Some of the sources of Pramana in Vedantic philosophy are Shabda (scriptures), Pratyaksha (direct perception) and Anumana (inference).
In Vedantic philosophy, Shabda occupies the highest source of truth. Are there any rules regarding interpretation of Shabda with respect to Pratyaksha? Can they contradict each other? In today's world what constitutes Pratyaksha? Does new knowledge obtained from Pratyaksha have any effect on the interpretation of Shabda?
Nice Question. This post is to attempt to answer 2 of your questions in context to Vedanta (you may infer the rest from the below answer too) -
Are there any rules regarding interpretation of Shabda with respect to Pratyaksha? Can they contradict each other?
The same question is posed by Yudhistira to Bhishma (in a different form). This can be found in Chapter 162, Anushasana Parva, Mahabharata. I have pasted the relevant sections below (providing only relevant text) but i urge you to read the entire chapter for contextual understanding.
"Yudhishthira once more asked Bhishma the son of Santanu, saying, 'O thou of great intelligence; O foremost of all persons conversant with duties, which, indeed, of the two, direct perception and the scriptures, is to be regarded as authority for arriving at a conclusion?'
"Bhishma said, 'I think, there is no doubt in this. Listen to me, O thou of great wisdom! I shall answer thee. The question thou hast asked is certainly proper. It is easy to cherish doubt. But the solution of that doubt is difficult.
Innumerable are the instances, in respect of both direct perception and audition (or the scriptures), in which doubts may arise. Certain persons, who delight in the name of logicians, verily imagining themselves to be possessed of superior wisdom, affirm that direct perception is the only authority. They assert that nothing, however true, is existent which is not directly perceivable; or, at least they doubt the existence of those objects. Indeed, such assertions involve an absurdity and they who make them are of foolish understanding, whatever may be their pride of learning. If, on the other hand, thou doubtest as to how the one (indivisible Brahman) could be the cause, I answer that one would understand it only after a long course of years and with the assistance of Yoga practised without idleness. Indeed, O Bharata, one that lives according to such means as present themselves (without, i.e., one's being wedded to this or that settled mode of life), and one that is devoted (to the solution of the question), would be capable of understanding it. None else, truly, is competent for comprehending it. When one attains to the very end of reasons (or reasoning processes), one then attains to that excellent and all comprehending knowledge--that vast mass of effulgence which illumines all the universe (called Brahma). That knowledge, O king, which is derived from reason (or inferences) can scarcely be said to be knowledge. Such knowledge should be rejected. It should be noted that it is not defined or comprehended by the word. It should, therefore, be rejected!'"
"Yudhisthira said, 'Tell me, O grandsire, which among these (four) is most authoritative, viz., direct perception, inference from observation, the science of Agama or scriptures, and diverse kinds of practices that distinguish the good.'
"Bhishma said, 'While Righteousness is sought to be destroyed by wicked persons possessed of great might, it is capable of being protected for the time being by those that are good exerting themselves with care and earnestness. Such protection, however, avails not in the long run, for destruction does overtake Righteousness at the end. Then, again, Righteousness often proves a mask for covering Unrighteousness, like grass and straw covering the mouth of a deep pit and concealing it from the view. Hear, again, O Yudhisthira! In consequence of this, the practices of the good are interfered with and destroyed by the wicked. Those persons who are of evil conduct, who discard the Srutis--indeed, those wicked wights who are haters of Righteousness,--destroy that good course of conduct (which could otherwise be set up as a standard). Hence, doubts attach to direct perception, inference, and good conduct.
Those, therefore, among the good that are possessed of understanding born of (or cleansed by) the scriptures and that are ever contented, are to be regarded as the foremost. Let those that are anxious and deprived of tranquillity of soul, approach these. Indeed, O Yudhishthira., do thou pay court to them and seek of them the solutions of thy doubt! Disregarding both pleasure and wealth which always follow lust (desire) and awakened into the belief that only Righteousness should be sought, do thou, O Yudhishthira, wait upon and ask those persons (for enlightening thyself). The conduct of those persons never goes wrong or meets with destruction, as also their sacrifices and Vedic study and rites. Indeed, these three, viz., conduct as consisting of overt acts, behaviour in respect of (mental) purity, and the Vedas together constitute Righteousness.'
