But even if you don’t agree, let me point to the distinction between

• the use of such arguments as a way to close a discussion (e.g., “It is the case that X, because an authoritative source said it”)
• the use of such arguments as part of a discussion or as opening a discussion (e.g., “An authoritative source tells us that X, how shall we understand it?”)

Mīmāṃsā authors use the second approach. Interestingly, even a Viśiṣṭādvaitin like Veṅkaṭanātha follows the same approach. Let me mention an extreme case, that of the validity of the Pañcarātra Sacred Texts, for which Veṅkaṭanātha may be in need to grab at straws. After all, the Pañcarātra Saṃhitās are not the Vedas, nor do they appear to be directly based on the Vedas. Veṅkaṭanātha shortly mentions the argument that they are valid because they have been authored by God, but then goes looking for arguments which can be shared even by his opponents.

Is the first approach ever used? Could this distinction be used as a way to distiguish people engaging in a public discourse and people writing for other purposes (e.g., energising only a given group of people)?
Again, Veṅkaṭanātha chose to use arguments which where based on the same presuppositions as his opponents’ ones instead of saying that the Pañcarātra Saṃhitās were valid because God authored them*.

*Please notice in this connection that God can be part of a philosophical argument, e.g., in rational theology. The point here is just that Veṅkaṭanātha did not close the discussion by mentioning God.

For another way to approach the topic of distinguishing various types of texts, see this post by Jonathan Edelmann.