The human life alternates between the great, external macrocosm and the invisible inner microcosm. Steiner discusses the various paths of self-development that lead across these two thresholds and to the transformation of human soul-forces into spiritual organs of perception. A brief synopsis: The world behind the tapestry of sensory perceptions; human life between macrocosm and microcosm. The planets and their connection with our sleeping and waking life; consciousness soul, mind soul, and sentient soul. The inner path of the mystic; the cycle of the year; the ability to see through matter; the "greater guardian of the threshold." The nature and development of human soul faculties; the "lesser guardian of the threshold"; the sun at midnight; the results of "sins of omission." The Egyptian mysteries of Osiris and Isis; initiation experiences; the Rosicrucian path; mystics of the Middle Ages. Initiation in the "northern mysteries"; the necessity of suppressing the ego; conscious assent into the macrocosm and the higher worlds; the world of archetypal images. The four spheres of the higher worlds; the threshold of the spirit world; forces for developing clairvoyant consciousness in the world of archetypal images. The macrocosm mirrored in the human being; the nervous system as an inner solar system; the image of purified blood and the conquest of our lower nature in the symbol of the Rose Cross. Spiritual organs of perception and the strengthening powers of sleep; the thinking of the heart; the ego viewed from twelve perspectives. Reading the akashic record; the transition from intellect to heart thinking; four-dimensional space; intellectual questions have no meaning in relation to conditions before the intellect itself existed. Human and planetary evolution; adaptation to the different states of Earth's existence; the breathing process should not be influenced directly unless knowledge has become prayer.