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TEST OF TRUTH AND ERROR
105 to be invalid. Here the invalidity of the first is known through something other than itself. That the third is consistent with the second does not mean that it validates the second. It means only that the doubt attaching to the second is dispelled by its coherence with the third. Hence it follows that every knowledge validates itself through itself and is invalidated by some other knowledge. That is, validity is intrinsic to all knowledge, while invalidity is extrinsic and accidental.'
The Naiyāyıkas reject the first part of the Mīmāmgā theory, namely, that knowledge is both made valid and known to be valid by its own intrinsic conditions. The validity of knowledge cannot be due to the conditions of knowledge as such. If that were so, there could not be any invalid knowledge, since even invalid knowledge arises from the conditions of knowledge. In fact a valid cognition is more than a cognition as such. Hence it must be due to some special character of the general conditions of knowledge just as an invalid cognition is due to some positive factors that vitiate the general conditions of knowledge. The mere absence of vitiating factors cannot account for the positive character of validity. Thus the validity of perception is due not merely to the absence of vitiating factors like the diseased condition of the sense-organ, but to such positive factors as the healthy condition of the sense-organ, etc. Similarly, in all other cases the validity of knowledge is due to some special auxiliary conditions in the specific causes of knowledge (kāranaguna). Such special conditions may not be always perceived, but they may be known from other sources, like inference and testimony. The special efficacy of the sense-organs may be known from the medical sciences. Further, if the validity of knowledge be due simply to the absence of vitiating conditions, its invalidity
1 NM., pp. 166-67.
14—(1117 B)
