First published in 1939, this volume translated into English the Danish work 'Den Specielle Gymnastrikteon'. Its author, Professor Lindhard, noted the still-young field of theoretical gymnastics in comparison to its physical counterpart, with the only prior major work being that of Ling from 1800. Lindhard developed upon that work to revolutionise the 1930s interpretation of Ling's views. The author of several physiological books, Lindhard sought to explain how gymnastics was a means of developing both physical form and moral qualities. He emphasised the importance of guidance towards ethical and aesthetical gymnastics and explored the differences between men, women and children with regards to each form of exercise. This was achieved through the classification, description and contemplation of exercises such as corrective, balance and athletic exercises along with demonstrative illustrations.