By the time this book will appear, nearly six years will have elapsed since I discovered the voice of the oesophagus, and almost five since I published a preliminary account of this discovery in a book entitled The Basic Law of Vocal Utterance. This discovery, though the most comprehensive and far-reaching of any that has ever been made, not only in regard to the voice, but in regard to the better comprehension of our nature and our entire human existence, has remained as unknown to the world as if it had never been made. Yet some day, when its importance is recognized, it will take rank in the annals of the history of the human race as second to no other discovery that has influenced and shaped human thought in the proper recognition of the origin and the nature of man, spiritual as well as physical, his abilities and his limits, and his relative position, influence, and destiny in the economy of the universe.