________________
[proposition] Qa
[reason] Pa [similar ex.] (x)(Px [dissimilar ex.] (x)(-Qx
Qx) & (Ex) (Px & Qx) & (x
a) -Px) & (Ex)(-1x & -Qx) & (xa)
Based on his conviction that a valid proof should be formulated in the way discussed above, Dignaga criticizes what he regards as the wrong formulations of a proof given by rival schools. For example, he picks up the following anonymous proof:22
[proposition] "nityaḥ śabdah" (Sound is eternal.)
[reason]
"sarvasya anityatvät" (Because everything is non-eternal.) [Proof 3]
On the first sight, the proposition and the reason of Proof 5 appear to be incompatible with each other (viruddha). However, if you take into an account that the topic of a proposition is not included in our Induction Domain in the traditional Indian logic, Proof 5 makes sense by interpreting its reason in the sense that everything except for sound (i.e., the topic of the proposition) is non-eternal. In this connection, Dignaga points out that the reason of Proof 5 does not really express the reason but actually expresses the dissimilar example. Then he proposes the following formulation:
[proposition] "nityaḥ sabdaḥ" (Sound is eternal.)
[reason]
(sabdasya) asarvatvāt " (Because sound is not everything.) [dissimilar ex.] "sarvam anityam yatha ghaṭaḥ" (Everything is non-eternal as e.g. a pot.) [Proof 4]
Having criticized the above reason from various points of view, Dingāga
22 NMukh §1.4, Katsura (197x: xx). and PS III. 6: hetupratijñāvyāghāte pratijñādoṣa ity asat/sa hi dṛṣṭānta evôkto vaidharmyeṇāsušikṣitaiḥ // Quoted in PVA: 563; and PSV ad PS III.6.
Dignaga on Example - 13