In Legacies of the Sword Karl Friday writes that he entered a traditional school of martials arts (or ryuha) and explored it as an anthropologist might explore a culture. In doing so he has produced an interesting work that examines the role of the ryuha during different periods in Japanese history, and the value of studying a traditional martial art for people today. The book will give students of modern cognate arts (karate, judo, aikido, kendo etc.) an appreciation of their art's roots and history, and how they differ from the traditional 'bugei' arts that produced them. Issues such as the debate over the superiority of pattern practice and sparring as training tools, and the relationship between fighting with and without weapons are presented in an informative way and in historical context.
The book also has an extensive explanation of the principles of combat as practiced in the Kashima Shinryu (KSR)( the particular ryuha the author studied), and examples of pattern practice that illustrate these principles. The discussion of aiki was particularly valuable, and I believe most aikidoka would find it of interest.

The book is not without serious flaws, however. Very often writers on the martial arts explain the techniques and principles of their arts using the language of physics, and the result is almost uniformly a painful thing to read for anyone with any training in the subject. Sadly, Legacies of the Sword is no exception. The author is unaware that momentum and power are distinct concepts, and doesn't understand what a vector is. The principle of "Motion and Stillness as One" (one of five basic principles in KSR theory) is given a long treatment, where the argument is made that the expert can deliver more power (or momentum!) than his (presumably stationary) untrained opponent because the expert is always moving, even if imperceptibly. However, from the point of view of power delivery as explained in the text, small motion is no better than standing still. Also ignored is the fact that in order to deliver increased power, one would have to be moving along the line of attack before the attack is delivered. However, to appreciate this point, one needs to know that velocity, position, and acceleration are vectors, while 'wedges' and 'spirals' are not.

In popular discussions of martial arts one is accustomed to these sorts of errors. In fact, they are expected. Legacies of the Sword aims higher than this, as it is presented with the trappings of academic rigor (the author is a tenured member of a respected institution, the book is published by a university press, and is exhaustively footnoted), and so invites judgement according to a different standard. Unfortunately, Dr. Friday fails to meet this standard in an important way. As stated above, for the purpose of this work he attempted to act as an anthropologist, and his time in the ryuha is referred to as 'field work' on the book jacket. The problem is that study in one of these very traditional ryuha involves deep personal commitment on the part of the student to the school and its teachers. This would be difficult (maybe impossible) to do without compromising the objectivity one expects from scholarly work done at a modern western university. Dr. Friday is clearly in awe of the current headmaster of the ryuha (Seki Humitake) and his predeccessor (Kunii Zenya), repeating without substantiation (or question) claims of their undefeated records in no holds barred matches with other martial arts practitioners. We learn they won many fights, but we never get the names of who they defeated. Given that the martial arts subculture is rife with people making incredible, but always unsubstantiated claims about the superiority of their arts and abilities, more is needed before such claims can be accepted. It might be noted that there are descriptions of Kunii Zenya's defeat of a Greek orthodox exorcist in a duel of psychic energy, and of Seki Humitake frightening a bear with a 'kiate' attack, given without apparent irony.

These problems aside, I believe the book is of value and interest to most martial arts practioners. However, the problem of balancing scholarly objectivity with an insiders understanding of a martial tradition is a very serious one, and is one the author needs to address.