摘要
本論文探討智顗所創立之圓頓止觀法門，研究主題包括其學說思想、實踐方法與修證位次。論述主軸在於研究天台圓頓止觀之具體行法與學說特色。
首先探討智顗一生行道之經歷與證量，以作為研究天台圓頓止觀法門之基礎。發現智顗一生之修道歷程，正符合天台修道階次中的「觀行即位」（「五品第子位」中的五個過程）。
其次從天台圓教的勝義出發，依觀法、解脫與佛果等三個角度，說明圓教之特色與圓教止觀的修行特義。
進而全面探討智顗的三部主要止觀著作：《釋禪波羅蜜次第法門》、《六妙法門》與《摩訶止觀》。其中《摩訶止觀》是建構「圓頓止觀」的巨著，闡發天台圓教的不次第止觀，至極圓頓的觀心法門。在天台主要的止觀修行法要中，本部論文特舉「廿五方便」、「四種三昧」、「法華三昧」、「十乘觀法」等內涵而作詮釋分析。
在以上三項研究的基礎上，進一步討論天台「觀心法門」之特義與殊勝，以剖析智顗安立天台「六即佛位」與「四種佛土」的義涵，並提出個人觀點，認為智顗晚年念佛往生西方淨土，有其圓教學理根源的，以此回應學界與淨宗學人對智顗的否定與質疑。
最後，更依圓教「不斷、斷」之修行理則，總結智顗以「觀行五品」為因，六根清淨之「相似即位」為果的階段性修證意義。

Synopsis
This thesis investigates the Complete and Immediate Practice of Concentration and Contemplation founded by Venerable Zhi-yi. Topics of research include investigating his ideology, methods of practice and classification of stages of cultivation and attainment. The main focus of the thesis is to analyse the actual ways of practice and the uniqueness of the theory of this Complete and Immediate Practice of Concentration and Contemplation of the Tian-tai school.
Firstly, this thesis studies Venerable Zhi-yi’s journey of practice and attainment throughout his life. This sets the foundation for further investigation into the Tian-tai school’s Complete and Immediate Practice of Concentration and Contemplation. This thesis illustrates how Venerable Zhi-yi’s journey of practice throughout his life is in accordance with the ‘Contemplation and Practice Stage of Realisation’ (the five processes in the practice of the ‘Five Levels of Practitioners’), in the Tian-tai’s classification of stages of cultivation.
Secondly, by setting its foundation on the supreme truth of the Tian-tai school’s Complete Teaching, and from the perspectives of way of contemplation, liberation and attainment of Buddhahood, this thesis explains the uniqueness of the Complete Teaching, and the significance of the Complete Teaching’s practice of concentration and contemplation.
Then, the thesis goes on to study Venerable Zhi-yi’s three major writings on cultivation of concentration and contemplation. They are: An Explanation on Stages of Practice of Meditation Paramita (Shi Chan Bo Luo Mi Ci Di Fa Men), The Six Subtle and Magnificent Practices (Liu Miao Fa Men), The Great Practice of Concentration and Contemplation (Mo He Zhi Guan). Among them, The Great Practice of Concentration and Contemplation is the major writing that constructs the teaching of the Complete and Immediate Practice of Concentration and Contemplation. It expounds the non-sequential meditative practice of the Complete Teaching in Tian-tai, and the utmost comprehensive and immediate practice of contemplating the mind. Among the major practices of the Tian-tai school, this thesis highlights and provides explanations and analysis on the cultivation of the ‘Twenty-five Skilful Means’, the ‘Four Types of Samadhi’, the ‘Fa-Hua Samadhi’, the ‘Ten Ways of Contemplation’ and many more.
Based on the three studies mentioned above, this thesis goes a step further into discussing the significance and specialty of Tian-tai’s method of contemplating the mind. With this discussion, it analyses the meaning of the ‘Six Stages of Realisation to Buddhahood’ and the ‘Four Types of Buddhaland’ as expounded by Venerable Zhi-yi for the Tian-tai school. The author propounds that Venerable Zhi-yi’s turning to recollection of the Buddha’s name, and his vow to be reborn in the Western Pureland at his later age, is related to his theory of Complete Teaching. This view is in response to doubts and rejections that some Pureland practitioners and scholars have about Venerable Zhi-yi.
Finally, by upholding the Complete Teaching’s principle of practice of ‘neither connected nor disconnected’, this thesis concludes that Venerable Zhi-yi sees the significance of stages in practice. Venerable Zhi-yi sees the cultivation of ‘Five Levels of Practice and Contemplation’ as the cause, and the ‘Resemblance Stage of Realisation’ where the six sense organs are purified as the effect/fruition.