Although the Huayan fivefold system of doctrinal classification is representative in Chinese Buddhism, questions have been raised historically. These questions are of two types. First, it is suspected that Huayan’s classification of “Five Teachings” simply imitates the Tiantai classificatory system. Second, the establishment of Mahāyāna sudden teaching is criticized as lacking a reasonable basis. Regarding these questions, fourth Huayan patriarch Chengguan attempted to provide a discussion and resolution. However, he could not get to the core of the issue, and his position was unable to provide a strong theoretical defense in support of the Huayan Five Teachings. This paper focuses on the question of the reasonableness of the Huayan system of classification through an analysis of the true meaning of the Huayan system, with the aim of clarifying various misunderstandings found in common interpretations. This will serve to show the unique theoretical value of the Huayan system, bringing a new understanding and evaluation of the innovative significance of Mahāyāna tathāgatagarbha thought.
