Dual Structure and Paradigm Breakthrough: Reconstructing the Intellectual History of Dependent Origination in Sectarian Buddhism

The evolution of the theory of dependent origination in sectarian Buddhism (部派佛教) follows two logical threads: one is the debate on the ontological nature of dharmas, which drove the shift towards a “non-substantiality” (Nairātmyavāda 無體論) interpretation of dependent origination; the other is the discussion of the nature of dependent origination, which led to a shift towards a theory of unconditioned (Asaṃskṛtavāda 無為論). On the ontological nature of dharmas, the Sarvāstivāda (有部), rooted in the doctrine of “substantial existence in three times” (Trikāla-dravyāstitva 三世實有), established a “substantial dependent origination” (有體緣起論), arguing through three principles: self-nature inclusion (自性攝), substance without function (有體無用), and the real existence of causes and conditions (因緣實有). In contrast, schools such as the Mahāsāṃghika (大眾部), Dārṣṭāntika (譬喻師), and Sautrāntika (經量部) introduced theories like the “simultaneous arising of two minds” (二心俱生), “cognition having no object” (緣無境), and “seed-function”, propelling the shift towards a theory of non-substantialism. Concerning the nature of the law of dependent origination, the Sarvāstivāda asserted that “dependent origination is conditioned”, while the Vibhajyavāda (分別說部) pioneered the notion that “dependent origination is unconditioned”, abstracting the law of dependent origination from the phenomenal world into a transcendental existence, initiating a shift towards a theory of unconditioned and giving rise to two interpretative paths: one is the Mahāsāṃghika’s “intrinsic nature of the links of dependent origination” (緣起支性), leading to the construction of the “relational unconditioned” (關係性無為); the other is the Mahīśāsaka’s (化地部) “dependent origination as suchness” (緣起真如), leading to the construction of the “principle-based unconditioned” (理體性無為). The deep interaction of these two turns not only propelled the diverse development of sectarian Buddhism theories of dependent origination but also provided theoretical prototypes for Mahayana Buddhism’s (大乘佛教) theories, such as the theory of “dependent origination under ultimate reality” (實相緣起), “suchness-based dependent origination” (真如緣起), and “innate pure mind dependent origination” (自性清淨心緣起).