A series of eight lectures given in Prague on March 20-28, 1911, and a separate lecture of March 28, 1911. A book about a person, his structure and organs. About how he communicates with the outside world. It tells about the deep correspondences of the human body and space. It is shown how, studying the "external," purely physical, you can come to comprehension of the spiritual and spiritual - in man and in the Universe. Based on the data of the natural sciences and spiritual research, these considerations open the way to further study physiology as the science of a living person in the fullness of his being, a person who feels, wills and thinks.