San Diego Law Review
Document Type
Article
Abstract
Traditional accounts of the common law from Blackstone to Dworkin focus on the role of precedent in judicial decision-making, the metaphysical nature of law, and the heroic judge. As important as these perspectives are, they miss the essence of the common law, which is that it is a “complex adaptive system,” with the capacity to process vast amounts of information and broadly impact individuals and society in unexpected ways.
Complexity Theory—the study of decentralized, yet self-organizing systems and the emergent phenomena they produce—has been applied to study real-world systems as wide-ranging as the immune system, insect colonies, the global economy, and evolving ecosystems. It helps explain how such systems engage in behaviors and outcomes that appear greater than the sum of their parts. But it has yet to enter the mainstream of legal study.
The lack of attention in law to Complexity Theory is not surprising, as it is a relatively new development. But it puts the common law into an entirely new light, explains some of its hitherto difficult-to-explain (or in some cases ignored) aspects, and points to important directions of future research. Furthermore, Complexity Theory explains how common law generates doctrinal outcomes that are fundamentally unpredictable, despite the legal profession’s self-conscious focus on rationality and the logical progression of caselaw.
In considering common law through the lens of Complexity, this Article demonstrates that the party-control principle—one of common law’s defining features—has particular significance. This principle is insufficiently considered in traditional accounts of common law (which most often focus on the nature of common-law reasoning), and also has yet to be fully treated in the growing field of Complexity-and-Law studies. But analyzing common law’s adversarial mechanisms through Complexity illuminates why the common law is far more complicated, unpredictable, and interesting than traditional theories might suggest. It also suggests why common law, as unpredictable as it may appear, may actually promote liberty, economic progress, and human flourishing in the real world. It does so, however, not by “working itself” pure or evolving into a stable state, as previous exegeses of the common law suggest, but instead by tolerating and exploiting inconsistencies and contradictions. This turns the normal analysis of the common law on its head.
Recommended Citation
Ronald J. Allen & Paul Piazza,
The Common Law is a Complex Adaptive System,
63
San Diego L. Rev.
193
(2026).
Available at:
https://digital.sandiego.edu/sdlr/vol63/iss2/2