Yoga is intimately related to life and living. It is difficult to equate it with only one aspect of life – physical, intellectual, emotional, etc. though in Yoga all these areas are involved in different ways. In ancient times people experimented and arrived at certain modes of living, which they found more proper for leading one to a better life.
Thus, Yoga represents the way of life which endows perfect health in physical, mental, moral and spiritual levels. To achieve this great art and science of life, a comprehensive and practical system of self-culture has been formulated which brings harmonious development of one's body, mind and psychic potencies, that ultimately leads to physical well-being, mental harmony, moral elevation, self-confidence and habituation to spiritual consciousness.
The methodical study of scientific Yoga thus rightly begins with a disciplinary training of habits, actions, speech and thoughts in order to positively condition the mind followed with physical and postural training and rhythmic breathing to bring flexibility and muscular strength to the body. Then follows respiratory and nervous control that enables an individual to regulate his or her biological living by conservation and control of the bio-energy (prana). With this a higher level of immunity is achieved.
After physiological training comes the psychosomatic training with a view to controlling the external and internal senses which affect the equanimity and peace of mind. This is achieved through a series of graded physiopsychic efforts by relaxation, centralization, visualization, dissociation, introversion and meditation.
Through autosuggestion and contemplation on the negative and positive virtues a man can cultivate a universal outlook in his practical way of life rising above all the inhibitions and environmental influences common to human nature. Progressively the purity of the human nature and healthy mindedness is achieved through good physical health and control of the senses. It also includes methods of applied psychology, psychoanalysis, parapsychology, mental hygiene and therapeutics and psychic enfoldments with a view to ultimately awaken the human energy potential.
This is how they have practices of sitting in 28 ways, standing, bending, stretching, breathing, concentrating, quietening the mind and so forth. What unfortunately is treated as Yoga today is just some external aspects of Yoga, forgetting the attitude that goes with it.
Source: Text notes and book Yoga Sutras published by The Yoga Institute, Santacruz, Mumbai - India.