Through continual exercise of this kind only, sound becomes the right medium for the revelation of the spirit and the soul. Of course, it implies the strictest self-discipline, but it leads to a high goal. When these practices are undertaken in connection with those that deal with the sounds of Nature, the soul develops a new sense of hearing. It is enabled to receive demonstrations from the spiritual world which do not find their expression in outward sounds apprehensible by the physical ear. The perception of the "inner word" awakens. Gradually truths from the spiritual world reveal themselves to the student, and he hears them expressed in a spiritual way.[8] [8] Only to him, who listens disinterestedly, comes the ability to perceive really from within, silently, and without emotion arising from personal opinion or personal taste,--to such only can the Great Souls, who are known in Occultism as the Masters speak. As long as our opinions and feelings are in a state of vehement opposition to the communications from the Masters, They remain silent. All high truths are attained through such "inner encouragement," and what we hear from the lips of a genuine occult teacher has been experienced in this manner. In so saying it must not be supposed that it is useless to acquaint oneself with the writings on occult science, before one can actually gain this inner encouragement. On the contrary, the reading of such writings, and the listening to eminent teachers of occult lore, are themselves the means of attaining a personal knowledge. Every sentence of the esoteric wisdom which one hears is adapted to direct the senses to that point which must be attained before the soul can experience a real advance. To the practice of all that has been indicated, must be added an ardent study of what the occult teacher gives out to the world. In all occult schools such a study belongs to the probationary period, and he who would employ other methods will attain no goal if he omits the instructions of the occult teacher, for inasmuch as these instructions proceed from an actual "inner word," an actual "encouragement," they possess in themselves a spiritual vitality. They are not mere words; they are living powers; and while you follow the words of an occultist, while you read a book which comes from a genuine inner experience, powers are at work in your soul which make you clairvoyant, just as natural forces have created out of living matter your eyes and ears. V ENLIGHTENMENT.