Yoga, an ancient but perfect science, deals with the evolution of humanity. This evolution includes all aspects of one's being, from bodily health to self realization. Yoga means union - the union of body with consciousness and consciousness with the soul. Yoga cultivates the ways of maintaining a balanced attitude in day to day life and endows skill in the performance of one's actions.
"The Energetic Anatomy of a Yogi: Healing the Emotional and Mental Body Through Yoga". Book by Paul G. Balch, Jaylee Balch, p. 23, 2013.