We present a foundational framework for physics based on a single circle-valued phase field, Phi, defined on a minimal event domain X. The domain X is modeled as a smooth manifold without any presupposed spacetime, metric, or causal structure. The framework introduces a Pure Phi Language equipped with four formal firewalls—Well-Formedness, Invariance, Domain/Guard, and the Non-Encodability Challenge—which restrict admissible statements to those expressible solely in terms of the phase field Phi, its local real-valued lifts, finite derivative data, their differentials, excised domains, and topological invariants. Within this language, we establish three core results. First, Necessity: any coherent, predictive, and shareable physical theory must presuppose a primitive notion of comparability, formalized here by the phase field Phi. Second, Finite Data Representational Capacity: for any finite set of experimental data produced or predicted by a physical theory, there exists a Phi-based representation capable of encoding that data within specified experimental tolerances. Third, Falsifiability: the framework is falsified either by the construction of a complete physical theory that operates without any distinction or comparison concepts, or by the discovery of an operationally defined observable that distinguishes configurations related by global phase redundancy. The framework demonstrates how discrete physical structure arises without being postulated, showing that topological quantization follows inevitably from the global structure of a circle-valued phase field. In particular, integer-valued invariants such as winding numbers and holonomy classes emerge as necessary consequences of global consistency. These results provide a mathematically rigorous foundation from which spacetime geometry, matter-like structures, and dynamics may be reconstructed under explicitly stated additional assumptions. The framework yields concrete, testable implications, including the integer-valued nature of phase holonomy integrals and experimentally accessible consequences of phase-field relationalism.