The doctorinal development of the Japanese Hossō sect is based on rongishō (論義抄) which comprehensively investigate problems in the Cheng weishi lun (成唯識論). Ryōzan’s Jōyuishikiron dogakushō (成唯識論同学鈔) is particularly famous, but it has been pointed out that he compiled another rongishō named Gusō. Moreover he had a close relationship with his master Jōkei (貞慶, 1155–1213), who was the most influential monk of the Hossō sect. This is clear based on the fact that Rōzan’s Gusō was compiled with Jōkei’s permission. Thus, studies of Ryōzan’s Gusō are indispensable to elucidate the details of Yuishiki (Vijñaptimātra) doctrine in medieval Japan.
This paper compares Ryōzan’s opinion in his Gusō with Jōkei’s standpoint in his rongishō Yuishikiron Jinshishō (唯識論尋思鈔). At times Ryōzan accepts Jōkei’s views, but not always. From this we can conclude that Ryōzan’s Gusō is a rongishō compiled in close relation to Jōkei, from whom, however, it can be distinguished.
