Evaluation of the foregoing studies for a new understanding of the prismatic phenomenon. The secret of the rainbow. Intimation of new possibilities of experimental research guided by the new conception of the spectrum. Part III TOWARDS A NEW COSMOLOGY XIX. THE COUNTRY IN WHICH MAN IS NOT A STRANGER (a) INTRODUCTORY NOTE From Goethe's seeing with the eye-of-the-spirit to Spiritual Imagination. Levity (Ether) as revealed to Spiritual Imagination. (b) - (e) WARMTH LIGHT SOUND LIFE The four modifications of ether. Their relation to the four elements. XX. PRO ANIMA (a) THE WELL-SPRINGS OF NATURE'S DEEDS AND SUFFERINGS The sentient (astral) forces of the cosmos as governors of the various interactions between levity and gravity. The astral aspect of the planetary system. Its reflexion in earthly substances. Beginnings of an astral conception of the human organism in modern physiology. (b) HEARING AS DEED A Goetheanistic study of acoustic phenomena and of the sense of hearing. From hearing with the ear-of-the-spirit to Spiritual Inspiration. (c) KEPLER AND THE 'MUSIC OF THE SPHERES' Goethe's view of Kepler. Kepler's third law - a revelation of the musical order of the universe. XXI. KNOW THYSELF INDEX Illustrations IN COLOUR A The relation of the electrical polarity to Levity and Gravity B The Spectrum phenomenon as conceived by Goethe C Light under the action of a transverse field-gradient MONOCHROME I. Robert Hooke's 'proof' of the non-reality of human concepts II. Leaf-metamorphosis III. Leaf-metamorphosis IV. Goethe's sketch of a cloud-formation V. A Snow-Crystal VI. A cluster of Calcite crystals VII. Various species of bacteria VIII. Various species of fresh-water algae Author's Note The author makes grateful acknowledgment of the help he has gained from other works in the wide field opened up by Rudolf Steiner, and of his debt to the friends who in various ways assisted him in preparing his manuscript. Quotations have been made from the following books by kind permission of their respective publishers: The Life of Sir William Crookes by E. E. Fournier d'Albe (Messrs. Ernest Benn Ltd.); Man the Unknown by A. Carrel (Messrs. Hamish Hamilton Ltd.); The Philosophy of Physical Science and The Nature of The Physical Worldly A.. Eddington (University Press, Cambridge); Science and the Human Temperament by E. Schrödinger (Messrs. George Allen and Unwin Ltd.); Centuries of Meditations and Poetical Works by Th. Traherne (Messrs. P. J. and A. E. Dobell). Preface In this book the reader will find expounded a method of investigating nature by means of which scientific understanding can be carried across the boundaries of the physical-material to the supersensible sources of all natural events, and thereby into the realm where is rooted the true being of man.