The Plane of Matter (A) comprises the forms of Matter in its form of solids, liquids, and gases, as generally recognized by the text-books on physics. The Plane of Matter (B) comprises certain higher and more subtle forms of Matter of the existence of which modern science is but now recognizing, the phenomena of Radiant Matter, in its phases of radium, etc., belonging to the lower sub-division of this Minor Plane. The Plane of Matter (C) comprises forms of the most subtle and tenuous Matter, the existence of which is not suspected by ordinary scientists. The Plane of Ethereal Substance comprises that which science speaks of as "The Ether", a substance of extreme tenuity and elasticity, pervading all Universal Space, and acting as a medium for the transmission of waves of energy, such as light, heat, electricity, etc. This Ethereal Substance forms a connecting link between Matter (so-called) and Energy, and partakes of the nature of each. The Hermetic Teachings, however, instruct that this plane has seven sub-divisions (as have all of the Minor Planes), and that in fact there are seven ethers, instead of but one. Next above the Plane of Ethereal Substance comes the Plane of Energy (A), which comprises the ordinary forms of Energy known to science, its seven sub-planes being, respectively, Heat; Light; Magnetism; Electricity, and Attraction (including Gravitation, Cohesion, Chemical Affinity, etc.) and several other forms of energy indicated by scientific experiments but not as yet named or classified. The Plane of Energy (B) comprises seven subplanes of higher forms of energy not as yet discovered by science, but which have been called "Nature's Finer Forces" and which are called into operation in manifestations of certain forms of mental phenomena, and by which such phenomena becomes possible. The Plane of Energy (C) comprises seven sub-planes of energy so highly organized that it bears many of the characteristics of "life," but which is not recognized by the minds of men on the ordinary plane of development, being available for the use on beings of the Spiritual Plane alone--such energy is unthinkable to ordinary man, and may be considered almost as "the divine power." The beings employing the same are as "gods" compared even to the highest human types known to us. The Great Mental Plane comprises those forms of "living things" known to us in ordinary life, as well as certain other forms not so well known except to the occultist. The classification of the Seven Minor Mental Planes is more or less satisfactory and arbitrary (unless accompanied by elaborate explanations which are foreign to the purpose of this particular work), but we may as well mention them. They are as follows: 1. The Plane of Mineral Mind 2. The Plane of Elemental Mind (A) 3. The Plane of Plant Mind 4. The Plane of Elemental Mind (B) 5. The Plane of Animal Mind 6. The Plane of Elemental Mind (C) 7. The Plane of Human Mind