I will remain silent on the subject of what yoga means for India, because I cannot presume to judge something I do not know from personal experience. I can, however, say something about what it means for the West.
Our lack of direction borders on psychic anarchy. Therefore, any religious or philosophical practice amounts to a psychological discipline; in other words, it is a method of psychic hygiene.
The numerous purely physical procedures of yoga are a physiological hygiene as well, which is far superior to ordinary gymnastics or breathing exercises in that it is not merely mechanistic and scientific but, at the same time, philosophical.
In its training of parts of the body, it unites them with the whole of the mind and spirit.
When the doing of the individual is at the same time a cosmic happening, the elation of the body becomes one with the elation of the spirit, and from this there arises a living whole which no technique, however scientific, can hope to produce.
Yoga practice is unthinkable, and would also be ineffectual, without the ideas on which it is based. It works the physical and the spiritual into one another in an extraordinarily complete way.
[C.G. Jung]
Psychology and the East, p.85