Chih-i’s writings contributed two important elements to Saichō’s thought on the precepts. First, Chih-i’s concept of a bodhisattva who performed Sudden practices was a forerunner of Saichō’s association of the Fan wang precepts with the Direct Path (jikidō) to enlightenment. Secondly, Chih-i’s use of the term ‘Perfect precepts’ (enkai) suggested that certain precepts were suited for those who followed the Perfect teachings of the Lotus Sūtra and that those precepts might be distinct from the Hinayāna precepts.

Chih-i’s position on the precepts differed from that of Saichō in several ways. First, Chih-i advocated the harmonious combination of the Hinayāna and Mahāyāna precepts. Even when the precepts were realized through Sudden practices, they still encompassed the Hinayāna precepts. Secondly, Chih-i’s concept of the Perfect precepts was abstract. He did not identify the Perfect precepts with a specific set of rules. The Fan wang precepts represented a mixture of Unique and Perfect teachings, not solely Perfect (jun’en) teachings. The purely Perfect precepts could only be observed by the Buddha. Before the doctrinal foundation for Saichō’s proposals would be complete, the Perfect precepts would have to be identified with the Fan wang precepts and freed of the onus of incorporating Hinayāna or Unique teachings.