On the Scale Approximability and Cognitive Boundary of Causality

Modern physics has long held two opposing extreme viewpoints. Laplacean omniscient determinism states that once all initial conditions of a system are mastered, every future evolution state can be deduced. The intrinsic randomness interpretation in quantum mechanics attributes phenomena that cannot be precisely predicted to inherent randomness at the fundamental level of the universe. Based on the pure theoretical logic of bidirectional dynamic coupling among variables, this paper carries out analysis and argumentation. It proves that the universe strictly obeys the law of causality, and the objective evolution outcome possesses unique determinacy. System variables continuously interact and rewrite the states of one another in real time. This characteristic theoretically excludes the possibility of omniscient prediction. This paper endorses the core proposition of Einstein’s causal realism, distinguishes objective causal determinacy from the theoretical boundary of deductive capability. It points out that the quantum probability interpretation confuses cognitive limitation with the intrinsic property of matter. It also explains the resource tradeoff logic of approximate models in practical applications, and establishes a unified and self consistent framework for understanding causality in fundamental physics.