How did Zen finally emerge, after all the centuries and the convolutions? As Hakuin's descendants taught Zen, a monk entering the monastery was assigned a koan chosen by the master. He was expected to meditate on this koan until his _kensho_, his first glimmer of satori, which might require two to three years. After this a new phase of study began. The monk was then expected to work his way through a program of koans, requiring as much as a decade more, after which he might meditate on his own, in seclusion, for a time longer.20 The master worked with monks individually (a practice reputedly left over from the time when Chinese-speaking masters had to communicate in writing) via a face-to-face interview (_senzen_) reminiscent of a Marine Corps drill instructor harassing a recruit. The monk would bow to the master, seat himself, and submit his attempt at resolution of the koan. The master might either acknowledge his insight, give him some oblique guidance, or simply greet him with stony silence and ring for the next recruit--signifying an unsatisfactory answer. Hakuin made his disciples meditate; he made them struggle through koan after koan; he made monastic discipline as rigorous as possible; and he taught that it is not enough merely to be interested in yourself and your own enlightenment. But he insisted that if you follow all his teachings, if you meditate the right way and work through increasingly difficult koans, you too can find the enlightenment he found, an enlightenment that expressed itself in an enormous physical vitality. _Even though I am past seventy now my vitality is ten times as great as it was when I was thirty or forty. My mind and body are strong and I never have the feeling that I absolutely must lie down to rest. Should I want to I find no difficulty in refraining from sleep for two, three, or even seven days, without suffering any decline in my mental powers. I am surrounded by three- to five-hundred demanding students, and even though I lecture on the scriptures or on the collections of the Masters' sayings for thirty to fifty days in a row, it does not exhaust me.21 _ Hakuin was a prolific writer and always aware of his audience. For his lay followers, he wrote in simple Japanese and related his teachings to the needs and limitations of secular life. For his monk disciples he wrote in a more scholarly style. And finally, we have many long elegant letters composed for various dignitaries of government and the aristocracy. He also was an artist of note, producing some of the most powerful Zen- style paintings of any Japanese. Like his writings, these works are vigorous, impulsive, and dynamic. He seems to have been an inspiration for many later Zen artists, including Sengai (1750-1837) and the Zen poet Ryokan (1758-1831).22