Aikido and the Dynamic Sphere
Aikido and the Dynamic Sphere is a non-fiction book about the martial art of aikido. Oscar Ratti and Adele Westbrook, husband and wife, wrote "Aikido and the Dynamic Sphere" shortly after they had achieved shodan rank in aikido, and a short stay in Japan. It is based largely on the teachings of Yasuo Ohara, founder of the New York Aikikai. The book has been praised for Ratti's many illustrations (over 1200); although it has been noted that they do not provide sufficient information for the purposes of instruction. The authors' system of numbering  techniques and attacks (rather than using the Japanese terms, which can differ between styles) has been praised for its ingenuity in unifying aikido terminology. Westbrook's text focuses heavily on the moral aspect of aikido, dividing violent encounters into four ethical levels: Another goal of the book is to explain the supposedly esoteric concept of ki in Western terms. Westbrook defines it as a "unity of mind and body - the fusion of... direction and action". The text has received criticism both for its emphasis and simplification yet it remains notable in that it was one of the first texts written  by Western aikido practitioners to address these issues. It is a standard found in most aikido libraries, remaining in print and translated into many languages.