Upanishads say:- It is attained by him alone whom It chooses.

The 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 the study of the Vedas, nor through intelligence, nor through much learning. He who chooses Atman—by him alone is Atman attained. It is the 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 Atman 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 the 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 the 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 the substance of the mind?” and move forward.  

The ultimate truth is one without the second, the one is not in the sense half or two, but the one that remains forever One, without the second.  The consciousness is all pervading. There is no place where consciousness is not.

Consciousness is in everyone, consciousness is in everything,  consciousness is one behind many. Consciousness alone is. It means the universe and its contents are the visible form of consciousness. And consciousness in turn is invisible form of the universe, which appears as mind.