[raison d'etre = reason or justification for existence]
The act of breathing is a bridge between the internal and external Except the breath, there is nothing else which comes out as well as goes in.
That is why we have chosen breath to become the object of perception for our technique. Breath is the only tourist which tours the external space as well as the internal. It is the only light that enlightens the inside as well as the outside. If we desire our mind to stop wandering and to undertake an internal trip, the easiest way is to make it ride the chariot of breath and obtain access to the inside with it With the commencement of the internal trip, one will become an introvert and a spiritualist. This association of the mind with the breath is the easiest way to become spiritual.
The ancient methodology of controlling the mind and to keep it steady is to attach it to the breath. Engaged in the process of regulating the breath, mind itself becomes controllable and its restlessness vanishes.
Breath is very precious and one must not undervalue it as a petty thing. If one becomes competent to control this valuable phenomenon, one will reach greater heights in due course.
In the field of spiritual pursuit, breath serves as the foundation on which the superstructure of sadhana can be built Unless the foundation is strong, the superstructure cannot be stable.