Sage Sankara' gave religious, ritual, or dogmatic instruction to the masses, but Advaitic wisdom only to the few who could rise to it.+

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 Sri, 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' gave religious, ritual, or dogmatic instruction to the masses, but Advaitic wisdom only to the few who could rise to it. Hence, the interpretation of his writings by commentators is often confusing because they mix up the two viewpoints. Thus they may assert that ritual is a means of realizing Brahman, which is absurd.

Adhyasa Bhashya of Sage  Sankara:~ (11) As regards the rituals, Sage  Sankara says, that the person who performs rituals and aspires for rewards will view himself in terms of the caste into which he is born, his age, the stage of his life, his standing in society, etc. In addition, he is required to perform rituals all through his life. However, the Self has none of those attributes or tags. Hence, the person who superimposes all those attributes on the changeless, eternal Self and identifies the Self with the body is confusing one for the other; and is, therefore, an ignorant person. The scriptures dealing with rituals, rewards, etc. are, therefore, addressed to an ignorant person.

Adhyasa Bhashya of Sage Sankara:~ (11.1) This ignorance (mistaking the body for Self) brings in its wake a desire for the well-being of the body, aversion for its disease or discomfort, fear of its destruction, and thus a host of miseries(anartha). This anartha is caused by projecting karthvya(“doer” sense) and bhokthavya (object) on the Atman. Sage Sankara calls this adhyasa. The scriptures dealing with rituals, rewards, etc. are, therefore, he says, addressed to an ignorant person.

Adhyasa Bhashya of Sage Sankara:~ (11.2) In short, the person who engages in rituals with the notion “I am an agent, doer, thinker”, according to Sage Sankara, is ignorant, as his behavior implies a distinct, separate doer/agent/knower; and an object that is to be done/achieved/known. That duality is avidya, an error that can be removed by vidya.

Adhyasa Bhashya of Sage Sankara: ~ (12) Sage Sankara affirming his belief in one eternal unchanging reality (Brahman) and the illusion of plurality, drives home the point that Upanishads deal not with rituals but with the knowledge of the Absolute (Brahma vidya) and the Upanishads give us an insight into the essential nature of the Self which is identical with the Absolute, the Brahman.

Sage Sankara: ~ Atman, the Self is verily Brahman (God in truth), being equanimous, quiescent, and by nature absolute Existence, Knowledge, and Bliss. Atman is not the body that is non-existence itself. This is called true Knowledge by the wise. :~ Santthosh Kumaar