The Heihō Kadensho: How 'The Sword That Gives Life' Was Written

In 1632 (Kan'ei 9), Yagyū Munenori completed the family treatise on the sword, the Heihō Kadensho. He was sixty-two. The work came nearly thirty years into his tenure as the sword instructor of the Tokugawa shogunate. It is not a technical manual on the techniques of the sword themselves; it is a distinctive work that systematizes the thought, the stance, and the philosophy of the sword, and it has had a decisive influence on later Japanese martial-arts thought.

The Three Volumes

The Heihō Kadensho is in three volumes. Volume One, 'Shinrikyō,' covers basic posture and the theory of technique. Volume Two, 'Satsujintō' (Killing Sword), covers the use of the sword in actual combat and the psychology of combat. Volume Three, 'Katsuninken' (Life-Giving Sword), covers the thought of winning without drawing the sword and the application of Zen. The unifying logic across the three volumes is a three-stage doctrine of training: learn the technique in the first volume, develop combat capacity in the second, and transcend technique to reach the state of katsujinken in the third. Neither a technical manual nor a philosophical treatise in any conventional sense, the work integrates both into a single system of Japanese martial-arts thought.

The Takuan Sōhō Exchanges

The theoretical source of the katsujinken thought of the Heihō Kadensho lies in Munenori's exchanges with the Rinzai Zen monk Takuan Sōhō (1573–1646). Takuan was one of the most influential Zen figures of the early Edo period and a close friend of Munenori of the same generation. The text Takuan addressed to Munenori — the Fudōchi Shinmyōroku, the 'Record of the Marvelous Power of Immovable Wisdom' — set out the application of Zen enlightenment to the state of the swordsman, and exerted a direct influence on the katsujinken thought of the Heihō Kadensho. A new system of thought generated by the exchange between a master swordsman and a Zen monk — a rare case.

The Philosophical Stakes of Katsujinken

Katsujinken — the 'life-giving sword' — designates the sword that resolves a situation without killing the opponent. Physically it covers the technique of removing the opponent's will to fight; psychologically, the strategy of inducing his perturbation; philosophically, the stance of winning without drawing the sword. Munenori argues in the Heihō Kadensho that the master swordsman is not the one most skilled at killing but the one who has 'the option of not killing.' The thought far exceeded the combat ethics of the period and became the philosophical spine of the kendō of the twentieth century.

Influence on the Generations That Followed

The Heihō Kadensho continued to be read as the foundational text of the Yagyū Shinkage-ryū through the entire Edo period, and from the Meiji era forward it became the theoretical foundation of modern kendō. The principal currents of modern Japanese martial-arts thought — Yamaoka Tesshū's Mutō-ryū, Kanō Jigorō's judo, Ueshiba Morihei's aikidō — almost all inherit the katsujinken thought of the Heihō Kadensho. The lineage by which a master of the sword left a thought that transcends the sword can in fact be called the starting point of the philosophy of martial arts in the world today. There are several English translations, and the work is read internationally as a leadership text in business as well.

"The art of war is not the sword that kills. It is the sword that gives life."