Written by the legendary swordsman Musashi Miyamoto, The Five Rings (c.1645) is more than just a manual on sword-fighting techniques: its Zen philosophy offers tactics and strategies as relevant to personal success today as they were to 17th-century samurai. The Five Rings speaks to every age about the essential roles of harmony and self-mastery in our lives. Of the many translations of The Five Rings, David K. Groff's translation background as a long-time resident of Japan, native-level fluency of Japanese, and an accomplished martial arts study means that he is...