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MASAAKI HATTORI
of the Vaiseșika theory, there is no trace to show that aprasiddha was taken to imply asiddha or viruddha. The asiddha fallacy is not acknowledged to have been known to the Vaišeşikas or to the Naiyāyikas before a systematic classification of fallacious reasons based on the theory of linga-trairūpya was made by Prasastapāda. The explanation given by Vyomasiva and Sridhara for identifying aprasiddha with viruddha is obviously foroed. That which is a prasiddha in similar instances is not always a viruddha. What constitutes the characteristic feature of viruddha is that it proves the opposite of what is to be proved.
Thus it seems quite likely that Dignāga's criticism impelled Prasastapāda to abandon the older Vaiseșika theory of the fallacious reason. Instead of introducing modifications to the older theory, Prasastapāda found it more convenient to adopt wholly Dignāga's classification of fallacious reasons based on the theory of lingatrairūpya. Apparently aprasiddha was no longer recognized by him as a type of fallacious reason. He cited the sūtra with a pretence of following the tradition, but his commentators were compelled to a forced interpretation of the older terminology.
The other two fallacious reasons, asat and samdigdha, are illustrated in VS, 3.1.12: vişāni tasmäd aśvo visāni tasmād gauḥ (It is a horse, because it has horns; It is a cow because it has horns). Dignāga says first that the reason itself, i. e., hornedness (vişānitva) in both illustrations, is neither absent (asat) nor doubtful (samdigdha): it is a well-known property of the subject of the proposition. This is no more than a quibble: it is clear that asat and samdigdha in the sūtra are meant for expressing the reasons which prove respectively that which is absent and that which is doubtful. But, Dignāga continues, that which is absent (asat) is not proved by this type of reason: what is proved by the reason ‘hornedness' is not the absence of a horse, but it is that which is contrary. (viparita) to a horse. "Therefore, this reason) is called a contradictory reason (viruddha) as it proves the opposite (of what is to be proved] (viparitasādhanāt) 33.”
Both Vyomasiva and Sridhara identify asat with asiddha for the reason that asiddha is absent in the subject of the proposition 34. But, as stated above, the asiddha fallacy was not known to the older Vaiseșikas. Evidently asat in the Vaišeşikasūtra corresponds, as Dignāga
33 PS, K 147 a.7-147b.2 (V 63a.3-6): ... deci phyir edi ni Ogal ba yin te bzlog pa sgrub par byed paci phyir ro.
34 Nyāyakandali, p. 205.4: ... dharmiņi vrttyabhāvät... Vyomavati, p. 569.26-27: asann ity asiddhah, tasya hi pakşadharmatvenāsattvät. Cf. Candrānanda on VS, 3.1.11.
