According to the Prābhākara Mīmāṃsā approach to language, the sentence meaning is “something to be done” (kārya). In other words, unlike for Nyāya authors, sentences do not convey the existence of something, but rather that something should be done. Sentences which look as if they were conveying a descriptive statements should be interpreted as supplementing a (at times implicit) prescriptive one. For instance “It is hot here” is a supplement of “Please, open the window” and “Vāyu is the swiftest deity” is a supplement of “One should sacrifice to Vāyu”.
Bhāṭṭa Mīmāṃsā authors do not agree with this analysis if applied to ordinary language which, they state, can also convey the description of states of affairs, but they agree that Vedic sentences only convey prescriptive contents.
This thesis has important epistemological and logical outputs. Epistemologically, it implies that the Veda is an instrument of knowledge only in relation to duties. By contrast, sense perception, inference, etc. only convey knowledge about what exists. Therefore, the knowledge of duties conveyed by Vedic sentences cannot be falsified by sense-perception, inference, etc., which convey a completely different set of contents. Therefore, since duties cannot be known through any other instrument of knowledge but the Veda, the Veda remains unfalsifiable.
From the point of view of deontic logic, the Mīmāṃsā analysis differentiates between prescriptions (vidhi) and prohibitions (niṣedha). These are distinguished on the basis of their leading or not to fruits and not on the basis of their linguistic form.
Mīmāṃsā authors developed the above theory also in opposition to Vedānta authors, who claimed that the Veda conveys descriptive contents about the brahman and the ātman.