284 Journal of the Asiatic Society of Bengal. [N.S., XIV, 
is valid knowlege inasmuch as silverness which is a generic 
nature, really abides in the individual silver which is its subject. 
wo questions arise here: (1) whence is the validity of 
How is valid knowledge 
derived and known ? 
Gangesa opposes the first reply by saying that if the valid- 
ity of knowledge were derived from the general grounds of 
knowledge itself, then invalid knowledge would have been iden- 
tical with valid knowledge. The second reply is also opposed 
on the ground that if we were conscious of the validity of 
knowledge along with our consciousness of knowledge itself, 
there could not have arisen in us doubt with regard to the valid- 
ity of any kind of knowledge specially in the unhabitual 
condition. But there often arises in us knowledge of a dubious 
consciousness of knowledge there is, according to them, along 
with it a consciousness of its validity which leaves no room y 
doubt; and if, on the other hand, there is no consciousness 0 
is not derived from its general grounds (or causes). It is acco i 
ing to him derived through its special cause called instrument. 
ity of a particular knowledge does not arise from our oon 
ness of the particular knowledge itself, but from a din 
Source, viz. inference from the fruitful correspondence Lap 
our knowledge (idea) and the activity prompted by It. to 
knowledge (idea),” says he, “is valid because it is conducly? 
activity which is fruitful ; whatever is not conducive to actl¥! : 
which is fruitful, is not valid knowledge.’ Suppose, for instane 
# Person cognises from distance a white thing to be a ae a 
silver. His knowledge will be valid if it harmonises wit 
