Nin

"The most important thing to remember is that the person who does dishonest or evil things is not always properly aware that what he does is bad. This is one point. Now a person of good will has the ability to repress undesirable behavior. This is 'nin', the 'nin' of ninjutsu. This idea exists, of course, in religion too, and in Zen: ninniku seishin. There is a saying, "Enduring insults and humiliation, I drop all rancor, I desire no revenge," which implies bearing no hatred and holding no grudges. Christ taught the same, when he said, "Love your enemies." This is tremendously important in our lives - indeed, I think it is the foundation: the power to show forbearance, the strength to restrain oneself. This is essential in the practice.

For example, people come to a martial arts dojo and may undergo some pain in practice, right? They are in the role of receiving attacks more and more, and then, as their taijutsu improves, their practice comes to involve dealing with attacks at a psychological level too. A person who can endure this patiently and with perseverance without losing his equilibrium will achieve a great deal. (That's why a ninja's clothes are sometimes known as "the armor of forbearance".) And the temperament of a ninja may be observed in this way. The uniform is like the kesa of the Buddhist priest, and Takamatsu-sensei used to call it "a taste of Zen". - Dr. Masaaki Hatsumi