Tiantai Zhiyi’s most complete philosophy of the threefold truth and threefold contemplation is considered to have been formed during the period of the Three Major Treatises 三大部 （Mohe zhiguan 摩訶止觀 [T 1911], Fahua xianyi 法華玄義 [T 1716] and Fahua wenju 法華文句 [T 1718]; 585-594） after his descent from Mount Tiantai. However, Guanding’s 灌頂 Guanxin lunshu 観心論疏 （T 1921）, which is a commentary on Zhiyi’s Guanxin lun 観心論 （T 1920）, indicates that different forms of the threefold truth and threefold contemplation were practiced during the period of the Three Major Treatises. This all occurred after Zhiyi exposed the Three Major Treatises during the last years of his life （595-597）. Therefore, through a comparative study of the threefold contemplation in the Guanxin lunshu and the Sanguanyi 三観義, which were written at about the same time, this essay will clarify that the current threefold truth and threefold contemplation of the Three Major Treatises are based on the thought of Zhiyi in his final years.
