Shabda. ("word") is a broad word for authoritative testimony in Indian philosophy.
Save for materialists, who deny all pramanas except
perception, this is widely acknowledged as one of the pramanas, the way by
which human beings may receive real and accurate knowledge (pratyaksha).
There are two types of authoritative witness.
It most commonly refers to authoritative scripture sources,
such as the Vedas, but it may also refer to vocal instruction delivered by
one's guru, which is seen as having equal authority, at least by those who
belong to that spiritual lineage.
Shabda is a significant pramana because it reveals
information that the other pramanas are unable to provide, such as the nature
of the heavens, the path of the soul after death, appropriate religious life, and
so on.
It is often the most essential pramana in terms of soul
liberation, since it cannot be discovered any other way.
