The teaching of the main text is summed up in a few sentences at the beginning: all that is seen, heard, felt, understood, is hon-shin. This word means literally heart-essence, explained here with consciousness-only texts. When we see a mountain, we see hon-shin in the form of a mountain; when we hear a bird singing, we hear hon-shin in the form of bird-song. When we lie down on a straw mat, we lie down on hon-shin in the form of a mat.
Then Torei shows how Zen completes the Confucianism, which was the official doctrine for samurai at the time. He points out (as did some Confucians) that it is easy to intone phrases like filial piety, loyalty, and human-heartedness. But most people cannot in fact control their desires and fears, so they fall into evil ways, not stopping at murder of relatives. Zen will enable them to control themselves and follow their principles. If the heart is uncontrolled, then though they look, they do not see, though they listen, they do not hear, and though they eat, they do not taste. One with an uncontrolled heart is like a novice archer who has learned the technique of shooting, but not how to focus on a target. He shoots at random and is entirely destructive. Again he is like a gardener who likes flowers and fruit but does not cultivate the root, because he does not know the connection. The true noble Confucianism can be fully practiced when the heart-essence has been attained.
In the same cheerfully eclectic Japanese manner he praises the Way of the Gods (Shinto), Emperor-worship, and the shrine cults in general (though not quite all; some elements of Left Tantrism had crept in). Without realization of the heart-essence, these may drop away into formal rituals.
The traditional history of Zen was important because Zen was being revived in Japan by Hakuin. The Rinzai branch of it had almost died out. All forms of Buddhism had to be authenticated by showing an unbroken transmission from the Buddha-teaching of India, the Holy Land, through the patriarch-transmission of China. Zen teachers were well aware that some of the most revered traditions do not appear in early records. See for instance the koan-story of the Buddha’s twirling a flower before the assembly, as set out in No. 65 of the Warrior Koans (see page 64). Nevertheless they maintained the forms and recited them regularly.
He explains at length how warriors have practiced Zen at times of crisis, and their example inspired others. If some practice hard, all will go well. In the end, the instruction to a samurai and to a Buddhist nun is the same: practice meditation in rest and in action, till the Buddha-heart stands clear in you. It is urgent repetition of truth, with a view to dispelling illusion by sheer insistence. The method, practiced all over the Far East, consists of repeating central truths, with slight variations or even in the original words, again and again. It is effective when the words are repeated verbally with great force, or even when read slowly with strong conviction. The main Buddhist terms are in sonorous Chinese monosyllables; a samurai would have had to read them aloud, slowly, in order to understand them, as there is no redundancy in the written characters. (They correspond to the internationally recognized mathematical symbols, 2, 8, =, %, and so on, which have no one accepted pronunciation, and have to be read carefully.) But reading a translation into an alphabetic script full of redundancies, the eye tends to race over the text, which soon appears merely repetitious and boring. This could be avoided by tape recording the main text with slow enunciation, and then listening to it with concentration.
There are other forms of Kufu; vivid visualization of some of the striking illustrations given in the main text could be one of them.
There is a brief note near the end which echoes one of Hakuin’s own writings called The Koan (riddle) of Illness: these have been given as directions for when one is ill. But when he is not ill, let him remember not to waste his time either.