Hence, other instruments of knowledge just do not become active in regard tosomething which has already been known (see Katoka, JIPh 2003). So, Mīmāṃsakas separate the realm of what can be known in two ﬁelds:
sensory items ––» known through sense perception
transcendent items ––» known through verbal communication (Veda)
The Veda, as explained by Śabara, corresponds to sense perception in conveying a direct knowledge of transcendent items.
This is an implicit criticism against these schools (e.g. Śaivasiddhānta or, later on, Gauḍīya Vaiṣṇavism) who allegedly acknowledge the authority the Veda, but de facto abolish it, insofar as they propose other Sacred Texts/practices/rituals as more effective for the attainment of the summum bonum.
In modern terms, it is interesting to note that the Veda seems to be considered only as an instrument of knowledge. No one proposes that the Veda might have a purpose beside being informative. Does this mean that no connotative purpose is taken into account? Not really, since the indirect signification would also be a plausible content to be conveyed by an instrument of knowledge.