Sage Sankara: It is possible also to show the unreality of the object world even from pure reasoning.

Sage Sankara founded his Advaita Vedanta either on reason independent of Sruti or on Sruti confirmed by reason."

Sage Sankara's commentary on the Manduka Upanishad, II, 1: This (the unreality of duality) is borne out by the Srutis ... But it is possible also to show the unreality of the object world even from pure reasoning, and this second chapter is undertaken for that purpose.

Sage Sankara himself had often said that his philosophy was based on Sruti, or revealed scripture. This may be because Sage Sankara addressed the ordinary man, who finds security in the idea of causality and thus in the idea of God—and Revelation is indispensable to prove the latter. He believed that those of superior intelligence, have no need for this idea of divine causality, and can, therefore, dispense with Sruti and arrive at the truth of Non-Dualism by pure reason.

Sage Sankara, in debates with Buddhists and others who did not recognize the authority of the Vedas, had been obliged to prove the truth of Advaita through reason alone. Manduka Upanishad, a scripture that appealed to reason to the exclusion of Revelation.

Sage Goudpada wrote his Manduka Karika to establish the truth of Non-duality by sheer reasoning alone. He begins by defining "What is real?" "What is unreal?", etc, because that is the right way to discuss or teach. People must first know what they are talking about.

Some Gurus describe perfection as the awakening to Reality—the realization that pure Consciousness alone is, that the perpetually fluctuating and evanescent contents of the mind derive from it.

This awakening effectively happens in an instant. But for the lightning flash to take place, resulting in a firm and unshakable certitude, long labor is necessary, which they seem to underestimate. “Truth is formless” is their answer.

Their teaching seems essentially negative, potent but bitter medicine for those imprisoned by institutional cults. They break the seekers’ bonds but then lead him to a vast desert where he abandons him. The ultimate state of consciousness they describe is that of the traditional sage or fully enlightened being, but they do not show us the process leading to the realization of this state. These Gurus describe marvelously the goal but do not indicate the steps to be taken: their recurring phrases "unified consciousness" and "let go" are not a road map.

These gurus' approach was more practical, and they stuck with the reality of the world, they take 'I' as real. Thus, these Gurus knew only a half-truth because that is a fallacy of the ego (form) they never realized the fallacy of time and space.

That is why Sage Sankara says in the commentary in Vedanta-sutra that what is accepted without a proper inquiry will not lead a person to the final goal. On the contrary, such acceptance will result only in evil, something which is detrimental to our spiritual progress.

Seekers of truth should not believe blindly in traditional orthodox nonduality without verifying all the facts from every angle. One has to reflect through reasoning over and over again without getting tired of the process. :~Santthosh Kumaar