An Alternative Understanding of Laws of Nature as Constraints: Constrained and Repeatable Behavior

Formulating laws of nature as constraints does not itself determine the physical basis of their restrictions. On the proposed account, a law is the regular and repeatable behavior of physical systems; its formulation expresses that behavior. Regularity is grounded in systems’ real properties and capacities. Possible states and responses also depend on basic relations of interaction and evolution and on how those capacities are realized in the joint state. In this sense, a law is an “endogenous constraint”: possibilities are restricted by this physical reality itself. Two equilibrium configurations with identical constituents and interaction laws show that changes in configuration can alter internal response capacity. The analysis of Gauss’s law distinguishes the charge–field consistency constraint from the relations preserving it during evolution and clarifies the independent role of field data in determining responses. Accepting basic relations, these studies identify the contributions of properties, states, and dynamics to explaining specific regularities. Repeatability also distinguishes laws from conditions selecting historical situations. The equivalence of dynamical and history-based representations of an oscillator, with complete response information retained, shows that the direction of deriving consequences does not by itself establish the direction of grounding. Thus, the constraint content of laws is compatible with grounding regularity in systems themselves, and the fundamental priority of modal structure is not necessary to explain the cases examined.