Paolo Mantegazza enjoys in Italy a reputation not only as the greatest writer in the field of philosophy, psychology, anthropology and medicine. He entered the field of the writer in the 23rd year of his life, and his first work was "Physiology of Delights." This work was met with extraordinary enthusiasm, and in the shortest possible time the work of the young scientist was translated into all European languages. This composition is not only of general interest to the entire educated public.