Sat-darshana Bhashya (translation)

Verse 12.

विद्या कथं भाति न चेदविद्या
विद्यां विना कि प्रविभात्यविद्या।
द्वयं च कस्येति विचार्य मूल-
स्वरूपनिष्ठा परमार्थविद्या॥

If ignorance were not, how can knowledge be?
If knowledge were not, how can ignorance be?
Searching close the source of both,
Settled state there is knowledge true.

The dual terms of knowledge and ignorance are relative and one should discover their root in something, which is neither of them, by a kind of psychological examination of self. For instance, when I say ’I am aware,’ or ’I am ignorant, the quest that is suggested here is to find out who it is that knows or who it is that knows not. The quest, when serious, involves a close watchfulness bearing fruit in the discerning of a supreme awareness in the self, which is the source of all forms of consciousness. And this is real knowledge, for it is not a mental conception, or intellectual conviction but a revelation, a realisation, an experience, a consciousness that is supreme knowledge paramartha vidya.

Thus after speaking of the search for the source of the duality of knowledge and ignorance, the Shastra proceeds to explain the subtler method of getting at the ultimate truth by direct experience and knowledge by identity, by meditating upon and comprehending the truth underlying the knower, knowledge and known.