Tzu, Sun (author) and Sawyer, Ralph D. (translator). Art of War (History & Warfare). Basic Books; February 1994 (9th edition).

As the Chinese developed a medical system designed to harmonize one with the nature and flow of the universe to attain and maintain health through knowing and following the laws of nature, the “Art of War” strategies were developed to win war through understanding and using the laws of nature to one’s advantage against an opponent.