactions of people using vocal communication, with successful patterns spreading and unsuccessful ones dying out, gradually crystallizing into stable grammatical structures that are neither arbitrary nor designed. The rules of English grammar are emergent properties of millions of linguistic interactions over centuries.

Markets are emergent. The price of wheat on the Chicago Mercantile Exchange is not set by any individual, not planned by any authority, not the result of any deliberate design. It emerges from the aggregate buying and selling decisions of thousands of traders, farmers, and processors responding to information about supply, demand, weather, transportation, and policy. Friedrich Hayek's insight — that the price system aggregates dispersed information that no central authority could collect and process — is an insight about emergence: prices are a collective phenomenon that encodes more information than any of their participants possess individually.

Cities exhibit emergence in spatial form. No city planner designed the street layouts, business districts, residential zones, and transportation networks of organically growing cities. These patterns — the clustering of similar businesses, the emergence of bohemian quarters that then gentrify, the development of commuter corridors — emerge from the aggregate decisions of individuals and firms responding to each other's locations. Economist Alain Bertaud, in "Order Without Design" (2018), documents how urban spatial patterns that appear designed are in fact emergent outcomes of individual locational choices constrained by infrastructure.

Emergence and Consciousness: The Hard Problem

Consciousness is the most contested domain of emergence. The working assumption of cognitive neuroscience is that conscious experience arises from — and is ultimately identical with — patterns of neural activity in the brain. The research program of mapping neural correlates of consciousness (NCCs) attempts to identify which brain states correspond to which conscious experiences, with the hope that a sufficiently complete mapping will constitute an explanation.

But David Chalmers, in "The Conscious Mind" (1996) and subsequent work, argues that this research program, however successful, leaves a fundamental question unanswered: why is there any subjective experience at all? Even a complete functional description of the brain — explaining how it processes visual information, integrates sensory signals, generates behavioral responses — would not, Chalmers argues, explain why there is something it is like to be a brain in those states. The redness of red, the painfulness of pain — these qualitative aspects of experience seem, to Chalmers, to require a different kind of explanation than functional analysis can provide.

Giulio Tononi's Integrated Information Theory (IIT) attempts to address this within a physicalist framework. IIT holds that consciousness is identical to integrated information — measured by a quantity called phi — which quantifies how much more information a system generates as a whole than the sum of its parts. Consciousness, on this view, is a genuinely emergent property of highly integrated systems, present in any physical system with sufficiently high phi, including potentially non-biological systems. IIT makes testable predictions about which physical systems are conscious and which are not, though testing them remains technically challenging.

Whether consciousness is weakly or strongly emergent remains genuinely open. What is not open is that it arises from physical brain processes and could not exist without them. The emergence of subjective experience from neural matter is, at minimum, the most striking example of weak emergence in nature — and possibly the only known instance of strong emergence.

Why Emergence Matters

Emergence is not merely a philosophical curiosity. It has direct implications for how science is organized, how research is funded, how models are built, and how interventions in complex systems should be designed.

If emergent phenomena require their own conceptual frameworks and cannot be understood purely by reducing to lower levels, then every level of organization in nature deserves its own science — and the pecking order that treats physics as the most fundamental and social science as the most derivative is a distortion. Ecology is not inferior physics; economics is not inferior neuroscience. They study genuinely different levels of organization, with genuinely different emergent phenomena requiring genuinely different methods.

Agent-based modeling — the computational approach of simulating populations of interacting agents following local rules and observing what collective behavior emerges — has become a significant tool in epidemiology (modeling disease spread), economics (modeling market dynamics), ecology (modeling population dynamics), and urban planning (modeling traffic and land use). It is explicitly an approach designed to study emergence: rather than specifying aggregate outcomes, it specifies individual rules and allows aggregate behavior to emerge.

The recognition that many of the most important phenomena in the world — from public health to financial stability to climate tipping points — are emergent properties of complex adaptive systems has profound implications for intervention and policy. You cannot control an emergent system by controlling its individual components; you must work with the logic of emergence, designing incentives and rules that shape local interactions in ways that produce desired collective outcomes. The history of failed top-down interventions in complex social systems — from Soviet central planning to the US drug war to urban renewal projects that destroyed communities — is in part a history of ignoring emergence.

Understanding emergence means accepting that the universe is not a giant mechanism whose behavior can be predicted by solving the equations of physics at the finest scale. It is a nested hierarchy of organization, each level with its own laws, its own structures, and its own emergent properties — each level real, each level irreducible to the one below, each level requiring its own framework for understanding. The murmuration is not the sum of the birds. The mind is not the sum of the neurons. And knowing the parts, however precisely, does not automatically give you the whole.

For related frameworks on how complexity evolves over time, see How Complex Systems Adapt. For emergence in biological evolution specifically, see How Evolution Works. For the deepest emergent puzzle, see How Consciousness Works.


References

  • Anderson, Philip W. "More Is Different." Science 177(4047): 393-396, 1972. https://doi.org/10.1126/science.177.4047.393
  • Chalmers, David J. The Conscious Mind: In Search of a Fundamental Theory. Oxford University Press, 1996.
  • Holland, John H. Emergence: From Chaos to Order. Addison-Wesley, 1998.
  • Kauffman, Stuart A. The Origins of Order: Self-Organization and Selection in Evolution. Oxford University Press, 1993.
  • Bak, Per, Chao Tang, and Kurt Wiesenfeld. "Self-Organized Criticality: An Explanation of the 1/f Noise." Physical Review Letters 59(4): 381-384, 1987. https://doi.org/10.1103/PhysRevLett.59.381
  • Cavagna, Andrea, et al. "Scale-Free Correlations in Starling Flocks." Proceedings of the National Academy of Sciences 107(26): 11865-11870, 2010. https://doi.org/10.1073/pnas.1005766107
  • Gordon, Deborah M. Ant Encounters: Interaction Networks and Colony Behavior. Princeton University Press, 2010.
  • Tononi, Giulio. "Consciousness as Integrated Information: A Provisional Manifesto." Biological Bulletin 215(3): 216-242, 2008. https://doi.org/10.2307/25470707
  • Haas, Ernst B. The Uniting of Europe. Stanford University Press, 1958. (Note: related to integration, cited for distinction)
  • Bertaud, Alain. Order Without Design: How Markets Shape Cities. MIT Press, 2018.

Frequently Asked Questions

What is emergence?

Emergence refers to properties, patterns, or behaviors that arise at higher levels of organization and cannot be straightforwardly predicted from — or reduced to — the properties and behaviors of lower-level components. When we say a property is emergent, we mean that it belongs to the collective rather than to any individual part: no single water molecule is wet, but water is; no individual neuron is conscious, but the brain (apparently) is; no individual driver intends to create a traffic jam, but traffic jams reliably emerge from individual driving decisions. The key idea is that the whole is not just the sum of its parts — the whole has properties that the parts, considered individually, do not possess. Emergence is distinguished from mere complication. A complicated system has many parts interacting in ways that are in principle fully predictable if you know all the component properties and all the interaction rules. Emergence involves something more: the appearance of genuinely novel properties at higher levels that require new concepts and laws to describe, not merely the application of lower-level descriptions at larger scale. Temperature, for example, is an emergent property of molecular motion — it is not the speed of any individual molecule but a statistical property of the collective. Wetness, surface tension, and fluid dynamics emerge from molecular interactions that, at the individual-molecule level, involve none of these phenomena. The concept appears across physics, chemistry, biology, ecology, economics, and cognitive science, making it one of the most general frameworks in contemporary science for thinking about how complex phenomena arise from simpler substrates.

What is the difference between weak and strong emergence?

The distinction between weak and strong emergence, formalized by philosopher David Chalmers among others, concerns whether emergent properties are in principle reducible to lower-level descriptions or whether they are genuinely irreducible in a deeper sense. Weak emergence describes properties that, while surprising and practically difficult to predict, are in principle computable from lower-level rules given sufficient information and processing power. Conway's Game of Life is a paradigm case: the complex gliders, oscillators, and patterns that emerge from four simple rules about cell states are genuinely unpredictable in practice without running the simulation, but they are not in principle irreducible — everything that happens in the Game of Life is fully determined by its initial conditions and rules. Temperature emerging from molecular motion is another example: it is surprising that heat, cold, and thermodynamic behavior emerge from quantum mechanical particle interactions, but there is no reason in principle why those phenomena cannot be fully derived from lower-level physics. Strong emergence, by contrast, refers to properties that are claimed to be genuinely irreducible — not merely difficult to predict but logically independent of any lower-level description. Consciousness is the most commonly invoked candidate: the subjective, qualitative experience of seeing red or feeling pain seems, to many philosophers, not derivable from any description of neural firing patterns, no matter how complete. If strong emergence is real, it would mean that the universe genuinely contains phenomena that cannot be understood through reductive analysis — a significant philosophical claim that many scientists find uncomfortable. Most contemporary scientists and philosophers accept weak emergence as commonplace and strong emergence as either nonexistent or confined to consciousness.

How does emergence appear in nature?

Emergence appears at virtually every level of natural organization. In physics, temperature, pressure, and phase transitions are emergent: the thermodynamic behavior of gases arises from the statistical mechanics of molecular motion, and the transition from liquid to solid at a specific temperature is a collective phenomenon with no counterpart at the molecular level. Phase transitions are particularly instructive — at the critical point, a system exhibits scale-invariant behavior, with fluctuations occurring at all scales simultaneously, which is a genuinely collective phenomenon that requires statistical mechanics to describe. In chemistry, the properties of water — its unusual density, surface tension, high heat capacity, and ability to form hydrogen bonds that make liquid water possible at Earth temperatures — emerge from the geometry of the H2O molecule and the quantum mechanical nature of oxygen-hydrogen bonding; none of these properties exist in isolated hydrogen or oxygen atoms. In biology, life itself is emergent: no individual carbon, hydrogen, oxygen, or nitrogen atom is alive, but specific arrangements of these atoms in specific molecular structures produce metabolism, self-replication, and responsiveness to environment. At higher biological levels, ant colony behavior — the ability of ant colonies to regulate temperature, allocate labor, find optimal foraging paths, and respond adaptively to threats — emerges from the behavior of individual ants following simple pheromone-based rules with no central coordination. Deborah Gordon's decades of research on harvester ants at Stanford has documented how sophisticated collective behavior emerges from local interactions without any ant having an overview of colony needs. At the ecosystem level, food webs, predator-prey cycles, and population dynamics are emergent properties of species interactions.

What are complex adaptive systems?

Complex adaptive systems are systems composed of many interacting agents that learn or adapt based on their interactions, producing emergent behavior at the collective level. The concept was developed primarily at the Santa Fe Institute, founded in 1984, through work by physicist Murray Gell-Mann, economist Kenneth Arrow, biologist Stuart Kauffman, and computer scientist John Holland, among others. Complex adaptive systems are distinguished by several features: they consist of many heterogeneous agents whose behavior depends on local information and past experience; their aggregate behavior cannot be predicted from individual behavior alone; they exhibit feedback loops, both positive (amplifying) and negative (stabilizing); they self-organize into patterns without central direction; and they adapt over time, with successful strategies spreading and unsuccessful ones diminishing. Examples include immune systems, financial markets, ant colonies, the brain, ecosystems, cities, and the global economy. Per Bak's concept of self-organized criticality, developed through the sand pile model in the late 1980s, added a further insight: many complex systems naturally evolve toward a critical state — a boundary between order and chaos — where they exhibit power-law distributed fluctuations and extreme sensitivity to perturbation. Earthquakes, forest fires, stock market crashes, and species extinction events all follow power-law distributions, suggesting they arise from systems operating near criticality. John Holland's 'Emergence: From Chaos to Order' (1998) provided one of the most accessible frameworks, arguing that emergence in complex adaptive systems could be understood through the interaction of building blocks following local rules, with higher-level patterns arising from the combinatorial possibilities of those interactions. The practical applications are significant: agent-based modeling, which simulates complex adaptive systems computationally, has been applied to epidemiology, traffic flow, financial market regulation, and organizational design.

Is consciousness an emergent property?

Whether consciousness is an emergent property is one of the most contested questions in philosophy of mind and cognitive science, and the answer depends significantly on whether one thinks strong emergence is possible. The position that consciousness is weakly emergent — that it arises from neural processes and is, in principle, fully explicable in terms of brain function — is the working assumption of most neuroscientists. On this view, consciousness is analogous to temperature or fluid dynamics: genuinely novel as a description, but not logically independent of the lower-level processes that produce it. The research program of neuroscience is largely motivated by this assumption, seeking to identify the neural correlates of consciousness (NCCs) — the specific brain states that correspond to specific conscious experiences. Giulio Tononi's Integrated Information Theory (IIT) attempts to formalize this: consciousness, in Tononi's framework, is identical to integrated information (measured as phi), a quantity that can in principle be computed from the causal structure of any physical system. David Chalmers's 'hard problem of consciousness' challenges the weak emergence view. Chalmers argues that even a complete functional description of the brain — explaining how it processes information, responds to stimuli, and generates behavior — would leave unexplained why there is any subjective experience at all, why there is something it is like to be a brain in a given state. This explanatory gap, he argues, may indicate that consciousness is strongly emergent — irreducible to physical description. The debate remains unresolved. What is agreed is that consciousness, whatever its ultimate nature, arises from physical brain processes and covaries with them in systematic ways. Whether that covariation is a reduction or a correlation between distinct levels of reality is the question that keeps philosophers and neuroscientists arguing productively.

Why does emergence matter for science and philosophy?

Emergence matters because it challenges a naive picture of how science works — the reductionist picture in which understanding the smallest parts of a system automatically provides understanding of the whole. Philip Anderson's 1972 Science article 'More Is Different' is the classic statement of this challenge. Anderson, a condensed matter physicist and Nobel laureate, argued that the ability to reduce everything in principle to fundamental physics does not mean that physics is the only science or that higher-level phenomena are merely applied physics. At each level of organization, he wrote, genuinely new laws, concepts, and phenomena emerge that require new scientific frameworks. The physicist studying elementary particles has no tools for understanding phase transitions; the molecular biologist studying protein folding has no tools for understanding natural selection; the neuroscientist mapping neural circuits has no tools for understanding social institutions. Each level requires its own science. This has practical consequences for research strategy: the reduction of higher-level phenomena to lower-level descriptions is not always possible or useful, and studying emergence at the appropriate level of description is often more productive than attempting reductive explanation. In philosophy, emergence bears on debates about physicalism (is everything ultimately physical?), multiple realizability (can the same mental state be realized in different physical substrates?), and scientific explanation (what counts as a genuine explanation?). In social science, the recognition that social phenomena are emergent — that institutions, norms, markets, and cultures are not simply the intentions of individuals writ large — has transformed methodology, producing agent-based modeling, complex systems approaches to economics, and network analysis of social structures. Understanding emergence is, in a sense, understanding how novelty is possible in a deterministic universe — how genuinely new things can arise from old materials following old rules.