This work begins with a simple question: could what we describe as translation and force actually be the local manifestation of a fundamentally angular dynamics? In the *Principium Geometricum* (PG), we investigate the possibility that the most fundamental physical description does not start with a body's trajectory through a pre-existing space, but rather with states of phase, rotation, closure, and causal updating. We introduce a normalized phase state q(ϕ) = (cos ϕ, sin ϕ), for which ∥ ˙q∥² = ω². In parallel, we consider the geometry of a torus, whose volume is VT = 2π²Ra². In the reduced geometric case where R = a = r, we have VT = 2π²r³. These two structures suggest the quantity IT ≡ VT 2π² ∥ ˙q∥² = r³ω². We propose investigating the conservation of IT for orbital states associated with the same global source. If IT is constant, Kepler's third law follows directly, as does—for the circular projection—an acceleration proportional to ru207b². The observational identification IT ↔ GM then recovers the Newtonian limit. This result does not constitute a microscopic derivation of gravity. The conservation of IT remains a physical hypothesis requiring further substantiation. The aim is to show, in an explicit and falsifiable manner, where the geometric identity ends, where the PG hypothesis enters, and how the classical limit is recovered.