mizu no kokoro (a mind like water)
This term, along with the one in the following section, was emphasized in the teachings of the ancient karate masters. Both refer to the mental attitude required while facing an actual opponent. Mizu no kokoro refers to the need to make the mind calm, like the surface of undisturbed water.
To carry the symbolism farther, smooth water reflects accurately the image of all objects within its range, and if the mind is kept in this state, apprehension of the opponent’s movements, both psychological and physical, will be both immediate and accurate, and one’s responses, both defensive and offensive, will be appropriate and adequate. On the other hand, if the surface of the water is disturbed, the images it reflects will be distorted, or by analogy, if the mind is preoccupied with thoughts of attack or defense, it will not apprehend the opponent’s intentions, creating an opportunity for the opponent to attack.
tsuki no kokoro (a mind like the moon)
This concept refers to the need to be constantly aware of the totality of the opponent and his movements, just as moonlight shines equally on everything within its range. With the thorough development of this attitude, the consciousness will be immediately aware of any opening in the opponent’s defenses. Clouds blocking the light of the moon are likened to nervousness or distractions which interfere with correct apprehension of the opponent’s movements and make it impossible to find an opening and to apply the proper techniques.