I encourage everyone here who likes reading to check out this book.
I have no connection to the author &c, but am merely a satisfied owner of the book.
The author is a longtime student of Chito-ryu karate, and also a student of iaido, for 38 and 20 years respectively as of publishing the Second Edition. He published this book first in 1993, and a second edition in 2011. As far as I am aware, the link above is the only place you can get this book ... and he appears to be clearing out the remaining stock. You can check out the "Recent Posts" links to sample his writing style and level of analysis.
This book was recommended to me (and everyone else in our dojo) by my longtime Sensei, who speaks highly of it as a good reference for a lot of concepts and terminology relating to karate and other martial arts. While the book is generally written with all martial arts in mind, rather than specifically for karate, the author's personal experiences lead to a strong "karate flavour".