Man is at present a partly self-conscious soul subject to and limited by mind, life and body, who has to become an entirely self-conscious soul master of his mind, life and body. Not limited by their claims and demands, a perfect self-conscious soul would be superior to and a free possessor of its instruments. This effort of man to be master of his own being has been the sense of a large part of his past spiritual, intellectual and moral strivings.
In order to be possessor of his being with any complete reality of freedom and mastery, man must find out his highest self, the real man or highest Purusha in him, which is free and master in its own inalienable power. He must cease to be the mental, vital, physical ego; for that is always the creation, instrument and subject of mental, vital, physical Nature.
Ref: Synthesis of Yoga