There is nothing more rational, more intelligible and more un-dogmatic insights of Sri, Sankara, is to drop all the theistic non-duality or Advaita which is meant for those who are incapable and not receptive to realize the ultimate truth or Brahman.

There is no need to practice to Devotion, Karma and Raja yoga because they are not the means to acquire non-dual wisdom.   There is no practice as such but perfect understanding is needed.   Deeper self-search   reveals the fact that, the self is not physical but the self is formless soul, which is present in the form of  consciousness. Therefore, all the accumulated knowledge, experiences and understanding based on physical self (ego or waking entity) are falsehood based on the false self, within the false experience (waking).   Thus, whatever is based on the waking entity is bound to be falsehood because waking experience itself is false hood.   Since many teachers and teachings are based on the false self (ego or waking entity)] and they consider the false experience (three states) as reality, they are incapable of grasping the witness, which is within the three states, but it is without the three states.

 Thus,  the seeker has to become aware of the existence of  a formless witness of the three states . The seeker has to  realize the fact that, all the three states, which comes and goes, are mental.  They are impermanent. The formless witness or knower of the three states is permanent and eternal.  Therefore, there is a need to understand “What is Mind?” and “What is the substance of the Mind?” in order to understand and assimilate the non-dual truth.

 For this one has to drop all his accumulate knowledge. The seeker should not use the any teaching or any teacher as  as  a  yardstick  because there is no need for any teacher and teaching to realize the truth , which is beyond form, time and space. There is no need to argue holding some guru's words as final authority without verification. Only verified truth has to be accepted as truth.    

There is no need to argue in pursuit of truth because the truth has to be ascertained by the seeker himself. The argument leads nowhere. Perfect understanding of 'what is what' is very much necessary.  One has to think deeper and analyze and verify everything and accept only un-contradictable truth.  Nothing has to be accepted as truth because some great thinker says it or some Guru  saying it.  

Those who lack the intelligence to discriminate between formless witness (soul or subject) and three states (object) will not be able to grasp what is real and what is unreal. Both subject and object are consciousness, not subject alone.

The truth can never change. The nature of truth is, it can never be changed under any circumstances. It may be misrepresented. It must apply to the whole of existence, to the whole of the universe. It is in the object (three states) alone that one has all changes, as deeper analysis points out.

 The subject (formless witness) remains unchanged. The subject (soul or formless witness), as such remains immortal. It can never die for it never changes. The body and the world are an object, and goes, but the subject or the knower of the body and the universe, can never go.

The Seeker has to take this principle as his guiding thread and non-dual truth becomes easy to grasp. The formless witness can never be subject to the changes of the object; it is unchanged. The mistake usually made is that subject becomes object, or that object is subject.

If one wants to have an absence of contradictions, absence of duality, there must be one entity, one being. If one has experience which is an object (mind), there is a contradiction between subject and object, for "mind” is an object.

The duality is reality on the standpoint of the false self (ego or body as the Self).  The duality is a mere mirage on the base of the true self, which is formless consciousness. This understanding comes only to the serious seeker, who has a real urge to know the ultimate truth, which is beyond the all the teachings and teachers. There is neither teaching, nor teacher, nor student in the realm of truth.   

Appearances and quotations have nothing to do in pursuit of truth. There is no need to condemn yoga, as it helps only to regulate the minds of novice. The difference between self- knowledge and meditation is that self- knowledge will be determined by the nature of the object to be known, whereas meditation will be determined by the nature of the meditator.

People have the same belief about their respective God or Guru and Religion. One whose doubts vanish merely by sitting in the presence of a mystic or Yogi, have merely been hypnotized. From psychology the seeker  to work deeper to epistemology. 

Quoting scriptures or any authority is not the proof of the truth. The scriptures are not proof of the truth.  The truth has to be proved without the scriptures. People take to the path of belief or of authoritarianism merely because they are the easiest ways. To seek for proof is troublesome and time taking. Religion and mysticism are very much preferred to self-knowledge, because one has only to imagine, not to inquire and reason. The first is easy the second is hard.  

There is need to study the scriptures. One has to self-search the truth and realize it without the scriptures. And then when he reads the scriptures he becomes aware the scriptures are also saying the same thing but everything is misinterpreted.    

That is why Sage  Sri, Sankara says in : - VC 58. Loud speech consisting of a shower of words, the skill in expounding the Scriptures, and likewise erudition - these merely bring on a little personal enjoyment to the scholar, but are no good for Liberation. 

59. The study of the Scriptures is useless so long as the highest Truth is unknown, and it is equally useless when the highest Truth has already been known.

60. The Scriptures consisting of many words are a dense forest which merely causes the mind to ramble. Hence men of wisdom should earnestly set about knowing the true nature of the Self.

61. For one who has been bitten by the serpent of Ignorance, the only remedy is the knowledge of Brahman. Of what avail are the Vedas and (other) Scriptures, Mantras (sacred formulae) and medicines to such a one?

62. A disease does not leave off if one simply utters the name of the medicine, without taking it; (similarly) without direct realization one cannot be liberated by the mere utterance of the word Brahman. 

There is nothing more rational, more intelligible and more un-dogmatic insights of Sri, Sankara, is to drop all the theistic or orthodox  non-duality or Advaita which is meant for those who are incapable and not receptive to realize the ultimate truth or Brahman. 

If one merely theorizes, tries to understand through his intellect and there contended he cannot become a Gnani but he becomes a scholar or a pundit.   Seeker of truth must make what he has understood and assimilated has to be  realized, to get a firm conviction of the non- dualistic truth or ultimate truth or Brahman,   then only it is possible for him to transcend all the limitations of the experience of form, time and space.    

The existence beyond limitations of form, time and space is known as Moksha or Nirvana. Spiritual freedom or self-realization is the goal of every seeker of truth.