Obaku, as we have seen, taught wisdom with his fists. When the novice Rinzai came to him and asked him what was the fundamental idea of Buddhism, Obaku hit him three times with his stick. Rinzai fled and presently met the monk Daigu.

At that moment Rinzai had a Great Enlightenment.

Rinzai substituted howling for Obaku’s manual violence. He shouted meaningless syllables at his disciples; roared like a lion or bellowed like a bull. This “howling” became a regular part of Zen practice, and may be compared to the yelling of the American Shakers. Upon his deathbed Rinzai summoned his disciples round him and asked which of them felt capable of carrying on his work. Sansho volunteered to do so. “How will you tell people what was Rinzai’s teaching?” asked Rinzai. Sansho threw out his chest and roared in a manner which he thought would gratify the master. But Rinzai groaned and cried out, “To think that such a blind donkey should undertake to hand on my teaching!”

It was in the twelfth and thirteenth centuries that Zen most completely permeated Chinese thought. Upon the invasion of the Mongols[9] many Zen monks from Eastern China took refuge in Japan; the same thing happened during the Manchu invasion in the seventeenth century. But by that time Zen had a serious philosophic rival.

In the fifteenth century the philosopher Wang Yang-ming began to propagate a doctrine which, in all but names, strongly resembled the philosophic side of Zen. He taught that in each one of us is a “higher nature,” something which, borrowing a phrase from Mencius, he called “Good Knowledge.” Of this inner nature he speaks in exactly the same terms as the Zen teachers spoke of their “Buddha immanent in man’s heart.” He even uses the same kind of doggerel-verse as a medium of teaching.

Rigid Confucianists, who would not have listened to any doctrine of professedly Buddhist origin, were able through Wang Yang-ming’s tact to accept the philosophy of Zen without feeling that they were betraying the Confucian tradition. The followers of Yang-ming are to-day very numerous both in China and Japan. They cultivate introspection, but not the complete self-hypnosis of Zen.

In China, where Zen is almost forgotten, the followers of this later doctrine are not even aware of its derivation.