「頓悟成佛」乃是《六祖壇經》所提出革命性的佛學宣言，亦為六祖以後禪宗僧眾普遍信奉的禪法宗旨。然而，沿波討源，竺道生、謝靈運乃是這個觀點的重要源頭，故而本文擬以竺道生「阿闡提人皆得成佛」之說及謝靈運〈辨宗論〉為主軸，論述這個重要時代的佛學思想。《大般涅槃經》乃是「眾生皆有佛性」最重要的經典依據，然而，由於版本的不同，卻對「一闡提究竟有沒有佛性」這個問題產生出完全相反的觀點。於此，筆者暫探《大般涅槃經》並不是一時一人一地所出觀點，從接受者來看竺道生及當時僧眾所接受到的訊息，證明竺道生《佛性論》所看到的《大般涅槃經》都是前半、後半不同的佛性觀點，故而，竺道生以玄學「言意之辨」觀點突破《大般涅槃經》文本觀點，並以「權」與「常」來調合「一闡提有沒有佛性」問題的矛盾說法，終而推論出「阿闡提人皆得成佛」之說。相較於竺道生，謝靈運〈辨宗論〉則另闢蹊徑。不但從「孔釋折中」解說「頓悟成佛」 觀點，更提出了比竺道生更前衛的觀點，而且如湯用彤《漢魏兩晉南北朝佛教史》所言「其作用不啻在宣告聖人之可至，而為伊川謂『學』乃以至聖人學說之先河」，展現了中國思想史上無可取代的價值。雖然竺道生、謝靈運於中國佛教發展史上均具有關鍵性的特殊地位，但二者卻享有完全不同的待遇，讓我們不得不訝異中國佛學發展道路真是到處充滿「偶然」！

Attaining Buddhahood through satori (頓悟成佛) is the revolutionary proclamation of the Platform Sutra of Sixth Patriarch (六祖壇經) and the acknowledged practice of Zen Buddhism after its widespread recognition. Yet it is Zhu Daosheng and Hsieh Ling-Yun that provided earlier sources of this concept. Based on Zhu Daosheng's icchantika's potential to attain Buddhahood (阿闡提人皆得成佛) theory and Hsieh Ling-Yun's Bian Zong Lun (辨宗論), therefore, the present study will deal with the Buddhist philosophies of the era in which these two documents were accomplished. Mahā-parinirvāna Sūtra is the most important basis of the concept "every living being has buddhata." But different versions of this Sutra lead to totally contradictory viewpoints regardiog the question of whether or not icchantika possesses buddhata. It may tentatively be argued that Mahā-parinirvāna Sūtra was not written by the same person, during the same period, and in the same region, and that Zhu Daosheng's and Fo Hsing Lun(佛性論) tended to be alert to the conflicting contentions in Mahā-parinirvāna Sūtra. Zhu Daosheng applied the metaphysical method of differentiating between meaning and speech (言意之辨) and mediated the contradictory viewpoints on the possession of buddhata. With the concepts of temporality (權) and constancy (常), Zhu Daosheng ended up with the assertion that icchantika can also become Buddha. By contrast, Hsieh Ling-Yun's Bian Zong Lun developed another approach. He employed what we may call a negotiation between Confucianism and Buddhism to explain the concept of satori and brought about ideas more advanced than Zhu Daosheng's. As Tang Yongtong (湯用彤) noted in The Buddhist History of Wei, Jin, and North and South Dynasties," Hsieh Ling-Yun's contribution was no less than proclaiming that the attainment of sainthood can be guaranteed, and in this regard he may anticipate Cheng Yi's (程頤) theory of learning to become a saint." Thus Hsieh Ling-Yun demonstrated his irreplaceable value in the history of Chinese philosophy. Although both Zhu Daosheng and Hsieh Ling-Yun take a crucial role in Chinese Buddhism, they have received completely different appraisals. This is the issue I term as the contingency of the evolution of Chinese Buddhology.