Excellent book on the principles of Martial Art:

http://www.authorhouse.com/bookstore...kid~26580.aspx

I just finished it, and while many of the views contained in this book will no doubt be viewed as highly controversial to the more 'commercial' martial arts practitioners, the author makes extremely persuasive and logical arguments for his interpretations of martial arts principles. I would strongly recommend this book- it certainly made me rethink alot of my own positions with regard to martial art.