‘Verily, there is no purifier in this world like knowledge,’ says the Bhagwad Gita, 4:38.
While Hath Yog strengthens the body through systematic physical activity and breathing exercises, Bhakti Yog purifies the heart by unswerving devotion to god, and Karma Yog renders nobility to actions, Jnana Yog illuminates consciousness through self-enquiry, study of scriptures and meditation. Bhadragiriyar, 14th century Tamil poet-mystic, says: ‘It is knowledge which knows knowledge through knowing knowledge.’
Jnana Yog, also called Jnana Marg, path of knowledge, wisdom, Buddhi Yog, discipline of intelligence, and Brahmn Vidya, science of Brahmn explains the difference between the Self and non-self, the knower and known, the permanent and transient. Adi Shankaracharya held that since Brahmn is eternal, pure, of the nature of knowledge; and free, one should experience it.
Perception, inference, and scriptural testimony have been traditionally described as the sources of knowledge. Knowledge is both para, infinite, and apara, finite. The former relates to the higher dimension of being, the latter to the changing phenomena. Para liberates, apara binds one to the spatio-temporal world.
Jnana Yog enlightens one about the true nature of existence, identity of Brahmn and jivatma, individual soul, the five koshas, layers of the soul -- physical, vital, mental, wisdom and bliss -- the chakras, whirling energy-centres of the subtle body, and the ultimate purpose of life. He who cultivates the virtues of vivek, discriminative wisdom; vairagya, detachment; and abhyas, practice; can control his senses with reins of the mind. He can perceive the cosmic self in individual self, cosmic mind in individual mind, and cosmic consciousness in individual consciousness.
Yet, Jnana Yog is not merely an intellectual pursuit, since its goal is to transcend the mind which is ‘limited in its vision’ and ‘rigid in its conceptions’. Intellectual engagement with the Supreme Reality is not enough till one realises oneness with all life-forms and integrates the individual self with divine consciousness.
Jnana Yog postulates three ways to grow in spirituality: shravana, listening about the ultimate truth from one who knows it; manana, reflecting about the truth heard, and nididhyasana, meditation on the truth. The spiritual practitioner undergoes four stages: seeking, knowing, becoming, and being. He offers his senses and life-energy as oblations ‘in the fire of the yog of self-control, kindled by knowledge’ Gita 4:27. He is then free from vices and liberated while living.
Birth and death relate to the corporeal being on its journey to the Infinite in endless cycles. According to Brihadaranyak Upanishad, when one realises the Absolute Truth, one sees without seeing, smells without smelling, tastes without tasting, speaks without speaking, hears without hearing, touches without touching, thinks without thinking, knows without knowing, for there is nothing separate from Him. Knowledge about Brahmn in whom all polarities meet, is ‘the highest goal of life’, ‘the highest glory’, ‘the highest world’ and ‘the highest bliss’. As one progresses in knowledge, one moves from external to internal forms of worship, and finds the One Reality shining as the many.
The yogic paths of Jnana Bhakti and Karma are interconnected in a subtle way. Theistic schools, whether Vaishnava, Shaiva, Shakta, or Smarta, emphasise one path over the other, or synergise them, but their basic purpose is the same – to realise god in whatever form it is perceived.