The Science of Raja Yoga, to which this series of lessons is devoted, teaches, as its basic principle, the Control of the Mind. It holds that the first step toward Power consists in obtaining a control of one’s own mind. It holds that the internal world must be conquered before the outer world is attacked. It holds that the “I” manifests itself in Will, and that that Will may be used to manipulate, guide, govern and direct the mind of its owner, as well as the physical world. It aims to clear away all mental rubbish, and encumbrances—to conduct a “mental house-cleaning,” as it were, and to secure a clear, clean, healthy mind. Then it proceeds to control that mind intelligently, and with effect, saving all waste-power, and by means of concentration bringing the Mind in full harmony with the Will, that it may be brought to a focus and its power greatly increased and its efficiency fully secured. Concentration and Will-power are the means by which the Yogis obtain such wonderful results, and by which they manage and direct their vigorous, healthy minds, and master the material world, acting positively upon Energy and Matter. This control extends to all planes of the Mind and the Yogis not only control the Instinctive Mind, holding in subjection its lower qualities and making use of its other parts, but they also develop and enlarge the field of their Intellect and obtain from it wonderful results. Even the Spiritual Mind is mastered, and aided in its unfoldment, and urged to pass down into the field of consciousness some of the wonderful secrets to be found within its area. By means of Raja Yoga many of the secrets of existence and Being—many of the Riddles of the Universe—are answered and solved. And by it the latent powers inherent in the constitution of Man are unfolded and brought into action. Those highly advanced in the science are believed to have obtained such a wonderful degree of power and control over the forces of the universe, that they are as gods compared with the ordinary man.