從湛然〈十不二門〉論天台思想之發展演變

湛然的〈十不二門〉一文，是一篇相當精簡的短文，在此一短文中，收攝了天台智者大師《法華玄義》中「迹門十妙」之要義，乃至「本門十妙」等皆包含在內，甚至天台智者《摩訶止觀》之「一念三千」亦被加以運用之，以作為湛然理論思想之依據及觀法之所在。由此可知，〈十不二門〉所涉及層面之深廣（含括了《法華玄義》與《摩訶止觀》），統攝了天台教觀之內容。亦由此可知，〈十不二門〉於湛然思想中所扮演之重要性。正因為〈十不二門〉所扮演角色之特殊，至宋代時，天台宗諸大師對此文投以相當之關注，紛紛為〈十不二門〉作注疏，在中國已留傳下來之注疏有六種，亦有諸多注疏已佚傳。而所注疏之觀點存在諸多之不同，甚至形成對峙之局面（如山家、山外），以及仁岳對其師知禮論點的反駁。諸如此類，可看出〈十不二門〉對宋代天台學之影響，和宋代天台學所呈現的多面性、豐富性。雖然有諸多的因素導致宋代山家、山外之論諍，其關鍵恐怕還在於湛然以一念三千理具思想來詮釋天台智者的思想所致，尤其是象徵湛然思想的〈十不二門〉，往往成為爭論之對象。因此，本文直接從〈十不二門〉入手，來探討唐、宋天台學所呈現的面貌。本文主要就三方面來論述︰首先，分析〈十不二門〉的內容；進而就天台智者之《法華玄義》來理解〈十不二門〉；最後，探討〈十不二門〉對宋代山家與山外的影響。由本文的探討中，可以得知湛然是以一念三千理具思想作為其〈十不二門〉的理論基礎，以此收攝十妙作為觀法之大體，闡述十門不二之道理。然而，天台智者以即空、即假、即中之辯證張力所彰顯的一念三千，至湛然時已轉化成一念理具三千，以凸顯理具為天台之特色，同時也埋下了宋代天台學之爭端。在知禮時，更是強調理具為圓教之特色，另立「別理隨緣」，以明別理雖隨緣，然因不談理具，所以仍舊是屬別教。此理具思想雖為後來的仁岳及從義所評破，但因勢寡不敵眾、及大環境使然，且未能徹底從即空、即假、即中之辯證張力入手，終究功虧一簣。

關鍵字

十不二門；一念三千；理具

並列摘要

Chan-jan's (湛然) article Ten Non-dual Doors (〈十不二門〉) is an extremely concise essay. It Contains Master Chih-yih's (智顗) doctrines such as the ten wonders of the ＂ phenomenal ＂ door and ever ＂ noumenal ＂ door in Fa Hua Hsuen Yih(《法華玄義》) , the concept of ＂ trilicosm in one thought ＂ in Mo Ho Chih Kuan (《摩訶止觀》) , ect. Based on these doctrines, it develops into the foundation of Chan-jan's thought and method of meditation. From this, one may understand that Ten Non-dual Doors covers a very wide and profound area, and consists of Tien-tai School's doctrine and meditation method. Also, one may know well the importance of the article in Chan-jan's thought. Only because of the particular importance of this article, the different masters of Tiem-tai School in Sung Dynasty paid very much attention to it. They wrote commentaries on it. Now, six commentaries still exist although many have disappeared. The different commentaries hold many different views. Even confrontation (for example, between ＂ shan chia ＂〔山家〕 and ＂ shan Wai ＂〔山外〕) emerged and Jen-yueh (仁岳) rebuted his master Chih-lih's (知禮) argument. Such examples show the impact of Ten Non-dual Doors on the Tiem-tai sudies of Sung Dynasty as well as the its plurality and richness. Although there are many factors which lead to the dispute between ＂shan chia＂ and ＂shan wai＂, the key point is probable that Chan-jan used the concept of ＂Trilicosm in one thought＂ to interpret Tien-tai Master Chih-yi's thought. In particular, Ten Nondual Doors is usually the object of dispute. In this context, this paper Ten Non-dual Doors to investigate the situation of Tien-tai studies in T'ang and Sung Dynasties. This paper can be divided into three parts. The first part analyzes the contents of the Ten Non-dual Doors. The second part discusses the Ten Non-dual Doors from the standpoint of Chih-yi's Fa Hua Hsuen Yi. The third part deals with the impact of the Ten Non-dual Doors on the ＂san chia＂and ＂san wai＂in Sung Dynasty.