『釈軌論』における三三昧 : 『声聞地』との比較を通じて

Despite a number of studies on samādhitraya or "the three meditations" carried out by contemporary scholars, little has been done on Vasubandhu's interpretation of samādhitraya in the Vyākhyāyukti (VyY). Therefore, the present paper aims at investigating Vasubandhu's interpretation of samādhitraya as given in VyY by comparison with those found in the other two treatises, the Abhidharmakośabhāşya (AKBh) and the Śrāvakabhūmi (ŚrBh). In AKBh, samādhitraya, consisting of śunyātasamādhi, apraņihitasamādhi and ānimitta-samādhr, is explained in relation to şodaśākārās or the "sixteen aspects" of catuhsatya This interpretation derives from the Mahāvibhāşā, which was also followed by Samghabhadra's Nyāyānusāra. Consequently, it may safely be said that the above is the Sarvāstivādin's traditional interpretation of samādhitraya. However, in his subsequent work VyY, Vasubandhu elucidates samāditraya in a slightly but significantly different way. Samādhitraya is discussed in chapter 2 of VyY, which cites 103 Sūtrakhaņdas and gives brief interpretations of them respectively. With regard to the interpretation of samādhitraya, two major differences are found between AKBh and VyY. First, in AKBh he cites a passage from Samyukta-āgama 703 in order to refute the Sarvāstivādin's *sarvakālāstitā theory; on the other hand, in VyY the same passage is quoted as an important source for confirming his interpretation of samādhitraya. Secondly, unlike in the AKBh, Vasubandhu as the author of VyY divides all things into three categories, i.e. non-existence (asat) and existence (sat), the latter being divided again into "conditioned" (samskŗta) and "unconditioned" (asamskŗta). It is interesting to note that Vasubandhu's above interpretation of samādhitraya in VyY reminds us of the explanation of trīņi vimokşamukhāni in ŚrBh, which also divides all things into existence and non-existence, and again existence into "conditioned" and "unconditioned." It is explained in ŚrBh that because of apraņihita-vimokşamukha we do not wish "conditioned" (samskŗta) elements, because of ānimitta-vimokşamukha we wish "unconditioned" (asamskŗta) nirvaņa, and because of īūnyatā-vimokşamukha we understand non-existence as such. Vasubandhu, the author of VyY, seems to have basically followed this interpretation of trīņi vimokşamukhāni as given in ŚrBh. In VyY, he interprets the passage from Samyukta-āgama 703 as dividing all things into existence and non-existence, and again existence into both "something inferior" (sottara) and "something best" (anuttara). He therein explains that because of śūnyatāsamãdhi existence and non-existence are understood as such, because of apraņihitasamādhi we do not wish "something inferior," i.e. "conditioned" (samskŗta) elements, and because of ānimitta-samādhi we wish "something best," i.e. "unconditioned" (asamskŗta) nirvāņa. The difference in Vasubandhu's interpretation of samādhitraya in VyY from the explanation of trīņi vimokşamukhāni given in SrBh is that unlike ŚrBh, Vasubandhu explains śūnyatāsamādhi prior to the other two samādhis and he appears to be the first who elucidated the reason for the order of samādhitraya, i.e.samādhi of śūnyatā, apraņihita, and ānimitta. From the above discussion, we may draw the following conclusion: (1) Vasubandhu basically follows the Sarvāstivādin's traditional order of samādhitraya, i.e. samādhi of śūnyatā, apraņihita, and ānimitta. (2) However, he seems to be the first who clarified the reason for the very order of samādhitraya and it also seems likely that in relation to the interpretation of samādhitraya he followed ŚrBh's way of dividing all things into three categories, non-existence and two kinds of existence, "conditioned" and "unconditioned.