One of the most important things needed in kyudo practice is to achieve the state called "no-mind". In Daisetz T.Suzuki's book "Zen and Japanese Culture" this state is explained in the chapter devoted to swordsmanship. Despite the fact that the author only briefly mentions archery, his explanation of zen's role in swordsmanship is valid for kyudo as well, and for many other martial arts for that matter. So, here's an excerpt from this chapter:
"Some may ask: How can the sword which implements the will to kill work out its function by itself without the willer's directive behind it? What originality, what creative work, can an inanimate mechanical tool be made to carry out all by itself? When a tool performs whatever function it is made to perform, can we say it has achieved something original?
The point is: When the sword is in the hands of a technicial-swordsman skilled in its use, it is no more than an instrument with no mind of its own. What it does is done mechanically, and there is no myouyuu* discernible in it. But when the sword is held by the swordsman whose spiritual attainment is such that he holds it as though not holding it, it is identified with the man himself, it acquires a soul, it moves with all the subtleties which have been imbedded in him as a swordsman. The man emptied of all thoughts, all emotions originating from fear, all sense of insecurity, all desire to win, is not conscious of using the sword; both man and sword turn into instruments in the hands, as it were, of the unconscious, and it is this unconscious that achieves wonders of creativity. It is here that swordplay becomes an art.
As the sword is not separated from the man, ot os an extension of his arms and accordingly a part of his body. Furthermore, the body and the mind are not separated, as they are in the case of intellectualization. The mind and the body move in perfect unison, with no interference from intellect or emotion. Even the distinction of subject and object is annihilated. The opponent's movements are not perceived as such and therefore the subject, so called, acts instinctually in response to what is presented to him. There is no deliberation on his part as to how to react. His unconscious automatically takes care of the whole situation.
The swordsman calls this unconscious "the mind that is no-mind" (mushin no shin), or "the mind that knows no stopping" (tomaranu kokoro), or "the mind abandoned and yet not abandoned" (sutete sutenu kokoro), or "the everyday mind" (heijou-shin). The secret of swordsmanship consists in attaining to this state of mentality – or, we may call it, spirituality, because it is beyond the realm of psychological phenomenalism. Yagyuu Tajima no kami Munenori (1571-1646), one of the greatest swordsmen in the history of the art, taught Tokagawa Iyemitsu (1604-1651), the third Shougun of the Tokagawa regime. This Tajima no kami studied Zen under Takuan (1573-1645) and incorporated much of the Zen teaching into his treatise on swordsmanship. He says that the mind that is no mind is the last stage in the art of swordplay. "To be of no-mind" (mushin) means the "everyday mind" (heijou-shin), and when this is attained, everything goes on well. In the beginning, one naturally endeavors to do his best in handling the sword, as in learning any other art. The technique has to be mastered. But as soon as his mind is fixed on anything, for instance if he desires to do well, or to display his skill, or to excel others, or if he is too anxiously bent on mastering his art, he is sure to commit more mistakes than are actually necessary. Why? Because his self-consciousness or ego-consciousness is too conspicuously present over the entire range of his attention – which fact interferes with a free display of whatever proficiency he has so far acquired or is going to acquire. He must get rid of this obtruding self- or ego-consciousness and apply himself to the work to be done as if nothing particular were taking place at the moment. When things are performed in a state of "no-mind" (mushin) or "no-thought" (munen), which means the absence of all modes of self- or ego-consciousness, the actor is perfectly free from inhibitions and feels nothing thwarting his line of behaviour. If he is shooting, he just takes out his bow, puts an arrow to it, stretches the string, fixes his eyes on the target, and when he judges the adjustment to be right he lets the arrow go. He has no feeling of doing anything specifically good or bad, important or trivial; it is as if he hears a sound, turns around, and finds a bird in the court. This is one's "everyday mind" (heijou-shin). The swordsman is thus advised to retain this state of mentality even when he is engaged in a deadly combat. He forgets the seriousness of his situation. He has no thought of life and death. His is an "immovable mind" (fudou-shin). The fudou-shin is like the moon reflected in the stream. The waters are in motion all the time, but the moon retains its serenity. The mind moves in response to the ten thousand situations but remains ever the same. The art culminates here. All the scheming of the intellect has been quieted, and no artifice finds room for its demonstration.
Yagyuu Tajima no kami quotes in this connection words of Hou Koji (P'ang the Lay Disciple): "It is like the wooden horse facing the flowers or birds." This is the state of mushin (no-mind). The wooden horse has no mind, no sentiency. Even when it confronts the flowers, or hears a bird singing, it is utterly unmoved. Man is altogehter different from the wooden horse. He has sentiency and is subject to all kinds of stimulation. But when he finds himself moved in one way or another, he is commited. Even though engaged in the struggle for life, the swordsman must not be disturbed, he must remain master of himself, must be like the wooden horse, insensible to all the environmental vicissitured…
…Here are a few short quotations from Yagyuu's triple treatise on the sword:
The mind unmoved is emptiness; when moved it works the mysterious.
Emptiness is one-mind-ness, one-mind-ness is no-mind-ness, and it is no-mind-ness that achieves wonders…
…Give up thinking as though not giving it up. Observe the technique as though not observing.
Have nothing left in your mind, keep it thoroughly cleansed of its contents, and then the mirror will reflect the images in their isness.
See first with the mind, then with the eyes, and finally with the body and limbs.
Don't be afraid of blinking when the eye unexpectedly confronts an object. It is a natural thing.
I am moving all day and not moving at all. I am like the moon underneath the waves that ever go on rolling and rocking.
Let yourself go with the disease, be with it, keep company with it: this is the way to get rid of it.
You are said to have mastered the art when the technique works through your body and limbs as if independent of your conscious mind.
Turn yourself into a doll made of wood: it has no ego, it thinks nothing; and let the body and limbs work themselves out in accordance with the discipline they have undergone. This is the way to win."
* "Myouyuu (miao-yung in Chinese) or daiyuu (ta-yung), or simply myou, is a certain artistic quality perceivable not only in works of art but in anything in Nature or life. The sword in the hands of the swordsman attains this quality when it is not a mere display of technical skill patiently learned under the tutorship of a good master, for myou is something original and creative growing out of one's own unconscious. The hands may move according to the technique given out to every student, but there is a certain spontaneity and personal creativity when the technique, conceptualized and universalized, is handled by the master hand…"from the book "Zen and Japanese Culture" by Daisetz T.Suzuki (1993, Mythos, Bollingen series LXIV, Princeton University Press)