 In this connection, we may note that Mīmāṃsā and other systems of Hindu philosophy developed a notion of linguistic expression as one of the sources of authoritative knowledge (śabdapramāṇa), when other more basic sources of knowledge like sense perception (pratyakṣa) and inference (anumāna) are not available. Particularly, in connection with religious duty (dharma), and heaven (svarga) as the promised reward, only the Veda is available as the source of authoritative knowledge. For Mīmāṃsā, the Veda as a source of knowledge is not tainted by negative qualities like ignorance and malice that could affect a normal human speaker.