Systematic development of the mind : Breathing
In training the mind the first step is to begin with the breathing. Regular breathing puts the body in a harmonious condition; and it is then easier to reach the mind. In practicing breathing, the first thing to consider is Âsana or posture. Any posture in which a person can sit easily is his proper position. The spine should be kept free, and the weight of the body should be supported by the ribs. Do not try by contrivances to control the mind; simple breathing is all that is necessary in that line. All austerities to gain concentration of the mind are a mistake. Do not practice them.
The mind acts on the body, and the body in its turn acts upon the mind. They act and react upon each other. Every mental state creates a corresponding state in the body, and every action in the body has its corresponding effect on the mind. It makes no difference whether you think the body and mind are two different entities, or whether you think they are both but one body — the physical body being the gross part and the mind the fine part. They act and react upon each other. The mind is constantly becoming the body. In the training of the mind, it is easier to reach it through the body. The body is easier to grapple with than the mind.
The finer the instrument, the greater the power. The mind is much finer and more powerful than the body. For this reason it is easier to begin with the body.
The science of breathing is working through the body to reach the mind. In this way we get control of the body, and then we begin to feel the finer working of the body, the finer and more interior, and so on till we reach the mind. As we feel the finer workings of the body, they come under our control. After a while you will be able to feel the operation of the mind on the body. You will also feel the working of one half of the mind upon the other half, and also feel the mind recruiting the nerve centres; for the mind controls and governs the nervous system. You will feel the mind operating along the different nerve currents.
Thus the mind is brought under control — by regular systematic breathing, by governing the gross body first and then the fine body.
The first breathing exercise is perfectly safe and very healthful. It will give you good health, and better your condition generally at least. The other practices should be taken up slowly and carefully.
Complete Works of Swami Vivekananda
Concentration and Breathing