The word kundalini is a familiar one to all students of yoga, as it is well known as the power, in the form of a coiled serpent, residing in mooladhara chakra, the first of the seven chakras. The other six are swadhisthana, manipura, anahata, vishuddhi, ajna and sahasrara, in this order.
All sadhanas in the form of japa, meditation, kirtan and prayer as well as all development of virtues, and observance of austerities like truth, non-violence and continence are at best calculated only to awaken this serpent-power and make it to pass through all the succeeding chakras beginning from swadhisthana to sahasrara.
Sahasrara is otherwise called the thousand-petalled lotus, the seat of Sadashiva, the Parabrahman or the Absolute. It is separated from the kundalini or the Shakti which lies at mooladhara, and in order to unite, the kundalini passes through all the chakras, as explained above, conferring liberation on the aspirant who assiduously practises yoga or the technique of uniting her with her Lord, and who gets success also in his effort.
In worldly-minded people, given to enjoyment of sensual and sexual pleasures, this kundalini power is sleeping because of the absence of any stimulus in the form of spiritual practices. The power generated through such practices alone awakens the serpent-power, and not any other power derived through the possession of worldly riches and affluence.
When the aspirant seriously practises all the disciplines as enjoined in the shastras, and as instructed by the preceptor, the veils or layers enmeshing kundalini begin to be cleared and finally are torn asunder and the serpent-power is pushed or driven, as it were upwards. Only a person in whom the kundalini has already been awakened and reached its abode or Sadashiva, and is blessed by this achievement alone becomes entitled to act as a Guru or spiritual preceptor, guiding and helping others also to achieve the same end.
Super sensual visions appear before the mental eye of the aspirant, new worlds with indescribable wonders and charms unfold themselves before the yogi, planes after planes reveal their existence and grandeur to the practitioner. The yogi gets divine knowledge, power and bliss, in increasing degrees, when kundalini passes through chakra after chakra, making them to bloom in all their glory, which lies concealed from the eyes of worldly-minded people who would refuse to believe of their existence even. Before the touch of kundalini, they do not give out their powers, emanating their divine light and fragrance and reveal the divine secrets and phenomena.
When the kundalini ascends one chakra or yogic centre, the yogi also ascends one step or rung upward in the yogic ladder; one more page, the next page, he reads in the divine book. As the kundalini travels upwards, the yogi also advances towards the goal of spiritual perfection in relation to it. When the kundalini reaches the sixth centre or the ajna chakra, the yogi gets the vision of the personal God or Saguna Brahman.
When the serpent-power reaches the last, the top centre, the sahasrara chakra or the thousand-petalled lotus, the yogi loses his individuality in the ocean of satchidananda or the existence-knowledge-bliss absolute and becomes one with the Lord or Supreme Soul.
He is no longer an ordinary man, not even a simple yogi, but a fully illumined sage, having conquered the eternal and unlimited divine kingdom. He is a hero having won the battle against illusion, a mukta or liberated one, having crossed the ocean of ignorance or the transmigratory existence, and a superman having the authority and capacity to save the other struggling souls of the relative world. Scriptures hail him most, in the maximum possible glorifying way, and his achievement. Celestial beings envy him, not excluding the Trinity: Brahma, Vishnu and Shiva.
Kundalini yoga actually belongs to tantric sadhana, which gives a detailed description of this serpent-power and the chakras, as mentioned above. Mother Divine, the active aspect of the existence-knowledge-bliss absolute, resides in the body of men and women in the form of kundalini. The entire tantric sadhana aims at awakening Her, and making Her unite with the Lord, Sadashiva, in sahasrara, as described in the beginning in detail. Methods adopted to achieve this end in tantric sadhana are japa of the name of the Mother, prayer and various rituals.
Hatha yoga also builds up its philosophy around this kundalini and the methods adopted in it are different from tantric sadhana. Hatha yoga seeks to awaken this kundalini through the discipline of the physical body, purification of nadis and controlling the prana. Through a number of physical poses called yogasanas it tones up the entire nervous system and brings it under the conscious control of the yogi. Through bandhas and mudras it controls the prana, regulates its movements and even blocks and seals it without allowing it to move. Through kriyas it purifies the inner organs of the physical body and, finally, through pranayama it brings the mind itself under the control of the yogi. Kundalini is made to go upwards towards sahasrara through these combined methods.
Raja yoga mentions nothing about this kundalini, but pro-pounds a still subtler, higher path, philosophical and rational, and asks the aspirant to control the mind, to withdraw all the senses and to plunge in meditation. Unlike hatha yoga which is mechanical and mystical, raja yoga teaches a technique with eight limbs, appealing to the heart and intellect of aspirants.
It advocates moral and ethical development through its yama and niyama, helps the intellectual and cultural development through swadhyaya or study of holy scriptures, and satisfies the emotional and devotional aspect of human nature by enjoining to surrender oneself to the will of the Creator. Raja yoga has an element of mysticism by including pranayama as one of the eight limbs. Finally it prepares the aspirant for unbroken meditation on the Absolute through a penultimate step of concentration.
Neither in philosophy nor in its prescription of methods does raja yoga mention kundalini, but it sets the human mind and chitta as its targets to be destroyed as they alone make the individual soul forget its real nature and brings on it birth and death and all the woes of phenomenal existence.
When we come to Vedanta, there is no question about kundalini or any type of mystical and mechanical methods. It is all enquiry and philosophical speculation. According to Vedanta the only thing to be destroyed is ignorance about one’s real nature, and this ignorance cannot be destroyed either by study, or by pranayama, or by work, or by any amount of physical twisting and torturing, but only by knowing one’s real nature, which is satchidananda or the existence-knowledge-bliss.
Man is divine, free and one with the Supreme Spirit always. This he forgets, and identifies himself with matter, which itself is an illusory appearance and a super imposition on the spirit. Liberation is freedom from ignorance and the aspirant is advised to constantly dissociate himself from all limitations and identify himself with the all-pervading, non-dual, blissful, peaceful, homogeneous spirit or Brahman.
When meditation becomes intensified, in the ocean of Existence the individuality is blotted or blown out completely. Just as a drop of water let on a hot frying pan is immediately sucked and vanishes from cognition, the individual consciousness is sucked in by the Universal Consciousness and is absorbed in it.
According to Vedanta there cannot be real liberation in a state of multiplicity, and the state of complete Oneness is the goal to be aspired for, towards which alone the entire creation is slowly moving on.