日本江戶時期不僅以各宗祖師著作為對象的宗學研究發達，佛教學的研究也極其盛行。其中，各類唯識典籍的研究也得到了發展，可惜受到當前學界的關注度仍不足。結城令聞曾將江戶時期唯識學的發展分為四期。本文研究對象戒定（ 1750-1805）屬於此四期中第三期元文至享和時期 1736-1803）的人物。結城令聞指出，這一時 期的學風更傾向於自由討究，更具批判性。戒定即是此一類型學僧的代表人物。 本文將研究的視角聚焦在戒定《成唯識論戒定鈔》一書上。《豐山全書》對該書的解題指出，戒定對於《成唯識論》的研究多有前人所未發之創見，對於唯識學的研究大有裨益。他透過對於《深密》《瑜伽》《攝論》《莊嚴》等論典的深入研究，努力把握無著、世親的神髓。又指摘護法的謬解、破斥窺基《成唯識論述記》的曲解，不佞諛相宗宗義，不受縛於玄奘一門諸師之古說，從自由討究的角度對於《成唯識論》展開注釋。本文即是以《成唯識論戒定鈔》為對象，討論所謂戒定「自由討究」學風的具體展現及其意義與價值。 During the Edo period in Japan, the study of Buddhist philosophy flourished, not only focusing on the works of various sect patriarchs but also encompassing the study of Buddhist teachings. Among them, research on various Yogācāra scriptures also made progress; however, it still lacked sufficient attention from the academic community. Reimon Yuki categorized the development of Yogācāra studies in the Edo period into four stages. The subject of this paper, Kaijou(1750-1805), belongs to the third stage named the Genbun to Kyōwa period (1736-1803). Yuki pointed out that the scholarly atmosphere during this period leaned towards free inquiry and had a more critical approach, and Kaijou was a representative figure of this type of scholar-monk. This paper focuses on Kaijou's work Jouyuishikironkaijoushou. Zoku Buzan Zensho praised Kaijou's contributions to the study of the Cheng Weishi Lun, stating that he made innovative discoveries not found in previous research and greatly benefited the study of Yogācāra. Through in-depth research on scriptures such as the Saṃdhinirmocana-sūtra, Yogācāra-bhūmi-śāstra, Mahāyāna-saṃgraha-śāstra, and Mahāyānasūtrâlaṃkāra, Kaijou strove to grasp the essence of Asaṅga and Vasubandhu's teachings. He also criticized misconceptions of Dharmapāla and refuted misinterpretations of Kuiji's Cheng Weishi Lun Shu Ji, avoiding flattery and adherence to the interpretations of the Xuanzang lineage. He approached the Cheng Weishi Lun from the perspective of free inquiry, providing annotations. This paper focuses on Kaijou's Jouyuishikironkaijoushou to discuss the specific manifestations, significance, and value of the "free inquiry" scholarly approach represented by Kaijou.
