The Śākta Āgamas, more commonly known as the tantras, declare that the human body is a little universe in itself and that the various tattvas or cosmic principles in creation are there embedded in it. However, each of these tattvas has its own centre of activity, the place where it is most preponderant and from where its energies radiate into the system. They have been called ‘cakras’ (circles or centres) and have often been likened to lotuses. They are not anatomical centres like the nerve-plexuses but subtle seats of consciousness, of Śakti or divine Power.
Works on Yoga depict fourteen principal nāḍīs or subtle conduits for the flow of prāṇic energy, of which the suṣumnā, the iḍā and the piṅgalā are the most important ones. The suṣumnā is situated inside the spinal column and iḍā and piṅgalā entwine it from left and right. All the three start from the root of the spinal column and end near the centre of the head.
Six cakras are described as being situated in this Suṣumnā. They are mūlā-dhāra, svādhiṣṭhāna, maṇipūra, anāhata, viśuddha and ājñā. The seventh, the sahasrāra, is the final destination of the Kuṇḍalinīśakti, the basic power of the human organism which is likened to a coiled serpent lying dormant at the mūlādhāra, until it is roused by appropriate yogic exercises.
The mūlādhāracakra is situated in the space between the anus and the generative organ, at the root of the suṣumnānāḍī. It resembles a crimson lotus of four petals. It is the centre of the principle of earth—pṛthvītattva—and controls the sense-organ of smell as also feet, one of the organs of action. Brahmā, along with his Śakti Sāvitrī, is the presiding deity of this cakra.
The svādhiṣṭhānacakra, next in the series, is situated at the root of the genitals and is placed inside the suṣumnā. It resembles a lotus of vermillion colour with six petals. It is the centre of the principle of water—the aptattva—and controls the sense organ of taste and also the hands from among the organs of action. Viṣṇu along with his Śakti Rākiṇī, is the presiding deity of this centre.
Then comes maṇipūra, at the navel region. It resembles a lotus of dark hue (like the rain clouds) with ten petals. It is the centre of the principle of fire—tejastattva—and controls the sense-organ of sight and the organ of action, the anus. Rudra with his Śakti Lākinī is the presiding deity.
The anāhata, situated in the region of the heart, resembles a lotus of twelve petals of blood-red colour. It is the centre of the principle of air—vāyutattva—and controls the sense of touch and the genitals. Īśa with his Śakti Kākinī, is the presiding deity.
Next comes the viśuddhacakra, in the region of the base of the throat. It resembles a lotus of sixteen petals of smoky purple colour. It is the locus of the principle of ether—ākāśatattva—and controls the organ of hearing as also of speech. Sadāśiva with his Śākinī Śakti is the presiding deity.
Last of this series of cakras, often designated as ‘ṣaṭcakras’, is the ājñācakra situated in the region corresponding to the middle of the eyebrows. It resembles a lotus of two petals of white colour. It is the centre of the principle of mind. Śambhu with his Śakti Hākinī is the presiding deity.
Beyond this there is the sahasrāra-cakra, resembling a white lotus of a thousand petals, presided over by Parama-śiva himself. It hangs from the brahmarandhra (opening at the top of the skull) and above the suṣumnā, head downwards.
In fact all these cakras hang head downwards only, until they are pierced by the Kuṇḍalinī, after it is roused from its slumber by appropriate yogic practices. This piercing of the cakras by the Kuṇḍalinī is called ‘ṣaṭcakrabheda’. When the Kuṇḍalinī reaches the sahasrāra and gets united with Paramaśiva, the yogi will go into samādhi, the superconscious state, experiencing ineffable bliss.
The tantras also describe the various results that accrue to a person who contemplates on these cakras in the prescribed manner.