Aiki (martial arts principle) and its practice is often kept within a particular individual or two from a family/school lineage. Culturally, and due to certain necessities of the time period, the aiki knowledge was usually a very well guarded secret and rarely disclosed. The oldest book to have historically discuss aiki was the 1899 Budo Hiketsu-Aiki no Jutsu. On the subject of aiki it was written: The Textbook of Jujutsu (Jujutsu Kyoju-sho Ryu no Maki) from 1913 wrote: Aiki (martial arts principle) Aiki from a Japanese budo term, at its most basic is a principle that allows a conditioned practitioner to negate or redirect
Collaboration: Japanese Agents and Local Elites in Wartime China "Chinese Historical Review" describes the book as a "finely researched" and "subtly nuanced" study. He says that "what is remarkable is that Professor Brook has uncovered from both the Chinese and Japanese sides archival and memoir literature of a quality that allows him to present case studies that illuminate the ambiguities and complexities of collaboration, not to mention the essential mechanics of how it was sought and arranged." The reviewer concludes that "this work is not only a major contribution to the history of the [Second] Sino-Japanese War and that of modern China; it also makes an invaluable addition to