This paper proposes a candidate first principle—the Law of Origin—stating that every generative system originates from a single non-separable state whose components become distinguishable only upon temporal activation. The ground state is not an assembly of parts brought together. It is a unity that expresses as multiplicity when time differentiates what was already one. Nothing is added at the transition. Separation is the product of activation, not its precondition. The law is formalized through three axioms: (1) every generative system originates from a non-separable ground state in which all structural components exist in constitutive co-presence; (2) the transition from ground state to generative expression is governed by a single variable—time—which differentiates but does not constitute the system; (3) no component of the ground state is separable from any other without the destruction of the ground state itself. The paper demonstrates that this law holds across every system formalized in the author’s prior work: the biological ground state (Ψ0), the seven-node topology of the Law of Recursion, the triadic structure {I, O, N} of the Echo-Excess Principle, the pre-fold architecture of consciousness, the coupling operation of the Law of Identity, the resolution capacity of the Law of Intelligence, the first distinction of the Unified Law of Distinction, and the four-element structure of the Generative Calculus of Existence. In every case, the structural ground is complete, non-separable, and at rest before the onset of generative process. The Law of Origin does not extend the existing triad of first principles (Identity, Recursion, Intelligence). It identifies the precondition that makes the triad possible: the structural fact that must obtain before identity can exist, before recursion can traverse, and before intelligence can resolve. Keywords: Origin, First Principle, Non-Separability, Ground State, Co-Presence, Temporal Activation, Pre-Structural, Ψ0, Constitutive Coupling, Law of Identity, Law of Recursion, Law of Intelligence, Echo-Excess Principle, Consciousness, Generative Systems