Shigeki Moro

We can find some of the works of Indian Buddhist philosophers that prove the authenticity of the Mahāyāna sutras within Sanskrit, Tibetan, and Chinese textual sources. *Jayasena’s critique of *Asvabhāva’s proof was first introduced in the commentaries of Kuiji. Numerous references to *Jayasena in Chinese Yogācāra scriptures indicate that he was regarded as a Yogācāra master. His revised proof was further revised by Xuanzang. According to Xuanzang’s biographies, *Jayasena was an Indian lay Buddhist scholar who had many non-Buddhist disciples. It is, therefore, possible that he discussed the authenticity of the Mahāyāna sutras with his disciples. Following Kuiji’s introduction of *Jayasena’s proof in East Asia, this proof and Xuanzang’s critique have been widely discussed. Wonhyo, one of the most famous Silla Buddhist scholars, critiqued Xuanzang’s revision and published his revised formula. Zenju, a representative Yogācāra master of the Nara period, pointed out some logical problems to be seen in Wonhyo’s revision, but did not provide any alternative. Proof of the authenticity of the Mahāyāna sutras was originally developed as a result of interactions between Mahāyāna and non-Mahāyāna Buddhists. However, the purpose of the proof seems to have shifted from being based on arguments with actual opponents to internal discussions among Mahāyāna Buddhists, especially within East Asia.

Although the tradition of the Buddhist logic in India had been developed through the debates with non-Buddhists, that in pre-modern Japan hardly had such experiences. The applications of inmyō were limited to the disputes between the Hossō school (Japanese transmission of Yogācāra school) and another Buddhist schools. During the rapid modernization and westernization after the Meiji restoration, however, Buddhist logicians also encountered the non-Buddhist cultures including the deductive and inductive logics, Christianity, democracy and republicanism imported from Western countries. A part of them, such as Kira Kōyō, regarded inmyō as useful for the democratic discussion, and promoted it to the politicians and the legal professionals. Their introductory books about inmyō included many sample expressions which criticized the existence of God and the authenticity of republicanism, as well as the unequal treaties forced by Europe and America. In spite of those efforts, inmyō did not become popular in modern Japan. In addition, it also lost the scholars' interest in the twentieth century, because of the introduction of the scriptures of Indian logic in Sanskrit and Tibetan. But the inmyō studies in Meiji period should not be ignored, since they were regarded not only as one of the intellectual refutations to the West in East Asia, but also as the previous researches which were studied by East Asian scholars of the Buddhist logic.