I guess that my purpose in showing tidbits of the Indian discussion about the perceivable nature of dharma could get lost until I spell it out: What is a direct perception which perceives imperceptible things? A Mīmāṃsā author would stick at his empiricism and say that it is no direct perception (and that it does not exist). But the definition of direct perception is just human-made, hence. conventional. It is based on average human beings and although such average human beings are the absolute majority of the human adult population, this is still no definitive argument for ruling out exceptions as "mistakes". Still, what is left to us –the majority of the population– unless we can rely on such average data? What if perception could be totally different from the sense perception we are used to? This does not amount to a philosophical experiment like the "brain in the vat" one, because it should refer, in the intention of Dharmakīrti-like Buddhists, at least, to an actual (even desirable) possibility, the attainment of awakening. Furthermore, such possibility is said to be humanly reachable. So, there are human beings who developed a faculty (perception of imperceptible things) which is altogether absent in normal human beings, but CAN be reached by them.
How can such a faculty develop out of nothing? Should not it be present to a lesser degree in all of us? Buddhist and Nyāya authors seem to deny it altogether (if it were so, then everyone would be justified in using its own faculties to build its own set of beliefs, relying on the scant "amount" of dharma he can see by herself). But it is surely not impossible as a logical contradiction is.