This dissertation examines the founding Chinese masters of the Japanese Obaku school, Yinyuan Longqi (1592-1673), Muan Xingtao (1611-1684), Jifei Ruyi (1616-1671), and Gaoquan Xingdun (1633-1695), and their impact on Edo Rinzai Zen. All four figures spent their formative years in China and were active in the late Ming/early Qing period religious sphere, yet their most lasting and significant contribution to East Asian Buddhism remains in Japan, where they founded the Ōbaku school. By the mid-seventeenth century the Japanese Zen world had gone nearly four centuries without marked contact with continental models. Koan practice in Rinzai and Sōtō Zen had become largely fossilized, and there was little in the way of innovation as a whole. When Yinyuan brought Ming-era Zen Buddhism to Japan, it provided the impetus and challenge that Japanese Zen needed to reassert and redefine itself.
Of all the assets that the Ōbaku monks possessed, perhaps the most important for their success in Japan was their Chinese background. China retained its cultural prestige well into the Edo period, and since the Ōbaku monks were custodians of a Chinese form of Buddhism, a significant section of Japanese Zen viewed the Chinese monks with an unquestioned legitimacy. In order to understand the Ōbaku monks in Japan, it is necessary to consider their background in China, therefore this dissertation investigates both the political conditions of contemporaneous China, as well as the personal history of each Chinese master. In addition, the proponents of the Ōbaku Zen style enthusiastically received its emphasis on monastic discipline, while Ōbaku's opponents criticized its Zen as a corrupted form of Pure Land Zen based on the Ōbaku practice of chanting the Buddha's name (nenbutsu ) within the monastic setting. This study looks in particular detail at these two aspects of Ōbaku practice---monastic discipline and the nenbutsu---to see what the Ōbaku masters themselves had to say on these two issues that came to conspicuously define their practice. The dissertation will also examine mortification practices in the Ōbaku school, one of its lesser known aspects. After looking at how the early Ōbaku masters understood and utilized the tradition, the dissertation will examine the Ōbaku shingi, the monastic code that was established to regulate monastic practice at the head monastery, Manpukuji. Finally, consideration will be extended to how Ōbaku models were absorbed by Kogetsu Zenzai (1667-1751) and his disciples, eventually only to be overwhelmed by Hakuin Ekaku's (1685-1768) line, which then went on to become the dominant one of Edo, and therefore modern Rinzai Zen.
