Buddha said :- Do not believe a spiritual teaching just because:-

In ancient times people were simply curious sought some knowledge of the sun and stars; but in modern mind set have brains, they are ready to inquire and reason, and acquire knowledge of the self.” they begin with a doubt and finally clear all the doubt and realize the reality.


In the confusing multiplicity of doctrines, each has his own theory, he does not have time to think and inquire if it be true. Yet doubt is the fist step to knowledge for the thoughtful. On the other hand, seeker of truth must never be satisfied with mere skepticism, have the hope that one’s doubt will be solved, and go forward. Reason tells one what is good and what is bad, what should be followed and what let alone. 

 
Seeker should pursue this quest until all his questions will be answered, until his doubts and confusions will disappear and solved.

• How does he know that scriptures are true?

The sages, seer or prophets might have been mistaken. To accept these scriptures without verification and proper  reasoning is to possess the slave mentality.

That is why Buddha said :- 

No one saves us but ourselves.

No one can and no one may.

We ourselves must walk the path.

-Buddha

Buddha said :-

Do not believe a spiritual teaching just because:-

1. it is repeatedly recited,
2. it is written in a scripture,
3. it was handed from guru to disciple,
4. everyone around you believes it,
5. it has supernatural qualities,
6. it fits my beliefs anyway,
7. it sounds rational to me,
8. it is taught by a respectable person,
9. it was said to be the truth by the teacher,
10. one must defend it or fight for it.


That is why Sri, Sankara indicates in (VC):-

56. Neither by Yoga, nor by Sankhya, nor by work, nor by learning, but by the realisation of one's identity with Brahman is Liberation possible, and by no other means. 

 
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.

Self-Realization is direct realization of the ultimate truth or Brahman, in contrast with traditional paths, which are indirect. And the other paths cannot lead to the ultimate destination because they are based on the false self(ego or waking entity), which they hold as real self and false experience(waking) as reality.

Only when  one is able to  overcomes physical shackle (mind or waking or universe)than only it is possible to understand and assimilate the non-dual truth, which is beyond the experience of form, time and space. Soul or Consciousness itself is lord of itself though not of the universe. And having nothing it has all.

Inborn and inherited samskara and conditioning is the root of the ignorance.

Path of wisdom is not for those who have the firm conviction about religion, yoga and theories as the only means to highest truth and what he knows or believes is ultimate truth.

 

In practical life, religion and yoga are needed.  Religion is the tool to give samskara or conditioning   to the mass, -- to be, to believe, to behave and to live in cultured society with its code of conduct with the fear of god, but are of no value as proof.  Wisdom is  for getting  rid of  the inborn and inherited   samskara or conditioning.  Inborn and inherited samskara and conditioning  is the root of the ignorance. 

Intellectuals think that Ultimate truth cannot be known. They do not want o discuss nor accept anything whatever they know and accepted as truth.  "What I know is right, what another man knows is wrong." This unfortunate vanity is common to all men and prevents realization. A man must begin by doubting his own knowledge, therefore. Only when doubts begin to arise does a man start in quest of Truth. And such doubts usually first take the shape of asking why God sends or permits epidemics, calamities and wars and unrest.  

Quotation from others should come only after verification   convinced by use of reason based on facts, and then only may one introduce quotations in order to show that others have reached the same conclusion. 

One must go to the very fundamentals, to the root of thinking, to "grasp the ultimate truth, which is beyond form, time and space. 

How does one know what others say and quote is true?  When this question arises from within than the inner dialogue starts within and the truth will start revealing on its own. 

When all the doubts are cleared within, that is the doubts on every question. However, ultimate understanding cannot be reached without having doubts and asking questions and demanding proofs from one’s own innermost self. 

To overcome doubt by the sword of wisdom, it does not mean that seeker should give up his doubt and believe, as the religionists and intellectuals interpret it, but that he should keep on thinking about his doubts until they are solved; that he should not stop until this point is reached.

In pursuit of truth the ultimate truth has to be proved, not assumed.

In pursuit of truth the ultimate truth has to be proved, not assumed. Pundits who take scriptures for granted are not Gnanis. 

Pundits teach that all is your-self, but none of them can show that this is so, none has analysed it scientifically, and none can prove it. Rational proof is needed, so that one arrive at knowing truth i.e. wisdom; punditry is mere dogma, parrotism, repetition of what they read in scripture. Scriptures are not yardstick and scriptural truth is not proof.   Pundits take scriptures as authority.   Authoritarianism merely assumes as true what another says, but what has yet to be proved. 

Pundits have to test truth in this world not in the next world.  There is no proof other than blind belief based on the scriptures, belief is not truth.  So, doctrines are not the means to realize the ultimate truth. There is no need to follow them. 

Doubts and Confusions arise when seeker finds the scriptures and yoga are inadequate or useless to quench his spiritual thirst.   Disappointments in religion or yoga or even science imply error or ignorance. 

When serious seeker reaches a stage with all his baggage of accumulate knowledge, then uncertainty haunts him.  Whether he is right?" Where is the certainty that he is proceeding on right lines?" Thus doubts arise and the inquiring spirit comes and impels to search elsewhere for truth where it will not be possible even to have doubt. The test is therefore in experience. And only in non-duality, where there are no two to argue about views or to have difference of opinion can such doubtlessness be possible.  Belief depends upon unstable bases whereas certainty depends on proof. 

Sri, Sankara says in Viveka Chudamani indicated that:-

 

56. Neither by Yoga, nor by Sankhya, nor by work, nor by learning, but by the realisation of one's identity with Brahman is Liberation possible, and by no other means. 

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 utter the name of the medicine, without taking it; (similarly) without direct realisation one cannot be liberated by the mere utterance of the word Brahman.

63. Without causing the objective universe to vanish and without knowing the truth of the Self, how is one to achieve Liberation by the mere utterance of the word Brahman ? — It would result merely in an effort of speech.

64. Without killing one’s enemies, and possessing oneself of the splendour of the entire surrounding region, one cannot claim to be an emperor by merely saying, ‘I am an emperor’.

65. As a treasure hidden underground requires (for its extraction) competent instruction, excavation, the removal of stones and other such things lying above it and (finally) grasping, but never comes out by being (merely) called out by name, so the transparent Truth of the self, which is hidden by Maya and its effects, is to be attained through the instructions of a knower of Brahman, followed by reflection, meditation and so forth, but not through perverted arguments.

66. Therefore the wise should, as in the case of disease and the like, personally strive by all the means in their power to be free from the bondage of repeated births and deaths.

Thus Sri Sankara clearly indicated that: - yoga, intellectualism, scriptural mastery is not the means to self-knowledge.  But by the realization of one's identity with consciousness, which is ultimate truth or Brahman, freedom from experiencing the illusion as reality is possible, and by no other means. 

Seeker of truth has to get rid of his doubts through deeper inquiry, analysis and reasoning on his own, to realize the fact that, the self is not the form but self is formless. Thus his analysis and reasoning has to be based on the formless not on the form.  By simply go on believing and accepting whatever said by the punditry will not lead one towards path of wisdom. All the doubt has to be got rid of "by the sword of Self - Knowledge."  The scriptures, yoga are not necessary if one follows the inner [formless] path.  Religion and yoga are not the means to path of wisdom. 

Limiting the Self to the ego (waking entity) and practicing meditation or Samadhi any other path on the base of ego (waking entity) is like trying to drain the ocean drop by drop.

The formless soul or consciousness is the innermost self, is birth- less, deathless and world -less eternal identity. The ‘Self’ is totality dual (waking or dream) and non-dual (deep sleep) experiences that is both conscious and unconscious and something that is always aware of coming and going of these dual and non-dual experiences(three states).

 The ego (waking entity) is not the self.  Limiting the Self to the ego (waking entity) and practicing meditation or Samadhi  any other path on the base of ego (waking entity)    is like trying to drain the ocean drop by drop. The soul, which is in the form of consciousness, is the innermost self. Consciousness transcends our ego and the mind which is in the form of universe. Universe appears as waking and dream. Thus limiting the self to’ ego or waking entity’ is cause of the ignorance.

Ignorance is cause of experiencing the duality (universe or waking) as reality. Waking is cause of experiencing the birth, life, death and the world as reality.  If experience of birth, life, death and the world (waking) is accepted as reality, than ignorance will prevail and if ignorance prevails wisdom will not dawn.   

That is why Sri, Sankara indicates in (VC):-

56. Neither by Yoga, nor by Sankhya, nor by work, nor by learning, but by the realisation of one's identity with Brahman is Liberation possible, and by no other means. 

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.

63. Without causing the objective universe to vanish and without knowing the truth of the Self, how is one to achieve Liberation by the mere utterance of the word Brahman? — It would result merely in an effort of speech.

65. As a treasure hidden underground requires (for its extraction) competent instruction, excavation, the removal of stones and other such things lying above it and (finally) grasping, but never comes out by being (merely) called out by name, so the transparent Truth of the self, which is hidden by Maya and its effects, is to be attained through the instructions of a knower of Brahman, followed by reflection, meditation and so forth, but not through perverted arguments.

66. Therefore the wise should, as in the case of disease and the like, personally strive by all the means in their power to be free from the bondage of repeated births and deaths.

Thus Sri Sankara clearly indicated that - yoga, intellectualism, scriptural mastery is not the means to self-knowledge.  But by the realization of one's identity with consciousness, which is ultimate truth or Brahman, freedom from experiencing the illusion as reality is possible, and by no other means.