本論文是在考察天台智顗的三觀思想的展開。Paul Swanson 在Foundations of T’ien-t’ai Philosophy：The Flowering of the Two Truths Theory in Chinese Buddhism（1989）中認為：智顗的三諦思想是在他之前從二諦思想發展來的。但是，在這裡所討論的三諦思想是來自《瓔珞經》，有關三觀思想則是從天台智顗自己的思索中所產生的。總之，天台智顗在初期的《次第禪門》中，對三觀思想並不怎麼所重視，只論述凡夫、外道對生死的執著，二乘對涅槃的執著；只有菩薩由於不執著兩極端，對諸法實相的認識，又能實踐濟度眾生的事業。其次，在《六妙法門》中論述：採用《瓔珞經》的「從假入空」和「從空入假」的概念，三乘（聲聞、緣覺、菩薩）共同實踐從假入空觀；菩薩又能修從空入假觀。又在《天台小止觀》中，不僅論述了「從假入空」、「從空入假」，還採納了「中道第一義觀」，把三觀對應三智和三惑。於是最後，在晚年的《法華玄義》等中，對三觀．三智．三惑再增加三諦展開論述。以上可以認為天台智顗的三諦思想是天台智顗對三觀的深刻思索所產生的。
This paper explores the development of Zhiyi's understanding of the three contemplations. Paul Swanson, in his ”Foundations of T'ien-t'ai Philosophy: The Flowering of the Two Truths Theory in Chinese Buddhism” (1989) understood Zhiyi's three truths theory as developing out of earlier Chinese speculations on the two truths theory. However, I argue Zhiyi came to formulate his three truths theory through his sustained reflections on the three contemplations deriving from the ”Yingluojing”. In other words, in his early ”Cidi chanmen”, Zhiyi argued that, whereas common beings and non-Buddhist are attached to birth-and-death and the practitioners of the two vehicles are attached to extinction in nirvāṇa, bodhisattvas are free from attachment to either extreme. In the ”Liumiao famen”, he further develops this scheme by arguing that all the practitioners of the three vehicles (śrāvakas, pratyekabuddhas and bodhisattvas) practice the ”contemplation for entering emptiness from provisional existence,” only bodhisattvas practice the ”contemplation for extering provisional existence from emptiness.” Then, in the ”Xiao zhiguan”, he creates an elaborate typology of the three contemplations, in which the three contemplations are conjoined with three forms of wisdom and three forms of delusions. Finally, in the ”Mohe zhiguan”, Zhiyi adds the three truths to this threefold triadic scheme. Hence it is apparent that Zhiyi's theory of the three truths developed out of his sustained reflections on the three contemplations.