It is an established and accepted occult fact that the soul works through the mechanism of the threefold personality in stimulating the three worlds of human evolution -- the mental, the emotional and etheric/physical planes of consciousness. It is said that the aspirant to discipleship really needs to know only two things: the constitution of man and the next step ahead. In this book the way the human constitution actually functions in its component parts is made abundantly clear. It is an accepted goal for the aspirant that he learns to make of his personality equipment an instrument for the soul to use.