Book of Five Rings by Miyamoto Musashi

"Go Rin No Sho (The Book of Five Rings) is a text on kenjutsu and the martial arts in general, written by Miyamoto Musashi circa 1645. It is considered a classic treatise on military strategy, much like Sun Tzu's The Art of War. There have been various translations made over the years, and it enjoys an audience considerably broader than only that of martial artists: for instance, some business leaders find its discussion of conflict and taking the advantage to be relevant to their work. The modern-day Hyōhō Niten Ichi-ryū employs it as a manual of technique and philosophy.

Musashi establishes a "no-nonsense" theme throughout the text. For instance, he repeatedly remarks that technical flourishes are excessive, and contrasts worrying about such things with the principle that all technique is simply a method of cutting down one's opponent. He also continually makes the point that the understandings expressed in the book are important for combat on any scale, whether a one-on-one duel or a massive battle. Descriptions of principles are often followed by admonitions to "investigate this thoroughly" through practice, rather than try to learn by merely reading.

Musashi describes and advocates a two-sword style: that is, wielding both katana and wakizashi, contrary to the more traditional method of wielding the katana two-handed. However, he only explicitly describes wielding two swords in a section on fighting against many adversaries. The stories of his many duels do not seem to reference Musashi himself wielding two swords, although as mostly oral traditions their details may be rather inaccurate. Some suggest that Musashi's meaning was not so much wielding two swords 'simultaneously', but rather acquiring the proficiency to (singly) wield either sword in either hand as the need arose."

... according to Wikipedia (http://en.wikipedia.org/wiki/The_Book_of_Five_Rings)

Too be honest I'm not 100% sure where this version came from. I believe that there is a version at Project Gutenberg (http://www.gutenberg.org), but not sure if this is it. I know that at some stage I borrowed a copy of it of a friend and copied it out by hand, although I have the original text around somewhere .. I didn't note the translator from Japanese. I'll have adjusted the spelling - honour is honour not honor etc. I'm trying to track a down another version from somewhere to blend the two of them, creating a version that takes the different interpretations and adds my thoughts to it a bit more - for now it is a cut and paste job as I get content on this page :-)