The  transformation of her husband into a sannayasi distressed Bharati to  no end. Wise and prudent as she was, she kept her counsel and  addressed Shankara thus: “You do know that the sacred texts enjoin  that a wife forms one-half of a husband’s body (ardhangini:  ardha - half; angini - body). Therefore, by defeating my lord, you have but won over only  half of him. Your victory can be complete only when you engage in  debate with me also, and manage to prove yourself better.”

Ubhaya  Bharati was a learned scholar herself and a very clever one at that.  Knowing very well that Shankara was a strict celibate, she asked him  how can a sanyasi, who has no experience as a citizen, and a  householder, claim complete knowledge?  She immediately started  discussing relationships and marital obligations. Shankara  confessed that he had absolutely no knowledge in this area, because  he was a celibate. However, Ubhaya Bharati felt that she should give  Shankara some time to study about this topic before resuming the  debate. Shankara immediately accepted the offer and left to start his  studies.

Through  his yogic powers Shankara came to know of a certain king who was  about to die. He instructed his disciples to preserve his body, which  he temporarily left to enter the dying king’s body. The king  happened to be a very evil man. Yet his wives were loyal to him and  were in tears when the king was in his deathbed. Suddenly, when the  king’s body woke up, one of the wives noticed that the king had  recovered under rather mysterious circumstances and appeared to have  become a changed man.

Shankara  learnt from that woman, all that he needed to know about man-woman  relationship and experiences. On his way out of the body he blessed  that lady who had taught him so much. Empowered with this newfound  knowledge, Shankara returned to resume the debate with Ubhaya  Bharati. This time, he was clearly unbeatable. Ubhaya Bharati and  Mandana Misra bowed their heads in humility and accepted defeat and  became followers of Adi Shankara and staunch vedantins.

Mandana  Misra was given Sanyasa dikha and was given name "Sureshwara".  Shankara imparted to Mandana Misra the Mahavakya 'Tat tvam asi'.  Shankara having thus brought the celebrated Mandana  into his own fold started again on his  mission.

Sri  Sureshwaracharya was the most talented disciple of Shankara  Bhagavatpada. He was placed as the First Head of Sringeri Sharada  Peetham in the South, one of the Mutts established by Shankara. He  was the greatest scholar after Shankara in those times. He was elder  to Shankara in age. He is also called as "Vartikacharya."  He wrote commentary on Shankara's Brahma Sutra Bhashyam, Dakshina  Murthy Stotram..

Ubhaya  Bharathi wanted to finish her avatara and go back to her abode. Shankara prays to her and requests her to  bless people on earth. It is Ubhaya Bharathi who is considered to be  blessing the devotees as Sharadamba from Sringeri.

GIST OF THE  GREAT DEBATE

As the  debate between Mandana Misra and Shankara, the two great stalwarts  lasted for a very long duration its content is very wide in its  spread and deep in its treatment. The following is the gist of these  mammoth discussions.

Initiating  the debate Shankara put forward the unity of all existence as  follows. “Brahman, the Existence-Consciousness- Bliss Absolute  (sat-chit-ananda ghanam) is the one ultimate Truth. It is He who appears as the entire world  of multiplicity owing to dense ignorance, just as a shell appears as  a piece of silver. Just as, when the illusion is dispelled the silver  is sublated by, and dissolved into its substratum, the shell, so too,  when ignorance is erased the whole world is sublated and dissolved  into the substratum, Brahman, which is the same as one’s own Atman.  This is supreme knowledge as well as liberation. It brings about  cessation of future births. The Upanishads which form the crown of  the Vedas are the authority in support of this proposition. I am sure  to prove this and be victorious in the debate. If, however, I am  defeated, I shall cease to be a Sanyasin, abandon the ochre robes,  and assume the white dress. Let Ubhaya Bharati be the umpire to  determine success or failure.”

In reply to  this statement, Mandana Misra made his contention as follows. “The  Vedantas or the Upanishads cannot be a proof of some thing which is  intangible i.e. Pure Consciousness, unoriginated and infinite, which  has no subject-object distinguishing feature. For words can reveal  only objects which are originated entities but never an abstract  feature called Consciousness. Therefore, the non-vedantic part of the  Vedas dealing with effects produced by works i.e. karma  kanda is the real verbal testimony. In the  light of performance of the actions in the form of rituals alone are  the steps leading to moksha or liberation. If I happen to be defeated in argument, I shall take  to the life of Sanyasa. As requested by you let my wife, Ubhaya  Bharati, be the judge for the contest”.

Agreeing to  the conditions put for ward by each other, the contestants started  the debate witnessed by the learned sages and even celestials.  Quoting from the Vedas as their authority and supported by  enlightened arguments the debate went on for several days.

The  arguments became keener and more complex, and the refutations and  denials also became correspondingly stronger and bolder. Both the  contestants raised more and more intricate questions. There was a  downpour of assertions and objections from either side. Quotations  from the scriptures were marshaled with marvelous skill by both, and  exploited to lend support to their case. And the debate went on.  Neither side could humble the other.

The  Acharya-Mandana dialogue was of such eloquence, scholarship and  profundity that even the Gods assembled over Mandana's house and from  above, remaining hidden from view, listened attentively to the  debate. In this way, the debate was carried on for several days. As  the days went by, Mandana started finding it difficult to maintain  his position and give proper replies to Shankara’s objections.  Thereupon, Mandana, instead of defending his thesis, commenced  attacking Advaita doctrine expounded in the Upanishads as put forward  by Shankara. The sum and substance of the objections and the replies  of the rivals are as under.

Both Mandana  and Shankara accept the authority of the Vedas as the revelation  standing for the ultimate good of man. Mandana’s school ( Purva  Mimamsa) holds that the only purpose of the  Veda is to prompt man to actions i.e. rituals sanctioned by the Veda  by performance of which man attains heavenly felicity of long  duration at the end of which he returns to earth – again to acquire  more merits by performing karmas. So the real nature of the Veda is of the nature of the commandments  to actions of a ritualistic nature. If there are purely descriptive  passages in it, these are descriptions of certain aids to karma like  its ingredients, agents required or eulogy of the rituals etc. All  such passages are to be considered as subordinate to the commandments  instituting rituals. Thus the whole of the Veda is an injunction for  performance of rituals and if this is not accepted the Veda becomes a  mere trash, a purposeless literature.

Contrary to this view are the views of Uttara-mimamsakas (Vedantins) led by Shankara.    They contend that the Veda has two  sections – karma kanda (ritualistic section) and jnana kanda (philosophic or knowledge section). The  latter is the crown of the Veda. What the ritualists say is true of  only the karma kanda and not of the Veda as a whole. The jnana  kanda consisting of the Upanishads (also  known as Vedanta) reveal the real or the ultimate meaning of the Veda  and the karma kanda portions are merely preparatory to this. Therefore to extend the  philosophy of ritualism to the understanding of the Upanishads is a  great blasphemy. The statements of the Upanishads are not  commandments for any action but revelations of the nature of the  Ultimate Reality and man’s relation to it. They are an end in  themselves and not aids to the performance of any ritual. The  understanding conveyed by them releases man from the false sense of  duality and establishes him in the experience of the Unity of all  existence (advaitam:  non-duality) thus releasing him for ever from the repetitive process  of births and deaths (samsara) by  rousing in him the sense of oneness with Eternal Bliss”.

To put  briefly, for Mandana and his school of thought Veda is revelation  teaching and prompting man to perform efficacious rituals to get  perishable felicities while for Shankara and his school of followers  the same revelation of the Veda is a philosophy, an understanding of  which establishes him in Eternal Bliss, the unity of all existence, moksha or liberation.  Ubhaya Bharati, the umpire, accepted the cogent arguments of Shankara  and over ruled the contentions of Mandana Misra thereby defeating  him, her own husband. The rest was history as already described.

CONCLUSION
From the  foregoing account of the discussion the following facts emerge.

1. Quoting various authorities and supporting the same with weighty arguments the contest was conducted in a highly dignified manner producing more light than heat, the contestants showing due respect to each other.
2. Women were held in high esteem and noted for their scholarship and erudition and more so because of their impartiality and      fair-mindedness.
3. The guru-shishya relationship between Shankara and Sureshwara proves the dictum in the Dakshina Murthy Stotram that a Guru can be young and a Shishya can be old and that such association has got nothing to do with age of the persons concerned

Also read
1. Six schools of Indian philosophy
2. Shad Darshanas – Six systems of Hindu philosophy