Another argument for God’s existence is based on the authoritative character of the Vedas. The authority of the scriptures is accepted as unquestionable and infallible in all religions.
Now the question, we are to consider here, is this: What is the source of the authority of the Vedas? According to the Naiyayikas, the authority (pramanya) of the Vedas has its source in the supreme authority of their author (aptapramanya).
Just as the authoritativeness of the medical science, or for that matter, of all sciences, is derived from the scientists who founded them, so the authoritativeness of the Vedas is derived from some person who imparted that character to them.
The validity of the Vedas maybe tested like that of any science, by following their injuncdons about worldly objects and seeing how they produce the desired result.
Of course, the truth of other Vedic texts bearing on supersensible objects cannot, like some scientific truths, be tested in this way.
Still, we may accept the whole of the Vedas as valid and authoritative, in the same way in which we accept the whole of science as true when, as a matter of fact, we can verify only some parts of it.
So we must explain the authority of the Vedas by referring them to some authoritative person.
Now the individual self (jiva) cannot be the anthor of the Vedas since the supramundane realities and the transcendent principles related in the Vedas cannot be objects of the knowledge of any ordinary individual.
Hence the author of the Vedas must be the suprme person who has a direct knowledge of all objects, past, present and future, finite, infinite and infinitesimal, sensible and supersensible. That is, the Vedas, like other scriptures, are revealed by God.