Role Of Drstanta Indignagas Logic

Author(s): Shoryu Katsura
Publisher: Shoryu Katsura

Page 16

dissimilar example, on the other hand, should be interpreted as a simple negation (prasajyapratisedha), so that the negation of non-eternal things does not imply/affirm the existence of eternal things, such as ether (ākāśa).
Thus Dignāga concludes that the dissimilare example of Proof 2 is meaningful even for those who do not acknowledge the existence of eternal things, such as the Sautrāntikas.26 This implies that for Dignāga the dissimilar example does not necessarily need an objective support in reality, provided that there is an objective support for the similar example.
3.1. A question arises: Why the two examples are formulated in the way explained in PS IV.2 and 3? In other words, if a similar example is formulated by “A reason is followed by a property to be proved (hetoḥ sādhyenānugamaḥ)" or “Px > Qx", why a dissimilar example is formulated by "In the absence of a property to be proved a reson is absent (sādhyābhāve hetor nāstitā)" or "-Qx -Px”, not by “In the absence of a reason, a property to be proved is absents (hetvabhāve sādhyasya nāstitā) or "-Px > -Qx”? It is apparent that the law of contraposition was not known to the opponents and it is perhaps Dignāga who for the first time among Indian logicians came to realize that such a law should be applied to the formulations of similar and dissimilar examples; unfortunately, however, he does not give either name or definition of such a law.
In any case Dignāga answers to the above question: Only in that way, not in the reversed way (na viparyayāt), we can show that a reason under consideration possesses the second and the third characteritics of a valid reason; namely, “A reason's presence in a set of similar instances only (hetoh sapaksa eva sattvam)" and “Its definite absence in the absence of a property to be proved (sādhyabhāve cāsattvam eva)”. 27 Here again we see the definitive role played by the restrictive
26 PSV[K] 148b2-3: de lta na snga ma la ni ma yin pa yin la phyi ma la ni med par dgag pa yin no zhes smras pa yin no ll de Itar na rtag pa khas ma blangs kyang chos mi mthun pa'i dpe grub pa yin no // (evam ca pūrvatra paryudāsah uttaratra tu prasajyapratisedha ity uktaḥ / evam ca nityānabhyupagamasyāpi vaidharmaydrstāntaḥ siddhah) Cf. Kitagawa (19 )
27 PSV [K] 148b3-4: gal te gcig la ni gtan ts.rigs bsgrub bya'i rjes su 'gro bar bshad la / gnyis pa la ni bsgrub bya med na gtan tshigs med pa yin gyi gtan tshigs med na bsgrub bya med pa ma yin no zhes bya ba la rgyu ci zhig yod ce na / de lta na gtan tshigs mthun pa'i phyogs nyid la yod pa dang/bsgrub bya med pa la med pa nyid bstan par nus pa yin gyi bzlog pas ni ma yin no // (kim punah kāraṇam ekatra sādhyānugamo hetoh ukto dvitiye tu sādhyābhāve hetor nāstitā, na hetvabhāve sādhyasya nāstiteti / evam hi hetoh sapaksa eva sattvam sādhyābhāve cāsattvam
Dignāga on Example - 16