The practitioner of Hatha Yoga sees that the psychological and spiritual state is very much under the control of the actions and powers of the physical body. When the body is not healthy, it is difficult to concentrate on spiritual pursuits. When the senses distract the concentration, it becomes impossible to focus on the higher levels of consciousness of existence. While other paths attempt to solve these issues in a variety of other ways and with other means, the Hatha yogin focuses his attention directly on the physical body and works to both understand it and gain mastery over it. This is done primarily through the two levers that are the primary mode of action in Hatha Yoga, namely the control of the physical instrument through use of specific asanas, or postures, that direct and control the flow and accumulation of energy within the body, and the use of specialized breathing techniques, pranayama, which harness the vital energy flow.
Sri Aurobindo describes the issue: “…but the physical being is made up of two elements, the physical and the vital, the body which is the apparent instrument and the basis, and the life energy, prana, which is the power and the real instrument. Both of these instruments are now our masters. We are subject to the body, we are subject to the life-energy; it is only in a very limited degree that we can, though souls, though mental beings, at all pose as their masters….Moreover, the action of each and both in us is subject not only to the narrowest limitations, but to a constant impurity, which renews itself every time it is rectified, and to all sorts of disorders, some of which are normal, a violent order, part of our ordinary physical life, others abnormal, its maladies and disturbances. With all this Hathayoga has to deal; all this it has to overcome; and it does it mainly by these two methods, complex and cumbrous in action, but simple in principle and effective.”
Sri Aurobindo, The Synthesis of Yoga, Part Two: The Yoga of Integral Knowledge, Chapter 27, Hathayoga, pp. 508-509