In Hindu philosophy, Anupalabdhi is non-perception as a means of knowledge. It is one of the six independent means of valid knowledge. Apart from anupalabdhi, according to Advaita and Bhatta Mimamsa, the other five means of valid knowledge are perception, inference, comparison, verbal testimony and implication. Like perception, non-perception, too, relates to the present and has a direct perceptual character. It is an independent means of knowledge because it leads to cognition which no other positive means of knowledge could provide.
Non-perception works only in regard to the non-existence of
that whose existence could have been known by other positive means like
perception had it existed in the first place. For instance, a pot not visible in
darkness can much less be known by this means of non-perception. Non-perception
as such cannot be a proof of non-existence. Factors like too much proximity,
too much remoteness, disturbance of the sense-organs, inattention, obscurity of
the object, extreme subtlety or confusion with other objects may cause non-perception.
Prabhakara Mimamsakas and the Samkhyas urge that there is no
such category as non-existence. The non-existence of a pot on the ground is
only the ground and nothing more. If this contention were true, it will follow
that even when there is existence of the pot on the ground, its non-existence
has to be known, since even then there is perception of the ground. Again, mere
bare ground cannot be a proof of the non-existence of the pot because many
other things do not exist on the ground. The Naiyayikas contend that
non-existence can never come into sense-contact in any kind of relation, either
like a substance or its attribute.
When it is said by the Advaitins that non-perception has a perceptual
character, it does not mean that it is perception but only that the instrument
of that knowledge is non-perception, a distinct means of knowledge. It is not
necessary that pratyakshatva (a perceptual character) should invariably be
brought about by sense-contact. It can be the result of verbal testimony too.
For example, in the statement ‘Thou art the tenth’, directly addressed to
remind a person in a group of ten who has forgotten to count himself as the
tenth and who mourns that the tenth person in the group is missing. There is an immediate perceptual knowledge of the
person who realizes that he is the tenth. But the statement ‘Thou art the tenth’
is not perception but verbal testimony.
Naiyayikas, who admit non-existence as a category, offer the
theory that the non-existence of the pot, for instance, on the ground, is known
by direct perception as qualifying the ground. This vivesanata (a kind of
sense-contact) is conceived by them to know the fact of non-existence. Hence they
do not admit anupalabdhi as an independent pramana.