プラジュニャーカラグプタの真理観――四諦と不二知をめぐって――

抄録

As is well known, in the Pramāṇasiddhi chapter of his Pramāṇavārttika （PV II）, Dharmakīrti defines the means of valid cognition （pramāṇa） in two ways, namely, as non-belying cognition, and as that which illuminates an object not yet known to other teachers. With regard to the second, he also asserts that the protection （tāya） of the Buddha is nothing other than the illumination of the four nobles’ truths. In his commentary on this chapter, Prajñākaragupta integrates his own view of the truth that only wisdom of nonduality （advayajñāna） remains, after rejecting any kind of dualistic notions such as cause and effect. This paper examines Prajñākaragupta’s use in various contexts of nondual wisdom to illustrate that it indicates the truth of selflessness of all entities （dharmanairātmya）. One of his most significant uses of nondual wisdom in this way is found in his interpretation of yukti in PV II 139, which he explains as the realization of non-duality （advaitadṛṣṭi）, since the term yukti in this passage means the mutual connection of all entities without distinction. Probably presupposing this interpretation, in his commentary on PV II 146ab, he also explains that despite lacking yukti, namely, dharmanairātmya, the path shown in the Buddha’s teaching of the four nobles’ truths is efficacious. What Prajñākaragupta does in his commentary is to show that the path of Mahāyāna Buddhism is based on dharmanairātmya, going beyond the position of Dharmakīrti, who did not refer to nondual wisdom but discussed rather pudgalanairātmya.