From the Great Void to Moral Practice: Ira Kasoff’s Systemic Reconstruction of Chang Tsai’s Ontological Ch’i in Cosmology, Human Nature, and Sagehood

This paper examines Ira E. Kasoff’s systemic interpretation of Chang Tsai’s Neo-Confucianism in his The Thought of Chang Tsai (1020–1077), focusing on Kasoff’s reconstruction of Ch’i (qi, 气) as the ontological foundation of Chang’s philosophy. Through a trichotomous translational strategy—distinguishing between “Ch’i”, “ch’i”, and “qi”—Kasoff systematically integrates Chang’s cosmology, human nature, and ethics into a coherent framework. He argues that Ch’i (e.g., Great Void, taixu, 太虚) serves as the primordial substance underlying all existence, while ch’i and qi explain the generation of phenomenal forms and moral agency. Kasoff highlights how Chang’s Ch’i-centric ontology refutes Buddhist illusionism and Daoist non-being, positing yin–yang interactions as the self-generative mechanism of the cosmos. Central to Kasoff’s analysis is Chang’s dual-nature theory of heavenly nature (天地之性, as the inherent goodness of Ch’i) and physical nature (气质之性, as the individualized limitations of ch’i); Kasoff demonstrates how Chang’s emphasis on learning (xue, 学) aims to transform nature and restore heavenly nature, culminating in sagehood as the realization of cosmic harmony. Additionally, by contrasting Chang’s Ch’i-based system with Cheng-Zhu Neo-Confucianism, Kasoff underscores its originality—a dynamic, materialist ontology that bridges metaphysics and ethics.