Coherence Universalism — Biology: Life as Coherence Under Constraint Volume 3 of the Coherence Universalism Series — G. K. D. Rader — Heaven≡Earth Foundation, 2026 What is life? Not biochemically — structurally. What distinguishes a living system from a merely complex one? And what does the answer reveal about the origin of life, the logic of development, and the deep structure of evolution? This volume extends the Coherence Universalism framework from physics to biology, arguing that life is defined by a single structural transition: the shift from passive to actively self-maintaining coherence. A living system is one that detects threats to its own coherence and acts to preserve it — investing energy, repairing damage, and navigating toward viable configurations in its state space. Abiogenesis as Phase Transition. The origin of life is reframed as a coherence phase transition rather than a chemical accident. Life begins when there exists a bounded region in state space such that a system starting within it returns to it with high probability. The paper specifies the formal conditions for this transition and derives the coherence maintenance inequality: living systems must continuously invest energy to maintain their coherence against entropic degradation. The Viability Set. Living systems operate within a viability set — the region of state space within which the system can function. The viability set is not fixed but dynamically maintained. When it contracts, the system faces crisis. When it expands, new capacities become available. Development, adaptation, and evolution are all navigations within and expansions of viability space. Morphogenesis and Development. The emergence of biological form is treated as coherence propagation under constraint — the progressive differentiation of structure through processes that maintain global coherence while generating local specialization. The paper develops formal conditions for how a single cell's coherence dynamics can produce the coordinated complexity of a multicellular organism. Evolution Reconsidered. Natural selection is reframed as a coherence filter operating on populations. What persists is not the fittest in any absolute sense but whatever maintains viable coherence under the constraints actually encountered. The framework predicts specific features of evolutionary dynamics — including the prevalence of convergent evolution, the structure of evolutionary radiations, and the relationship between evolvability and constraint. Embedded Intelligence. The paper develops CU's account of biological intelligence as coherence navigation under constraint — the capacity of organisms to solve genuinely novel problems by following coherence gradients rather than relying on stored solutions. This capacity is graded, present in rudimentary form in simple organisms and reaching remarkable sophistication in complex ones, and it provides the biological foundation for the psychological and social coherence developed in later volumes. The biology volume bridges the gap between the mathematical foundations established in the Physics paper and the phenomenological richness that emerges in the Consciousness and Psychology papers. Heaven≡Earth Foundation · heavenearthfoundation.org · 2026