Most warriors of his day, Miyamoto Musashi wrote in his last years, took their way to mean nothing more than a readiness to die. He rejected the definition. Monks, women and farmers also resolve to die when duty demands it, he argued; what belongs to the warrior alone is to prevail, over one opponent or over an army, and to train so that the skill is of use at any time and in every matter. The sword schools around him taught something else: trust in a favoured blade, in strength, and in catalogues of secret stances handed out in graded tiers. Musashi's life's work was the counter-claim that a fight is won by principle, that the principle can be learned, and that it is the same whether one man faces another or ten thousand face ten thousand.
By his own count, he fought more than sixty times between the ages of thirteen and twenty-nine and never lost. Past thirty, he looked back on that record and concluded that his victories had not come from mastering strategy: perhaps he had a natural gift, perhaps the other schools were simply weak. So he kept training, morning and evening, and only at about fifty did he feel he had reached the way itself. That is the turning point of his life as a thinker, and he describes it himself: an unbeaten record that he declined to count as knowledge.
He wrote his method down only late in life. In 1640 the Hosokawa lords of Kumamoto took him into their service, and in 1641 he set out his two-sword method in thirty-five articles for the lord, Hosokawa Tadatoshi, who died about a month after receiving them. In the tenth month of 1643, at sixty, he began the Book of Five Rings. Its central claim is that whoever truly learns to beat one opponent has learned how armies are beaten, and that this discipline, once grasped, opens onto every other art. He wrote that he no longer needed a teacher in anything. He made a point of borrowing no Buddhist or Confucian sayings and no old war chronicles to support it. The method itself taught the long sword in one hand and a grip that stays alive, since a hand that stiffens to guard has already lost. The claim about the other arts has a record in ink: about ten paintings are attributed to him, and one, a shrike on a withered branch, is an Important Cultural Property of Japan.
The surviving copies record that he handed the Book of Five Rings to his pupil Terao Magonojō a week before his death in June 1645. A single sheet of precepts in his own hand, the Dokkōdō — his title for it, meaning the way of walking alone — bears the same date, though the date is written in another hand. Its twenty-one precepts are mostly refusals — of regret, of envy, of prized possessions, of fine food — and they include a resolve to revere the Buddhas and the gods without relying on them.
Much of what people now believe about him arrived later. In 1654 his adopted son Iori, by then chief elder of the Ogasawara domain at Kokura, raised a monument whose inscription of more than 1,100 characters records a fight on an island against a swordsman called Ganryū, won with a wooden sword. A family record of 1672 tells it differently: Musashi's pupils beat the fallen man to death when he revived. The name Sasaki Kojirō attached itself to that opponent only after an Osaka kabuki play of 1737, and the famous details come from the Bukōden of 1755 and the Nitenki of 1776, two accounts of his life written more than a century after the events. The Book of Five Rings does not mention the duel. Between 1935 and 1939 Yoshikawa Eiji serialised a novel of Musashi's life in the Asahi newspaper, inventing characters and making him a seeker in whom sword and Zen became one.
Outside Japan, readers found him through the book. Victor Harris's English translation of 1974 had sold more than 120,000 copies in America by 1982, where executives read it as a key to Japanese business. His own manuscript is lost (an account of 1727 says it burned), and because only copies survive, scholars still dispute how much of the Book of Five Rings is his.