本文嘗試回歸印度佛學思想史的發展脈絡，分析《大般涅槃經》中「常樂我淨」觀在修行見解與解脫境界兩重面相的意涵，並探討經典如何安置「佛性」說作為見解與境界綰合的樞紐。首先，在見解層面，《大般涅槃經》論「常樂我淨」是與「四顛倒」的錯見形成對立，其中包含凡夫與小乘兩個層次，經典對此表示明確的排斥立場；其次，在境界層面，「常樂我淨」在經文中是作為解脫、涅槃境界的狀態，且與中觀學派「實相涅槃」的觀點相通，但差別處在於《大般涅槃經》對涅槃境界採取正面肯認態度，即認同解脫與涅槃的實存意義，中觀學說則秉持「空空」的主張，對於解脫、涅槃始終採取否定遮詮的方式；最後，《大般涅槃經》提出「佛性」之說，透過「佛性」兼具成佛果位及修行因位的特點，貫通見解與境界可能產生的落差，並由此建構出《大般涅槃經》獨特的學說主張

The thesis is an attempt on two sides: one is returning to the development of India Buddhism to analyze the thought of ＂Nitya-sukha-atma-subha,＂ which has the following two meanings in the Nirvāṇa Sūtra: the concept of practicing Buddhist and the state of renunciation in Buddhism. The other attempt is to discuss how the Buddha nature in the Nirvāṇa Sūtra could be both a concept and a state. As a concept, the discussion on ＂Nitya-sukha-atma-subha＂ is contrary to the point of ＂Viparyasa-catuka＂ in the Nirvāṇa Sūtra. The mistake of ＂Viparyasa-catuka＂ is including two gradations between ＂Prthag-jana＂ and ＂Hinayana,＂ but the classics stands on the negative way. As a state, the point of ＂Nitya-sukha-atma-subha＂ is not only regarded as a situation about ＂renunciation＂ or ＂the state of Nirvana＂ in the Nirvāṇa Sūtra, but also as interlinking the view of ＂the reality of Nirvana＂ supported by the Madhyamaka. However there are still some differences between the Nirvāṇa Sūtra and Madhyamaka: the former has a positive attitude towards the state of Nirvana, that is to say, the Nirvāṇa Sūtra identifies with the hypostatic meaning between ＂renunciation＂ and ＂Nirvana,＂ but the latter doesn't. Rather Madhyamaka keeps the same opinion on ＂kong-kong.＂ Finally, in order to understand thoroughly the level of concept and state, the Nirvāṇa Sūtra discusses the idea of Buddha nature, which has the characteristic of ＂the situation of Buddha＂ and ＂the condition of being Buddha.＂ This represents a unique theory