The Nadis are the channels through which flows prana. It is said that there are about 72,000 in our spiritual anatomy. Although they are tubes made of subtle matter and belong to our energy system, they have a decisive influence on our physical body.
The most important are called Ida, Pingala and Sushumna. The latter is located in what corresponds to the spine and connects to the sacrum to the skull. It is the central subtle nerve of our entire system. All other nadis originate in Sushumna, leaving Muladhara, the first of our chakras. On each side, as corresponding to the sympathetic ganglia of our material body, they are Ida and Pingala.
Ida is where flowing apana, negative manifestation of prana. It is a force related to the moon flowing down. It is connected to the left nostril with the left side of the body and the right brain. It is a force with feminine qualities, illustrated as white.
Pingala has masculine qualities and is related to the sun and is a positive polarity, flowing upwards. It relates to the right body, the right nostril and the left hemisphere of the brain. It has the power to generate heat while Ida is for low temperature.
When we do pranayama exercises and other practices of hatha yoga, these two forces balance and purify the Nadis, making it easier for the prana and quiets the mind. With the withdrawal of the senses (pratyahara), concentration (dharana) and meditation (dhyana), we are closer to the total silence of the mind. This is the main objective of raja yoga and pranayama for this reason is one of its eight practices.
Through pranayama exercises and asanas, we not only increase the amount of life energy we take, but we clean the channels through which flows the prana and also raise the cosmic kundalini energy we have at the base of the column as a sleeping snake. Kundalini rises when the prana and apana (the positive and negative of the vital energy, respectively) are in the first chakra, Muladhara. Swami Sivananda defined it as the union of prana and apana.
The chakras are centers of prana, or cosmic energy located in our astral body. As kundalini energy passes through each of these energy centers, different levels of consciousness are experienced. When kundalini reaches the seventh chakra, according to tradition, it comes to lighting, integration with the universal consciousness.
The first six chakras are located in Sushumna, the central channel of the energy system. The seventh is in the crown of the head. Each chakra represents a characteristic of our psychological and spiritual being and health of different parts of our physical body. The balance of our chakras reflects a full and harmonious life in different ways.
Each is symbolized by a similar illustration of a flower, which represents the number of nadis arising from there, and each nadi is associated with a vibrational sound emitted from kundalini energy when passing. In addition, each energy center has a mantra, a color and an element to which it is associated, and corresponds to a particular nerve plexus.
In yoga we close our eyes, we block outside distractions and turn our attention to ourselves. This is pratyahara, the withdrawal of the senses. It is one of the eight elements prescribed by the Yoga Sutras, written or compiled by Patanjali, a teacher of the second century BC.
It is the time when the true yoga begins, leading to the concentration, meditation and integration. It is the fifth element and possibly the decisive one. The above four are Yamas (restraints), Niyama (observance), Asana (postures), Pranayama (control of prana).
Pratyahara is to isolate the senses of external objects and allow them to be directed inwardly, home to the qualities of the universe. When we look out, the mind gets involved with changing events of the world. Usually, the senses are at the service of the experience and the mind is distracted by outside events and takes its shape. It is identified with the experience and seeks happiness in the outside world, in objects that produce it.
With the practice of Pratyahara, the mind directs and controls the senses which take the form of external objects and allow the mind to be calm and focused. With the withdrawal of the senses, there is no distraction or new mental activity of judgment, desire or rejection generated by the senses since Pratyahara directs the mind inward, which has been purified and harmonized through past practices i.e. the ethical principles, postures and breathing.
The land needed for suffering is the inability to discern what is real and what is not. So we confuse ‘what is impermanent, impure, anxious or empty with permanence, purity, happiness and be true’. We believe that truth is the outside world, changing, causing joy and sadness alike and we apprehend it through the senses. Swami Sivananda says that senses follow the mind as bees follow the queen says. The bees fly if the queen bee flies, and stop if she stops, the senses are restricted if the mind is restricted. When the mind is pure, sharp, and there is no control of the senses and the outside world, it no longer determines us.
Pratyahara is the first step to connect with our ultimate reality. The objects of the outside world lose their character of absolute reality and become a projection of consciousness. While external objects cease to attract us and we can focus attention more specifically to the body in the asanas and then to breathing in pranayama. There is discrimination between attention and the object that produces it.
If the above items are intended to purify the body and mind, and to build ethical precepts for the yogi, the last three are directed to the realization properly. Pratyahara is the transition to the perfect discipline of the last pillars of yoga and goes hand in hand with the next concentration. It is no coincidence that the classical form of yoga is called Raja Yoga, which is one of the qualities associated with the movement and hyperactivity of universe.
When we left the sphere of sense perception through the stillness in the asanas and pranayama, mind through a form of ethical life turn our attention inward and we are ready for a higher level of consciousness and here it is where yoga starts.