A Study on the Philosophy of Perfect Harmony in the Huayan School: Focusing on the Four Dharmadhātus

The philosophy of the Huayan school is founded on the dharmadhātu (法界) as its fundamental ontology, embodying the boundless truth of the cosmos and human existence. It seamlessly integrates the philosophical doctrine of the “perfect interpenetration and non-obstruction of Buddhist teachings”, while expounding the vast tenets of “principle (理), phenomena (事), wisdom (智), and practice (行),” all of which are encompassed within the comprehensive framework of the “four stages of faith–understanding–practice–realization (信解行证)”. The idea of “four dharmadhātus” (四法界), which was first systematically formulated by Master Chengguan, is considered one of the core doctrines of Huayan thought. However, contemporary scholarship has yet to provide a thorough elucidation of the relationship between the one true dharmadhātu (一真法界) and the four dharmadhātus, nor has it sufficiently addressed the notion that the four dharmadhātus are not merely a theoretical construct but also a genuine realization—a stage in the practice of spiritual cultivation. This study first explicates the conceptual significance of the four dharmadhātus, then analyzes the Huayan patriarchs’ interpretations of the one true dharmadhātu and the four dharmadhātus. It further explores the path to awakening through the interpenetration and non-obstruction of the four dharmadhātus and highlights the integration between the empirical world and the ideal world of Buddhist teachings. Ultimately, it argues that every realm and every stage within the dharmadhātu is perfectly complete and seamlessly interconnected.