The highest term of evolution is the spirit in which knowledge, love and action, the threefold dharma of humanity, find their fulfilment and end. This is the atman in the anandakosha, and it is by communion and identity of this individual self with the universal self which is God that man will become entirely pure, entirely strong, entirely wise and entirely blissful, and the evolution will be fulfilled. The conquest of the body and the vital self by the purification of the emotions and the clarification of the intellect was the principal work of the past. The purification has been done by morality and religion, the clarification by science and philosophy, art, literature and social and political life being the chief media in which these uplifting forces have worked. The conquest of the emotions and the intellect by the spirit is the work of the future.
Yoga is the means by which that conquest becomes possible.
In Yoga the whole past progress of humanity, a progress which it holds on a very uncertain lease, is rapidly summed up, confirmed and made an inalienable possession. The body is conquered, not imperfectly as by the ordinary civilised man, but entirely. The vital part is purified and made the instrument of the higher emotional and intellectual self in its relations with the outer world. The ideas which go outward are replaced by the ideas which move within, the baser qualities are worked out of the system and replaced by those which are higher, the lower emotions are crowded out by the nobler. Finally all ideas and emotions are stilled and by the perfect awakening of the intuitive reason which places mind in communion with spirit the whole man is ultimately placed at the service of the Infinite.