‘Prana’ is a Sanskrit word for breath or ‘air inspired’ (from the verb ‘pran’: aspire), but also means ‘universal and invisible energy that enters the body through breathing’. Prana is a physical principle that permeates all forms of life, that which gives life and wisdom to beings and that is or comes from a kind of ‘universal spirit’.
The first mention of the word ‘prana’ appears in the Rig-Veda, the oldest text of India, in the mid-second millennium B.C.
Prana shares the global sense of ‘air-life-wisdom’ with many terms of different ancient cultures: Greek ‘psyché’ and ‘pneuma’, Hebrew ‘ruach’ and ‘néfesh’, Latin ‘spiritus’ and ‘anemos’, Arabic ‘ruh’... or the Hindu atman, which also means soul while air or breath. (See the post ‘Pneuma...’ of this blog). Often, too, prana is confused with jiva, another Sanskrit term for soul-air, as there is a close connection between them. Jiva, in particular, would be the portion of air or prana which is located specifically in the cavity of the heart, which tends to be associated with the structural physical body as opposed to the more voluble etheric body of prana, but they are essentially the same air. (One can get an idea of the meaning of prana -or atman, jiva...- consulting the Sanskrit-English Dictionary of Monier Monier-Williams.)
In Vedic tradition prana means ‘vital air’ or ‘life force’. In China it is known as ‘qi’, ‘ki’ in Japan, in Polynesia as ‘mana’. The fact is that it is understood that it is present throughout the universe, in the macrocosm (space) and the microcosm (body of living beings). Its proper flow to (and in) our bodies ensures our good health. Prana is the subtle material energy that arises from the universe and that functions as an interface between the physical body and the subtle or ethereal 'body' of mind, allowing all psychophysical functions (ie, the ‘animation’, from the Latin ‘anima’) .
According to ayurvedic medicine and yoga, prana flows through a network of channels called nadis. They are tubes (bronchi, arteries, veins...) through which flows the prana (inspired air). In the western hermetic interpretation, nadis are not just holes where the air flows into the body through breathing and blood circulation, but also hypothetical channels, called ‘akashic’ or ‘ethereal’ (being ‘akasha’ ether in Sanskrit). These channels would be distributed throughout the universe and also intertwined throughout our bodies, and through them would flow prana energy. As C. W. Leadbeater wrote, prana would be an energy that comes in inspired air, which flows through the nadis and that is used in some way through the cardiovascular system and the nervous system to bring soul and knowledge.
In Chinese medicine, especially acupuncture and its derivations, the equivalent of prana is qi. Qi is literally breath and mood, is an active principle forming part of any living thing which has to be understood as a ‘vital energy flow’. Qi is an air energy that continuously flows by nature, and a disruption of its free flow in the body is the basis of physical and psychological disorders.
Most oriental spiritual and therapeutic systems include attention to breathing or some breathing techniques. The main tool to understand qi is breathing. In Japanese, ki is sometimes translated as ‘energy, presence, will, health’. In some contexts the Japanese word ki translates directly by ‘breathing’. Through meditation on breath, or breathing techniques, it is claimed that you can develop the natural energy of your person and harmonize your personality and metabolism.
Some zen and budo masters say, moreover, that breath is the breath of cosmos, and that all elements of nature are a piece of whole, and reality is expressed in alternating opposite processes (which are called ‘yinyang’). Cosmos breathes while we breathe, alternately. In meditation, also, breathing is considered an expression of mood, as well as the link between emotions, thinking, instincts and physical states.