also: かつにんけん
life-giving sword; sword that gives life
A Zen and martial arts concept: a sword can save lives rather than take them, depending on the wielder's intent. Often contrasted with 殺人刀 (setsunintō, 'killing sword').
The life-giving sword is often spoken of as a secret principle of swordsmanship.
He preached the spirit of the sword that gives life.