A Book of Five Rings: The Classic Guide to Strategy by Miyamoto Musashi

'When you attain the Way of strategy, there will not be one thing you cannot see.'
- Miyamoto Musashi, Book of Five Rings

Shortly before his death in 1645, the undefeated swordsman Miyamoto Musashi retreated to a cave to live as a hermit. There he wrote five scrolls describing the "true principles" required for victory in the martial arts and on the battlefield. Instead of relying on religion or theory, Musashi based his writings on his own experience, observation, and reason.