by Swami Sivananda
1. What is Pranayama
That (Asanajaya) being acquired, follows Pranayama or the control of breath - the cessation of the movements of inspiration and expiration.
Pranayama is said to be the union of Prana and Apana. Pranayama, in the language of Yoga, means the process by which we understand the secret of Prana and control it. He, who has grasped this Prana, has grasped the very core of cosmic life and activity. He who has conquered and controlled this very essence, has not only subjected his own body and mind, but every other body, mind and power in this universe. Thus, Pranayama or the control of Prana is that means by which the Yogin tries to realise in this little body the whole of cosmic life, and tries to attain perfection by getting all the powers in the universe. His various exercises and training are for this end. A comprehensive knowledge of Prana and its function is absolutely necessary for Pranayama. Here, I will give you a short description. For detailed information and different exercises, refer to my book Science of Pranayama.
2. What is Prana
He who knows Prana knows the Vedas, is the important declaration of the Srutis. You will find in the Vedanta Sutras, For the same reason, breath is Brahman. Prana is the sum total of all energy that is manifest in the Universe. It is the sum total of all the forces of nature. Heat, light, electricity, magnetism are all the manifestations of Prana. All forces, all powers and Prana spring from the fountain or common source - Atman. Whatever you behold in this sense-world, whatever moves or works or has life, is but an expression or manifestation of Prana. The Prana is related to the mind and through mind to the will and through will to the individual soul, and through this to the Supreme Being. If you know how to control the little waves of Prana working through the mind, then the secret of subjugating universal Prana will be known to you. That which moves the steam engine of a train and a steamer, that which makes the aeroplane glide in Akasa, that which causes the motion of breath in lungs, that which is the very life of this breath itself is Prana.
Pranavadins or Hatha Yogins consider that Prana-Tattva is very superior to Manas-Tattva, the 'mind-principle.' They say, Prana is present even when the mind is absent during slumber. It is through the vibrations of psychic Prana that the life of the mind is kept up and thought is produced. You see, hear, talk, sense, think, feel, will and know through the help of Prana. Prana is the very essence of cosmic life, that subtle principle which evolves the whole universe into its present form and which is pushing it towards its ultimate goal. The Prana may be defined as the finest vital force in everything which becomes visible on the physical plane as motion and action and on the mental plane as thought.
Though Antahkarana is one, yet it assumes four names, viz., Manas, Buddhi, Chitta and Ahamkara according to the different functions it performs. Likewise, though Prana is one, it assumes five forms, viz., Prana, Apana, Samana, Udana and Vyana according to the different functions it performs. This is termed as Vritti Bheda. The principal Prana is called Mukhya Prana. The function of Mukhya Prana is respiration; Apana does excretion; Udana does deglutition; Vyana performs circulation of blood; and Samana does digestion.
3. Yoga Nadis
Nadis are the astral tubes made up of astral matter that carry the subtle Prana. It is through these Nadis that the vital force of Pranic current moves. Since these are made up of subtle matter, these cannot be seen by the naked eyes. These Yoga Nadis are not ordinary nerves, arteries and veins that are known to Vaidya Sastra. The body is filled with innumerable number of Nadis that cannot be counted. Nadis play a vital part in this Yoga. These subtle tubes - Yoga Nadis - have influence in the physical body.
Wherever there is an interlacing of several nerves, arteries and veins, that centre is called as Plexus. Similarly there are plexuses or centres of vital forces in the Sukshma Nadis. These are called as Chakras or Padmas. All Nadis spring from Kanda. It is in the junction where the Sushumna Nadi is connected with the Muladhara Chakra. Of the innumerable Nadis, Ida, Pingala and Sushumna are the most important. Ida and Pingala Nadis are on the two sides of the spinal cord and Sushumna is within the spinal cord. Ida operates through the left nostril and Pingala through the right nostril. When the breath operates through Sushumna, the mind becomes steady. This steadiness of mind is termed Unmani Avastha, the highest state in Raja Yoga. If you sit for meditation when Sushumna is operating, you will have wonderful meditation. When the Nadis are full of impurities, the breath cannot pass through the middle Nadi. So, one should practise Pranayama for the purification of Nadis.
5. Prana and Mind
The mind of a man can be made to transcend ordinary experience and exist on a plane higher than that of reason known as superconscious state of concentration and gets beyond the limit of concentration. He comes face to face with facts which ordinary consciousness cannot comprehend. This ought to be achieved by proper training and manipulation of the subtle forces of the body, so as to cause them to give an upward push to the mind in the higher regions. When the mind is so raised into the superconscious state of perception, it begins to act from there and experience higher facts and higher knowledge. Such is the ultimate object of Yoga. The control of the vibratory Prana, means to a Yogin, the kindling of the fire of Supreme Knowledge, the realisation of the Self.
6. Prana and Breath
That which travels in the nerves of the physical body is gross Prana. That which moves in astral tubes or Yoga Nadis of the astral body is subtle Prana or psychic Prana. Breath is an external effect or manifestation of gross Prana. There is intimate connection or close relationship between the gross Prana and subtle Prana. Otherwise Hatha Yoga is impossible. Just as the stoppage of the fly-wheel of an engine brings about the stoppage of all other wheels in a factory, so also, the control or stoppage of the external breath leads to the efficient stoppage or control of the whole gross and subtle Prana of the physical and mental factories. Hence Pranayama exercises are practised.
If mind and Prana cease to exist, then thought will not arise in any way. Both these are one only, like the flower and its odour or a sesamum seed and the oil in it. Prana and mind stand to one another in the relationship of the supporter and the supported. If either of them is slain, then the other also will cease to exist. The destruction of both will confer Moksha on all. The function of mind belongs to Prana; from Prana or life proceeds all (Chhandogya Upanishad V: 14 & 15). If Prana departs from the body, all functions of organs cease immediately.