Seeker has to establish in the truth of Non-duality or Advaita by sheer reasoning alone

Mediocre minds waste their time on arguing about unimportant matters. Accumulation of scriptural knowledge is dangerous in pursuit of truth. Seeker has to establish in the truth of Non-duality  or Advaita by sheer reasoning alone. Seeker has to begin by defining "What is real?" "What is unreal?" etc, because that is the right way to discuss, understand and assimilate Self-Knowledge or Brahma Gnana or Atma Gnana. Thus seeker has to remove all the hindrance in order to acquire Self-Knowledge or Brahma Gnana or Atma Gnana. 

According to Advaita Vedanta, the Veda addresses itself to two kinds of audiences - the ordinary ones who desire the transitory heaven and other pleasures obtained as a result of ritual sacrifices, and the more advanced seeker who seeks to know Brahman. Thus, the purva mimam.sa, with its emphasis on the karma kanda of the Vedas, is meant for the first audience, to help lead its followers along the way. However, the Vedanta, with its emphasis on the Gnana kanda, is meant for those who wish to go beyond such transient pleasures.

An essential identity between Atman and Brahman is upheld in Advaita Vedanta. The personality of Sri, Sankara and the force of Advaita teaching is so strong that most post-Sankaran schools of Vedanta consciously define their doctrines against Advaita thought.

When Advaita declares Atman is Brahman then direct realization of truth is possible without the scriptures.  Know the soul to be the true self. And true self is in the form of consciousness and realize consciousness as ultimate truth or Brahman. 

Upanishad says:-

  This Atman cannot be attained by the study of the Vedas, or by intelligence, or by much hearing of sacred books. It is attained by him alone whom It chooses. To such a one Atman reveals Its own form. [Katha Upanishad Ch-II -23-P-20]

Mundaka Upanishad  :-

This Atman cannot be attained through study of the Vedas, nor through intelligence, nor through much learning. He who chooses Atman—by him alone is Atman attained. It is Atman that reveals to the seeker Its true nature.(3 –page-70 Mundaka Upanishad  Upanishads by Nikilanada)

When the Upanishads say:-

It is attained by him alone whom It chooses. To such a one Ataman reveals its own form.  Then what is the use of indulging through our intelligence or our accumulated knowledge, when one is not chosen by the self, which is the soul, which is in the form of consciousness.

There is no need for any philosophy in pursuit of truth because they take the seeker nearer to truth but they create more doubts and confusions.

 

The scriptures and theories and teaching based on the ego are not the yardstick. Using them as yardstick to understand and assimilate the truth will lead one towards pursuit of arguments. Seeker of truth has to discover on his own, the truth of his true existence by inquiring “what is mind?” and “what is substance of the mind?” and move forward.