Nyaya's Logical Model for Ascertaining Sound Arguments - Logic and Its Applications - page 172

criteria of soundness. Arguments which satisfied all the required criteria were determined
to be sound. Arguments which failed to satisfy the criteria were rejected, however con-
vincing they may have seemed.

2 The Four Criterions of Knowledge, the Four Pramān  as

2.1 The Pratyaks  a-pramān  a, the Criterion of Perceptual Knowledge

Uddyotakara, the author of the Nyāyavārtika, the second commentary of the Nyāyasūtra,
which was composed probably during the 6 th century AD, presents the outlines of his
theory of pramān  a already in the introduction of his work. The discussion in the intro-
duction is divided to three parts, each one of which is dedicated to the clarification of a
key concept Vātsyāyana uses in the opening sentence of the Nyāya-bhāsya. The opening
sentence of the Bhāsya states that " pramān  a is useful and it is fully compatible with its
objects ( arthavat) because the capability to act ( pravr  r  t  i-sāmarthya) reveals that the ob-
ject of perception was obtained by pramān  a ". Uddyotakara first turns to examine the
relation between pramān  a and samartha-pravr  r  t  i - meaningful, compatible and compe-
tent activity. It seems Uddyotakara considers the clarification of the relation between
pramān  a and samartha-pravi , which he takes to be a relation of mutual-interdependence,
to be crucial to the understanding of Vātsyāyana's statement ' pramān  a is arthavat '.
Uddyotakara does not consider the relation between pramān  a and samartha -
pravr  r  t  i to be a causal relation. He makes this point perfectly clear in his response to the
following objection: The pūrvapaks  in notes that whereas it is perfectly reasonable to
maintain that pramān  a conditions samartha - pravr  r  t  i , it is senseless to maintain that sa-
martha - pravr  r  t  i conditions pramān  a , since the latter temporally precedes the former. 3 In
causal relations, time plays a crucial role. If relata x conditions relata y it follow that rela-
ta x temporally precedes relata y ; and if relata y is temporally posterior to relata x , it fol-
lows that it is impossible for relata y to condition relata x . Under such circumstances, it is
indeed impossible for samartha - pravr  r  t  i to condition pramān  a . Uddyotakara responds by
saying that time plays no role in the analysis he presented of the relation between
pramān  a and samartha - pravr  r  t  i . 4 If the relation between pramān  a and samartha - pravr  r  t  i
is a kind of relation in which time plays no role, it cannot be a causal relation, and if it is
not a causal relation, there is no reason to withdraw the claim that pramān  a and samar-
tha - pravr  r  t  i are mutually interdependent. If Uddyotakara holds time to have no bearing
on the relation between pramān  a and samartha - pravr  r  t  i , he must be holding pramān  a
3 NV 1.1.1, pp. 3 line 4 - परपरापेिवादुभयािसिरित चेत् - न, अनादवात्. यद
माणतोSथितपौ वृिसामयम्, यद वा वृिसामयात् माणतोSथितपिः, क पूव क वा
पादित वायम्. यद तावत् माणतः पूवमथितपिः, वृिसामयमतरेण किमित ितपते? अथ
पूव वृिसामयमनवधायाथ किमित वतते? तमात् वृेः माणतोSथितपेरवा पूवापरभावो न
कयते इित.
4 NV 1.1.1, pp. 3 line 9 - त नैवम्. कमात्? अनादवात्. अनादरयं संसार इित पूवायतसूे
ितपादिययामः. आदमित च संसारे एष दोषः, क पूव माणतोSथितपिः, आहोिवत् पूव
वृिसामयिमित.