Basic Ontodynamics proposes a philosophical–physical framework in which geometry, matter, inertia, gravitation, and cosmological structure arise as emergent regimes of a minimal process ontology. The ontological core consists of three inseparable operational modes—Difference (Diff), Stasis (St), and Dissipation (Diss)—collectively termed Monos. The framework is grounded in the principle of constitutive unattainability: absolute self-identity is structurally impossible in any system that admits differentiation. From this prohibition, the triadic dynamics of Diff–St–Diss follows as a minimal ontological consequence Observable entities are interpreted as coherent activations (CoAct) of structural modes exceeding a context-dependent threshold. Mass corresponds to depth of multi scale coherence; inertia to resistance against inter-scale phase reconfiguration; motion to relational phase gradients; and gravitation to structural response to gradients in background density. Time is not posited as a primitive dimension. Temporal ordering emerges from the intensity of process actualization. Phenomena traditionally described as relativistic effects are reinterpreted as modulations of process rates. A minimal dynamical illustration explicitly realizes the Diff–St–Diss triad and demonstrates metastability, inertial delay, clustering, and orbit-like equilibria without introducing additional ontological substances.