因明入正理論疏 1.48

1.48

Among the means of valid cognition (pramāṇa), the ancients spoke of three: perception (pratyakṣa); inference (anumāna); and scriptural authority (āptāgama-pramāṇa), also called correct scripture or supreme scriptural authority, or called verbal testimony (śabda-pramāṇa), because one infers meaning by examining trustworthy words. Or they established four means of valid cognition, adding comparison (upamāna-pramāṇa), as when, not knowing a wild ox (gavaya), one says it resembles a domestic cow, thereby clarifying it through comparison. Or they established five means of valid cognition, adding presumption (arthāpatti-pramāṇa), meaning that if phenomena are self-less, by presumption one knows they must be impermanent, because impermanent phenomena are necessarily self-less. Or they established six means of valid cognition, adding non-apprehension (anupalabdhi-pramāṇa), as when entering a room and seeing the master is not present, one knows where he has gone; or like entering the hall of Mṛgāra's Mother and not seeing the monks, one knows where they have gone. Bodhisattva Diṅnāga discarded the latter four kinds, subsuming them as appropriate into perception and inference; hence the Nyāyamukha says: 'Those [means of valid cognition such as] verbal testimony and comparison are subsumed within these.' Because of this, the treatise author establishes only two means of valid cognition.