Life as Bounded Relational Dynamics: A Constitutive and Operational Synthesis for Mammalian Physiology

What does the life of a mammalian cell, organ or organism consist in? A material inventory is insufficient: components turn over during continued life, organism-level integration may fail while many components remain intact, and local cells can remain viable after the larger individual dies. We defend a constitutive, scale-declared interpretation: the actual living process of a mammalian system is its materially realized, selectively bounded and self-maintaining relational dynamics, not a separate entity produced by those dynamics. The argument is one of comparative explanatory adequacy, not a novel necessary-and-sufficient classifier. The strongest competing account treats life as a physical disposition or capacity to sustain and resume characteristic functions, a problem already examined in general disposition metaphysics and in cryptobiosis literature. We distinguish current enactment of organized activity from physical organization preserving the capacity to reactivate it: vitrified embryos provide a limiting case. During deep storage, ordinary embryo-scale developmental activity is strongly suppressed while the physical prerequisites for reactivation can remain, just as a dry river channel can permit renewed flow when suitable conditions return. This distinction permits suspended viability without positing the uninterrupted operation of physiological metabolism. A compact state–relation formalism separates measured physical states from effective causal couplings and makes explicit their joint, history-dependent change, while remaining a coarse model, not a whole-animal simulator. Mammalian intestinal barriers and exercise-induced skeletal-muscle adaptation anchor the analysis. Existing process ontology, autopoiesis, constraint closure, relational biology and physiological control theories anticipate much of the proposal; an original empirical advantage is not claimed. The paper’s contribution is a bounded explanatory reconstruction and an explicit discipline for applying it.