The Book of Five Rings (五輪書, Go Rin No Sho) is a text on kenjutsu and the martial arts in general, written by the swordsman Miyamoto Musashi (宮本 武蔵) circa I've read this book many times over the last 40 years. It's worth reading over again.
"Some believe that it is only great power that can hold evil in check. But that is not what I've found. I found it is the small things. Every day deeds by ordinary folk that keeps the darkness at bay." - Gandalf the Grey/White quote from Lord of The Rings by J.R.R. Tolkien. More