抄録
The Da ban niepan jing 大般涅槃経 is based upon a two-cause theory of buddha-nature-zhengyin 正因 and yuanyin 縁因 (=liaoyin 了医), as acknowledged by most scholars during Tiantai Zhiyi's 天台智〓 time. Whereas, Zhiyi advances the amalgamation of three aspects-zhengyin foxing 正因仏性 (buddha-nature of a primary cause), liaoyin foxing 了因仏性 (buddha-nature of a cause to complete one's sense), and yuanyin foxing 縁因仏性 (buddha-nature of a subsidiary cause)-collectively referred to as sanyin foxing 三因仏性 (theory of buddha-nature in three causes). Zhiyi confers central importance to the unified theory of li 理 (the law of nature), zhi 智 (wisdom), and 行 xing (training), upon which other themes such as the theory of Buddha's body, enlightenment, nature, and ascetic practices can be discussed. His buddha-dhatu theory is thoroughly covered in the Fahua xuanyi 法華玄義, and is further organized, enriched, and consummated in the Weimo jing wenshu 維摩経文疏. However, We must note that Zhiyi probably had no access to any annotated commentaries explaining the Niepan sutra, thus precluding any motivation to necessitate a detailed comparison with the Niehnan sutra.
Zhiyi's disciple, Guanding 潅頂, would write the commentaries, Xuanyi 玄義 and Wenju 文句, on the Niepan sutra after Zhiyi's death. Guanding's Neihpan xuanyi 涅槃経玄義, however, does not make reference to Zhiyi's three-cause buddha-nature theory. And, although much attention is laid within the introductory chapters of Guangding's Niepanshu 涅槃経疏 upon the three-cause theory of buddha-nature in his discussion of the three virtues in embracing one's ruler, master, and parent from the standpoint of Zhiyi's three central themes, this marks the limit of its mention. Thereafter, Guanding only advocates a two-cause theory of buddha-nature. Guanding stood on the fringe between both the text of the Niepan sutra and of Zhiyi's three-cause buddha-nature theory and did not attempt to dissolve discrepancies. This may have posed a problem for Guanding, as it is also visible in his approach of seemingly continuing Zhiyi's conception of sanshen 三身 (three-bodies of the Buddha)in accounting for the commentaries on the Eternity chapter of the Lotus Sutra 法華経, while in actuality, rendering a two-body conception of Buddha.
