Yoga and jnana are the two wings of liberation. A hatha yogi starts his sadhana with the body and prana. A raja yogi starts his spiritual practice with the mind. A jnana yogi starts his spiritual sadhana with the buddhi, discriminative mind, and will. To be more accurate, a jnana yogi starts directly with Brahman, the Supreme Soul. He repeats constantly: Aham Brahmasmi I am Brahman. He who is attempting to fix the mind on Brahman is really doing the highest karma yoga, highest yajna, highest duty and highest charity. He need not visit pilgrimages. He need not distribute charity.
Tattwa jnana, knowledge of the true principle of truth, is release from the trammels of ones own mind, leading to moksha. The same mind which becomes of the nature of the universe through ajnana or ignorance, through spiritual practice and direction becomes of the nature of jnana, higher knowledge. If the mind is bathed in the water of jnana and cleansed of all its impurities, then the shining moksha will disclose itself in its native effulgence to those who strive after it. The real bliss is that which arises when the mind, divested of all desires through the eternal jnana, destroys its subtle form.
The aspirant in the jnana yogic path must be equipped with the four means of salvation, sadhana chatushtaya: vairagya, viveka, mumukshutva and shatsampat. They are necessary qualifications for a student of Vedanta. Not an iota of spiritual progress is ever possible unless one is really endowed with this fourfold qualification. These four means are as old as the Vedas or the world itself. Every religion prescribes these four essential requisites for the aspirant, only the names differ. Viveka is discrimination between the real and the unreal (sat and asat), permanent and impermanent (nitya and anitya), self and the non-self (atman and anatman). Viveka should not be an ephemeral or occasional mood in an aspirant. A viveki, person of discrimination, is always on the alert and never gets entangled in anything. Viveka gives inner strength and mental peace. From viveka is born vairagya.
Vairagya is dispassion but does not mean abandoning social duties and responsibilities of life. A vairagi, dispassionate person, has no raga-dwesha (attraction and repulsion). A worldly man is a slave of these two mighty currents. A dispassionate man has a different training. He has a different experience altogether. He is a master in the art or science of separating himself from the impermanent, perishable objects. A dispassionate person is the most powerful, happiest and richest person in the world.
Shatsampat, the six-fold virtues include shama, equanimity, dama, self-control, uparati, sensory withdrawal, titiksha, endurance, shraddha, faith and samadhana, constant concentration on reality. Of these six virtues, shama, dama and samadhana are really yogic practices to control the mind. Shama represents the chitta-vritti-nirodha of raja yogis by giving up of desires, dama corresponds to pratyahara. Samadhana is ekagrata of yogis.
Lastly, we come to the fourth of the main qualifications, mumukshutva. It is intense desire for liberation or deliverance from the wheel of birth and death with its concomitant evils of old age, disease, delusion, and sorrow. If one is equipped with the previous three qualifications of viveka, vairagya, and shat-sampat, mumukshutva will come by itself. The aspirant should practise all the four means to the maximum degree. There is a definite significance in the sequence of the four sadhanas. That aspirant who is in possession of the four means is a blessed divinity on the surface of this earth.
A complete detachment from the outward things, the manifold objects of senses, together with a capacity for metaphysical abstraction and concentration on inward things are demanded from an earnest seeker after truth. The voice of the pure spirit cannot be heard till all superficial organs cease to exist.
The aspirant must possess dauntless energy, for only through indefatigable effort can one realize Brahma jnana. Guru and the scriptures can show you the path and remove your doubts, but the aparoksha (direct, intuitive knowledge) is acquired only by individual effort. A hungry man, in order to satisfy himself, must eat. His hunger is not satisfied by watching another eat.
Brahma vidya or the science of the Self is not a subject that can be understood and realized by mere intellectual study, reasoning or ratiocination, or even by discussions and arguments. It is the most difficult of all sciences. Mere scholarly erudition or a high degree of intelligence cannot help one in the practical realization of the truth inculcated by this science. It demands perfect discipline, a discipline that is not to be found in modern universities and colleges, and solid sadhana for the achievement of the goal that is indicated by this para vidya or highest science.
Purification of the mind also will not bring about Brahma jnana. It is only a special intelligence, atmakara vritti or avichhinna vishesha chaitanya, that can destroy the moola ajnana, primitive ignorance, that envelops the swarupa (Brahman or Existence). This special intelligence is developed through meditation.
Agni, fire, is of two kinds, samanya agni or ordinary fire and vishesha agni or special fire. Samanya agni is hidden in all trees and woods. It is of no use for burning purposes. Vishesha agni that is formed by rubbing a match or rubbing two pieces of wood is useful for cooking and other purposes. Similarly, there is samanya chaitanya, ordinary intelligence or consciousness, that is pervading everywhere. There is also vishesha chaitanya or special intelligence. Samanya chaitanya cannot destroy ignorance or avidya.
To develop avichhinna vishesha chaitanya, you will have to take refuge in shravana, manana and nididhyasana hearing of shrutis, reflection and meditation on Brahman after purifying the mind. These are the three vedantic processes for the attainment of jnana. This is the ladder with three rungs through which the vedantin ascends to Brahman.
After the mind has been purified, an abstract image is formed in the purified mind by shravana and Brahma chintana. This abstract image melts later on into deep nididhyasana or profound and continued meditation. What is left behind is chinmatra or kevala asti (pure existence alone). Nididhyasana is meditation of atman. It is deep and intense contemplation. The mind is perfectly established in the Absolute. There is only one idea of Aham Brahmasmi. When this idea also is given up, nirvikalpa samadhi or sahaja advaita nishtha ensues. Just as salt melts in water, the sattwic mind melts in silence in Brahman, its substratum.
If you do shravana or hearing of the shrutis once, you must do manana or reflection on what you have heard ten times and a hundred times or a thousand times nididhyasana, profound and constant meditation. Then only real fruit is attained.