While commenting on PMS 1.1.4, Veṅkaṭanātha makes a long digression aimed at refuting every kind of intellectual intuition, especially as a source for knowing dharma. Dharma, he explains, can only be known through the Veda.
People who claim to have directly perceived dharma are, by contrast, liars. This seems consistent in most cases, but may be problematic when it comes to the Veda, who are believed (by some) to have been composed by some ancient sages of the past, the ṛṣis. Veṅkaṭanātha explains that it is not the case that out of their austerities they gained the ability to directly perceive dharma, also because this would lead to a vicious circle, insofar as efficacious austerities would need to be based on the Veda. Thus, ṛṣis are not an exception to the rule.
This means that the ṛṣis did not compose the Vedas. How comes that they could teach them? Their teaching was based on the Vedas themselves (a Mīmāṃsaka would add: because time is beginningless).
Their (the ṛṣis’) teaching, by contrast, is of human origin, although it may come from the Veda (āgama). Therefore, the listeners [of such teaching] need to reflect on its root and once one eliminates that this teaching is based on a [supersensuous] perception originated out of the dharma’s energy, one needs to look for another pramāṇa for this dharma. And this is nothing but the Veda (itself) (śāstra).I am grateful to Meera Sridhara’s comment for having forced me to rethink my interpretation of śrotṛ (see below for her comment).tadupadeśasya tu āgamāyamānasyāpi pauruṣeyatayā śrotṝṇāṃ mūlaparāmarśasāpekṣatvena dharmavīryaprasūtapratyakṣamūlatvapariśeṣe tasmin dharme pramāṇāntaram anveṣaṇīyam. tac ca nānyat śāstrāt.