Abstract This paper distinguishes existence from appearance and formalizes appearance as the encounter between possibility and a constraint boundary. Existence itself is not directly describable; it is accessible only as possibility. Appearance occurs when possibility meets a constraint boundary—universal (physical laws) or historical (accumulated relational encounters). This framework accepts Prideaux's (2025, manuscript under review at Noûs) transcendental constraint ontology as its foundation and extends it in three directions: by explicitly distinguishing existence from appearance, by introducing the temporal directionality absent from Prideaux's static account, and by connecting the philosophical argument to measurement. The framework proposes that historical constraint accumulates multiplicatively as the geometry of possibility space—tracked by KL divergence from uniformity and Participation Ratio of eigenvalue distributions. The result is an empirically tractable ontology: a philosophical argument that makes predictions about what should be measurable if it is correct, and that stands to be challenged if those predictions fail.
Kimiyasu Igarashi (Sat,) studied this question.