Nor does the thought or concept stop here. There is the relation of the Individual Intelligence we call MAN to the Universal Intelligence we call GOD, which as related to Nature is "In All, Through All, Over All, and Above All." Not an "Absentee God," but Illuminant within and without revealing itself in what we call Love and Law. Here "in brief" I rest the case and proceed to the evidence. INTRODUCTION In "A Study of Man, and the Way of Health," first published twenty-one years ago, as a general outline for my classes of Medical Students, to enable them to grasp the real problem of life, and to emphasize the Study of Man, as basic in the Study of Medicine, the following epitome was placed in the Preface. "The cosmic form in which all things are created and in which all things exist is a Universal Duality. Involution and Evolution express the two-fold process of the One Law of Development, corresponding to the two planes of being, the Subjective and the Objective. Consciousness is the central Fact of Being. Experience is the only method of knowing. Therefore, to Know, is to Become. The Modulus of Nature, that is, the Pattern, after which she everywhere builds, and the _Method_ to which she continually conforms is an Ideal, or Archetypical Man. The Perfect Man is the anthropomorphic God. A living, potential Christ in every human soul. Two natures meet on the human plane, and focalize in man. These are the Animal Ego and the Higher Self. The one, an inheritance from lower life. The other, an overshadowing from the next higher plane. The Animal Principle is Selfishness. The Divine Principle is Altruism. However defective in other respects human nature may be, all human endeavor must finally be measured by the principle of Altruism and must stand or fall by the measure in which it inspires and uplifts Humanity. The highest tribunal is the criterion of Truth, and the test of truth is by its use and beneficence. 'BY THEIR WORK YE MAY KNOW THEM.' Superstition is not Religion; Speculation is not Philosophy; Materialism is not Science; but true religion, true philosophy and true science are ever the handmaids of Truth, and will at last be found in perfect harmony." After more than twenty years of continuous and careful study since the foregoing was written, I must still confirm and emphasize these basic propositions to-day. The attempt is herein made to apply them more particularly to the study of Psychology. To add to what was then discerned and designated as "the Modulus of Nature," an exact and comprehensive Theorem of Psychology.