Govindam Bhaja Mooda Mathe

During his stay in Kashi, Adi Shankaracharya noticed a very old man studying the rules of Sanskrit by Panini. Shankara was touched with pity at seeing the plight of the old man spending his years at a mere intellectual accomplishment while he would be better off praying and spending time to control his mind. Shankara understood that the majority of the world was also engaged in mere intellectual, sense pleasures and not in the divine contemplation.

Shankara says in Bhaja Govindam that all knowledge other than the Self knowledge is useless. What good is lust when youth has fled? What use is a lake which has no water? Where are the relatives when wealth is gone? Where is samsara, the world, when the truth is known?

In Vivekachudamani, Shankara explains about Sadhana Chatushtaya, the four-fold path for realization of the self through Jnana Yoga. Its four pillars are identification of the real truth (Viveka), mental detachment from false illusions (Vairagya), the sixfold qualities of perfection (shat-sampat) and intense desire for liberation (Mumukshutva). With realization comes answer to the question Who am I?.

Viveka is the discrimination of real from unreal, between limited world and unlimited Brahman, between self and non-self, between eternal and the non-eternal (nitya anitya vastu viveka), between Atman and Anatma etc. Viveka comes to a person who is having a steady intellect (sthithpragya) and who has done good karmas in his previous birth as well. To live in Yoga is to live with discrimination. The firm conviction that Brahman alone is real and that the universe is illusory (mitya) is discrimination between the eternal and the non-eternal.

Vairagya is mental detachment from all worldly objects. It does not mean abandoning one's social duties and responsibilities of life and live in a solitary cave of the Himalayas. He appears to be a normal human from outside, but deep within he is detached from the world and connected with the divine.
Krishna said in Gita - When one relinquishes all the desires arising in the mind, O Arjuna, when one is satisfied in oneself with the self, then one is said to be of steady wisdom (sthita-prajna). One whose mind is not perturbed by pain, who does not hanker after pleasures, who is free from desire, fear and anger — is called a sage of steady intellect. When one is able to withdraw the senses from the objects of senses on every side, as a tortoise withdraws its limbs, then one's wisdom is firmly established.
Vairagya born of Viveka only will be of a lasting nature. Such a Vairagya only will be helpful to you in your spiritual practices. Karana Vairagya due to setbacks in life will be temporary.

shat-sampat is the six virtues of perfection (shama, dama, uparati, titiksha, shraddha and samadhana) to obtain mental control and discipline.
Sama is peace, calmness of mind which is achieved by withdrawing the mind from all sense-pleasures and through the eradication of desires. The mind can become calm only when there is Viveka and Vairagya.
Dama is control over senses (jnaanendriya and karmendriya). The Indriyas cannot work independently. They can work only in conjunction with the mind. If the mind is checked, the Indriyas will come under control automatically. The mind will come under control very easily if Dama also is practised. The Indriyas can be withdrawn more effectively by the process of double withdrawal, by withdrawing the mind and the Prana at the same time. It is the mind that moves the Indriyas. It is the Prana that energises the Indriyas. Dama is restraint or rational control of the senses.
Uparati is renunciation or self-withdrawal. it is resolutely turning the mind away from desire for sensual enjoyment. This state of mind comes naturally when one has practiced Viveka, Vairagya, Sama and Dama.
Titiksha is the power of endurance. Enduring all adversities without lament or anxiety and without seeking to counter them is titiksha. An aspirant should patiently bear the pairs of opposites such as heat and cold, pleasure and pain, etc. Forbearance of all misery, without even a thought of resisting or driving it out, without even any painful feeling in the mind, or any remorse — this is Titiksha.

Sraddha is intense faith in the word of the Guru, in Vedantic scriptures, God and, above all, in one's own self. It is not blind faith but is based on accurate reasoning, evidence and experience. As such, it is lasting, perfect and unshakable. Such a faith is capable of achieving anything.
Samadhana - The mind remaining firmly fixed in Brahman, without allowing it to run towards objects, is samaadhana. The mind is free from anxiety amid pains and troubles.

Mumukshutva is intense desire for liberation. When purification of mind and mental discipline are achieved, the longing for liberation dawns by itself. The sloka 32 of Vivekachudamani says, among the various means for liberation, bhakti is the greatest. Bbhakti is not about devotion or loyalty to God. Bhakti is the continuous contemplation of ones essential nature or swa svarupa anusandhaana. The 3-fold process of Shravana, Manana and Nididhyasana leads one to complete awakening and realization.