Yan Zun’s Purport of the Laozi (老子指归) and Commentary on the Laozi (老子注), the oldest extant annotations on the classic, construct a metaphysical system centered on chaos (hundun 混沌), synthesizing the Zhuangzi to formulate a Daoist cosmology. The Purport asserts that the Way (dao 道) is rooted in “emptiness” (xuwu 虚无)—a boundless, unknowable chaos transcending distinctions of being (you 有) and nonbeing (wu 无). Emptiness constitutes the ontological foundation of the Way and Virtue (daode 道德), while “naturalness” (ziran 自然) defines their intrinsic nature. Together, dao, emptiness, and naturalness form a triadic structure, where emptiness grounds existence, naturalness governs spontaneous order. Contrasting the Zhuangzi, where order displaces chaos, Yan Zun’s cosmology posits chaos as the eternal substrate of transformation. The Way does not directly generate the myriad things but endows them with self-generating “natures” (xing 性). Guided by the purposelessness and uncertainty of emptiness, these natures manifest naturalness through non-interference (wuwei 无为). Politically, rulers must embody “selflessness” (wuwo 无我), abandoning prediction and rigid planning to align with emergent complexity. Yan Zun’s thought resonates with modern complexity theory, particularly in its emphasis on uncertainty, self-organization, and the limits of rational design. By defining naturalness as both the autonomy of things and the transcendence of fixed boundaries, the Purport critiques deterministic systems while affirming chaos as the source of vitality. This Han-era synthesis bridges the Laozi and Zhuangzi, offering a premodern paradigm for contemporary discourses on spontaneous order and nonlinear dynamics.