Now that the chakras have become New Age parlance, there are many interpretations of their meaning and function being bandied about. While this popularity is making the chakras a household word, it is also spreading a lot of confusing, conflicting, and often erroneous information. It is important to realize the chakras come from an ancient tradition, which many New Age teachers have barely explored. Here is a brief summary of the development of the chakras historically.
The Vedas, which are the oldest written tradition in India, (2,000 – 600 B.C.) were written largely by the Aryans, who were said to have entered India on chariots. The original meaning of the word chakra as “wheel” refers to the chariot wheels of the invading Aryans. (The correct spelling is cakra, though pronounced with a ch as in church.) The word was also a metaphor for the sun, which “traverses the world like the triumphant chariot of a cakravartin.” (ruler) and denotes the eternal cycle of time called the kalacakra, or wheel of time. In this way, it represents celestial order and balance.
It is said the cakravartins were preceded by a glowing golden disk of light, much like the halo of Christ, only this spinning disk was seen in front of them (perhaps their powerful third chakras?). The birth of a cakravartin was said to herald a new age. It is also said that the god Vishnu descended to Earth, having in his four arms a cakra, a lotus flower, a club, and a conch shell. (This may have referred to a cakra as a discus-like weapon.)
There is some mention of the chakras as psychic centers of consciousness in the Yoga Upanishads (circa 600A.D.) and later in the Yoga Sutras of Patanjali (circa 200 B.C.). Patanjali’s tradition was largely dualistic, however, stating that nature and spirit were separate, and that the goal of yoga was to rise above nature.
The chakras and Kundalini came to be an integral part of yoga philosophy in the non-dual Tantric tradition, which arose in the 7th century, in reaction to the dualist philosophy which preceded it. This tradition advised being in the world rather than separate from it. Tantra is commonly thought of in the West as primarily a sexual tradition, as Tantrism does put sexuality in a sacred context. Yet this is actually only a small part of a broad philosophy which includes many practices of yoga, worship of deities, especially the Hindu goddesses, and integration of the many polaric forces in the universe.
The main text about chakras that has come to us in the West is a translation by the Englishman, Arthur Avalon, in his book,The Serpent Power published in 1919. These texts: the Sat-Cakra-Nirupana, written by an Indian pundit in 1577, and the Padaka-Pancaka, written in the 10th century, contain descriptions of the centers and related practices. There is also another 10th century text, called the Gorakshashatakam, which gives instructions for meditating on the chakras. These texts form the basis of our understanding of chakra theory and Kundalini yoga today.
In these traditions, there are seven basic chakras, and they all exist within the subtle body, overlaying the physical body. Through modern physiology we can see that these seven chakras correspond exactly to the seven main nerve ganglia which emanate from the spinal column. There are two minor chakras mentioned in the ancient texts, the soma chakra, located just above the third eye, and the Anandakanda lotus, which contains the Celestial Wishing Tree (Kalpataru) of the Heart Chakra.
(This information is to the best of my understanding. If anyone has anything to add to it or finds incorrect information, please email me.)