Dao Is Two: The Ontological Foundation of Dual-Origin and Its Paradigm Shift

Since Parmenides, metaphysics in both China and the West has generally taken "unity" and "identity" as the ultimate of ontology, making "how the One generates the Two" and "how difference arises from identity" long-standing unsolvable metaphysical paradoxes. The interpretive tradition of Chinese philosophy has mostly followed Wang Bi’s path of "the One generates the Two", regarding duality as a derivative phenomenon. Based on a critique of substantialist monism, this paper proposes and systematically defends the ontological paradigm that "Dao is inherently Two": the primordial structure of Dao is not unity, but duality; "the One" is not the ontological foundation, but a representational form after the convergence of duality. The paper first diagnoses the generative paradox of monism and clarifies the logical necessity of "the Two being prior to the One". Second, through in-depth dialogue with classic texts of Parmenides, Wang Bi, Heidegger, and others, it demonstrates the theoretical advantages of "dual-origin". Third, it downgrades the inspiration from quantum mechanics from ontological claims to conceptual heuristics, achieving a philosophical reconstruction to avoid scientific overreach. Finally, it outlines the overall program of Dao-Er philosophy and clarifies its subsequent research paths. Through a diagnostic-solution argumentative strategy, this paper not only exposes the structural flaws of traditional monistic metaphysics but also provides a positive alternative ontology centered on duality.