再考：ディグナーガのpakṣābhāsa説――PS III 2b²–d¹の読み方――

抄録

Dignāga established a theory of pakṣābhāsa (fallacious thesis) in relation to the definition of pakṣa (thesis). In his Pramāṇasamuccaya (PS), he states:

... anirākṛtaḥ / pratyakṣārthānumānāptaprasiddhena ... // 2 // (PS III 2b²–d¹)

[A property to be proved (sādhyadharma) should] not be opposed by “pratyakṣārthānu-mānāptaprasiddha.”

Dharmakīrti, in his Pramāṇaviniścaya, inteprets the word pratyakṣārthānumānāptaprasiddha of PS as a dvandva compound of the four component words: pratyakṣārtha, anumāna, āpta, and prasiddha, and understands that the last word prasiddha means śābdaprasiddha. Jinedrabuddhi, a commentator of PS, adopts Dharmakīrti’s interpretation.

On considering Dignāga’s own explanation in his own commentary (Pramāṇa-samuccayavṛtti, PSV) on this part of the verse, however, the word can be interpreted as a compound of three component words: pratyakṣārtha, anumāna[-prasiddha], and āptaprasiddha. Dignāga explains that when a sādhyadharma stated in a thesis is opposed by another dharma/atha which is already established (prasiddha) by some valid means, such a thesis should be regarded as a fallacious thesis (pakṣābhāsa). Accordingly, the word prasiddha should not be separated to solely mean śābdaprasiddha.

Intriguingly, Dharmakīrt’s followers mention and criticize such a different interpretation. Śākyabuddhi attributes this interpretation to some commentator (s) of PS (*Pramāṇasamuccayaṭīkākāra), who cannot be identified with Jinendrabuddhi. The interpretation which seems to correspond to Dignāga’s intention has never been supported by Dharmakīrti’s followers, including Jinendrabuddhi, and as a result it was consigned to oblivion.

Dharmakīrti’s interpretation of Dignāga’s PS/PSV must be useful for understanding the words of PS/PSV. But it should be noted that Dharmakīrti’s interpretation does not necessarily correspond to Dignāga’s own intention.