The natural (uncontrolled) breath is connected to the body, the conscious mind and the unconscious mind. Therefore it develops not only calm concentration (Sanskrit: samadhi) but also awareness (Sanskrit: sati). It has two purposes: to strengthen the conscious mind and therefore develop calmness, will power and mental balance. Also to begin the process of releasing the knots of stored reactions in the unconscious. These knots create the negative habit patterns in the mind that prevent us from feeling peaceful and happy and drive us towards behavior that causes suffering for ourselves and others.
Meditation on the natural breath is central to the teachings of both Patanjali and Buddha. It is also mentioned frequently in the Bhagavad Gita and the Upanishads. It is the technique through which Buddha discovered the Four Noble Truths and became enlightened.
The natural breath as a meditation object has the following qualities, summed up as Choiceless Awareness of Present Reality.
This meditation works with the reality of the unconscious mind. The breath reflects the state of the mind. If the unconscious mind is agitated, this is mirrored in the breath. For example, if you feel angry you may notice that your breath has become hot, fast and coarse. Observing the breath trains the mind to work with reality rather than escaping into imagination or distraction. The process of observing the subtler aspects of the natural breath sharpens our awareness of the subtler levels of reality.
The breath is not a fixed reality but one that is constantly changing, one breath flows out and another flows in. This is significant as it reflects the changing nature of everything in existence and not only develops concentration (samadhi) but also sharpens the mind and develops our awareness levels (sati). It is a changing reality; each breath is new and different. Everything we experience in life is undergoing continuous change and therefore working with the breath trains us to respond equanimously to the phenomenon of change in life.
Our breath is always in the present. You cannot observe a past breath or a future breath. Usually our mind is running into the past or the future. To keep the breath in the present gives the mind enormous rest and relief, de-stresses it and therefore makes it more efficient. We can enjoy each moment to the full when we are fully present.
We cannot choose how we would like the breath to be, we have no preference towards it. It is devoid of any sound, form or contemplation of meaning. There is no conditioning, i.e. no liking or disliking for the breath. It is neutral and therefore it helps us to reach a natural attitude of objectivity and acceptance, the ability to accept reality as it is. This balance of mind allows us to not be destabilized by external circumstances but to be independently peaceful.
It does not belong to us
It is always with us and yet it does not belong to us. We do not have a feeling of ownership over our own breath. We do not try to hold on to the breath. We have to let it go at each exhalation therefore there can be no attachment to it. This helps to counteract our natural tendency to cling and be possessive in life. We cannot develop attachment to this meditation, unlike subjective meditation practices.