The underlying principle of these three lessons is the Reality of the "I," in itself, over and above all Matter, Force, or Mind--positive to all of them, just as they are positive or negative to each other--and negative only to the Centre of the One--the Absolute itself. And this is the position for the Candidate or Initiate to take: "I am positive to Mind, Energy, and Matter, and control them all--I am negative only to the Absolute, which is the Centre of Being, of which Being I Am. And, as I assert my mastery over Mind, Energy, and Matter, and exercise my Will over them, so do I acknowledge my subordination to the Absolute, and gladly open my soul to the inflow of the Divine Will, and partake of its Power, Strength, and Wisdom." In the present lesson, and those immediately following it, we shall endeavor to assist the Candidate or Initiate in acquiring a mastery of the subordinate manifestations, Matter, Energy, and Mind. In order to acquire and assert this mastery, one must acquaint himself with the nature of the thing to be controlled. In our "Advanced Course" we have endeavored to explain to you the nature of the Three Great Manifestations, known as _Chitta_, or Mind-Substance; _Prana_, or Energy; and _Akasa_, or the Principle of Matter. We also explained to you that the "I" of man is superior to these three, being what is known as _Atman_ or Spirit. Matter, Energy, and Mind, as we have explained, are manifestations of the Absolute, and are relative things. The Yogi philosophy teaches that Matter is the grossest form of manifested substance, being below Energy and Mind, and consequently negative to, and subordinate to both. One stage higher than Matter, is Energy or Force, which is positive to, and has authority over, Matter (Matter being a still grosser form of substance), but which is negative to and subordinate to Mind, which is a still higher form of substance. Next in order comes the highest of the three--Mind--the finest form of substance, and which dominates both Energy and Matter, being positive to both. Mind, however is negative and subordinate to the "I," which is Spirit, and obeys the orders of the latter when firmly and intelligently given. The "I" itself is subordinate only to the Absolute--the Centre of Being--the "I" being positive and dominant over the threefold manifestation of Mind, Energy, and Matter.