BRIHAD UP :-Even yoga cannot give perfect concentration and that the only way to gain it is philosophical realization.

It is impossible to stop thought for more than a  second whilst in the waking experience. If one succeeds in controlling thought and then banishes it, one passes into nirvikalpa samadhi, which is identical with deep sleep. The only difference between ordinary deep sleep and samadhi, therefore is that the ordinary man falls asleep involuntarily whereas the yogi has the satisfaction of knowing that he has passed into sleep by his own effort of will in banishing thoughts. 

Yoga can yield only duality, because everything that one can do or practice becomes a vanishing 'known.' It yields relative truth based on imagination, which is true from a physical viewpoint of view, not non-dual truth, which is ultimate reality.

Yogic truth is individual truth, not universal. The "Religions place God as the unknown reality” Every religious believer  has a different idea of God. Every man has a different idea of reality. Hence the need of definition before study. 

The yogic teachings about six chakras and seven chakras  of  Raja yoga is based on fact and fiction. It was noted that there were nervous plexuses and nodules at intervals in the spine and other parts of the body. Upon this basis the yogis started imagining that if the ego  is concentrated on each one a different mystic result would be obtained. But that is mere fancy. 

Mandukya Upanishads:- Those that want Brahman will not practice control of mind.  That is Yoga for duffers. The others will inquire and practice discrimination. (p.231)

Yoga and samadhi are not the goal but a means to an end, i.e. Gnana. Samadhi in itself is useless, because the mind is withdrawn and there is no memory of it until after it is over and one returns to waking state. Yogi who attains mind control: it is only sleep.  The world must be seen before you can know its true nature in Gnana. The yogi who shuts it out, thereby deprives himself of the opportunity to achieve Gnana. 

BRIH. UPANISAD:-  "Yoga does not yield truth or liberation."( page 32).

The Gnani sees the essential universal unity and the multiplicity of objects simultaneously. The person in deep sleep or samadhi leaves out the objects and sees the essence; hence he has not the full Gnana. There was no permanent cure however without Gnana, and Yoga does not yield Gnana. 

Sage Sri Sankara in commentary to "Brahma Sutras:- " "The highest beatitude is not to be attained by Yoga." (Sacred Books of East Series page 298 Vol.1.)   And he also says Samadhi is the same as sleep (p.312) ---this indicates that yoga is not the means to self-realization.  And yogic Samadhi is not non dual self-awareness. 

Patanjali warns against sleep as a hindrance to yoga, he means when it occurs in the early stages of the practice before one has obtained the power of control and consequently to banish thought. This fact that Samadhi is deep sleep is kept secret because people would not be tempted to take up yoga. Then what is the value of it? Why, to sharpen the mind, to enable it to keep away all extraneous thoughts when one gets out to reason in the practice of the next higher stage, i.e. Gnana. 

Mandukya UP:-  yoga can no more succeed than the ocean can be emptied with a blade of grass. 

Yoga is thus simply a sharpening-stone for the intellect to enable it to take up Gnana. People think that, the yogis  can  live  without thoughts but it is  impossible to live without the thoughts. How can he walk from one spot to another without thought? He does not know the Gnanic  or Advaitic  truth if he says thoughtlessness is the nature  of  the self. Yoga has its place rather than its value and that its value is for a certain type of mindset.  Yoga will give steadiness of mind, education of mind, but never Truth because it ignores the external world. 

BRIHAD UP :-Even yoga cannot give perfect concentration and that the only way to gain it is philosophical realization. (Page 133 1st para)

Patanjali takes for granted that there is an Iswara--God, gives it to the students  for concentration purposes, and then  they naturally find God in their  meditations. But it is only their imagined God. Mystics see what they are looking for or that whose existence they presuppose. Therefore Patanjali Yoga belongs to religion, not truth. Belief in Yoga  is a self-mesmeric condition out of which it is extremely difficult to escape. 

Religion and Yoga are useful from utilitarian view points, but from point of view of seeking truth they are useless. Religious believers  has  not proved that there is a God because the religious gods are mere belief.  Personal experience which is not universally valid is no proof, neither is ecstatic feeling.

 

All philosophical, yogic and cosmological teachings but at the end it finally says "All is imaginative and based on the false self (ego or waking entity) within the false experience(waking)." 

Sage Sankara says :-  Yoga is not the means of liberation. (P -132-133 of his commentary on Brihadaranyakopanishad).