the cosmos—on achieving oneness with nature. Zen was anti-scholastic and anti-rational. Its adherents sought sudden intuitive insight as a result of extreme physical discipline and mental concentration, rather than wisdom through book learning or through logical thought. As a means of training in Zen, the master would pose a seemingly trivial or irrational problem, such as the nature of the sound caused by a clapping motion made with only one hand instead of with two. The student would meditate upon this problem for days, but any answer describing the nature of sound or the reasons for the absence of sound would not be tolerated by the master. The train of meditation started by this problem was intended to result in a flash of sudden enlightenment regarding the nature of the Buddha, the oneness of the universe, or other problems equally profound.
The anti-scholasticism, the mental discipline—still more the strict physical discipline of the adherents of Zen, which kept their lives very close to nature—all appealed to the warrior caste, with its predilection for the Spartan life. Zen rapidly became the philosophy of the military men of feudal Japan, giving them a philosophical foundation on which to base their lives. With their support, it rose to a position of wide influence and great prestige. Zen contributed much to the development of a toughness of inner fiber and a strength of character which typified the warrior of feudal Japan; and Zen has continued to play its role in recent years by giving spiritual strength and firmness to many members of the officer caste.