Howsoever we define pranayama, that is to say, whether we make kumbhaka an indispensable part of it or not, one essential feature of pranayama according to any definition, is, that it involves a control of breath. Breath is called prana in Sanskrit. Prana also means the soul. In the word pranayama prana does not mean the soul, but the breath The association of these two meanings of the word prana is obviously quite close. Breath and life go together. When any living being dies, breathing stops. This close association between breath and the soul attracted the attention of the ancient Aryans more, because they believed in a cycle of rebirths, until the soul became emancipated by attaining moksha or mukti.
This is called the belief in transmigration of the soul. This belief is very clearly expressed in the following slakes of the Bhagavadgita:
``Just as one throws away old clothes and takes new ones, so, too, the soul, i.e., the dweller in the body, leaves old bodies and enters into new ones." (Gita: II.29)
"Whosoever is born is sure to die, and one who dies is sure to be born again. This cycle is unavoidable. Hence it is no use being unhappy about it." (Gita: Il.27)
The observation that so long as one is breathing one is living, and that when the breath stops life comes to an end, accompanied by the belief that the soul transmigrates from birth to birth, must have played an important role in the initial ideas about pranayama. Our ancients first came to see that for the preservation of life we must preserve breath, and preserving breath entails two things, i.e., breathing slowly, and then not breathing (for a short time) at all. This idea was further strengthened by the belief that the length of one's life is to be measured not in terms of days or years, but in terms of how many times one is destined to breathe. From the fact that the stoppage of breath and the end of one's life coincide, our ancients probably conceived the idea that when the number of breaths one was destined to take was exhausted, one could not live any longer. This idea is conveyed even today in phrases like 'breathing one's last,' for indicating death.
It may be that the origin of pranayama, as is clear from the above references, was influenced by the idea of conquering death through the control of breath. But later on many other advantages must also have come to light. We shall have occasion to consider them at a later stage.