Mushin in Japanese and Wuxin in Chinese is a mental state. Zen and Daoist meditators attempt to reach this state, as well as artists and trained martial artists. They also practice this mental state during everyday activities. On page 84 of his 1979 book Zen in the Martial Arts, Joe Hyams claimed Bruce Lee read the following quote to him, attributed to the legendary Zen master Takuan Sōhō:
The mind must always be in the state of 'flowing,' for when it stops anywhere that means the flow is interrupted and it is this interruption that is injurious to the well-being of the mind. In the case of the swordsman, it means death. When the swordsman stands against his opponent, he is not to think of the opponent, nor of himself, nor of his enemy's sword movements. He just stands there with his sword which, forgetful of all technique, is ready only to follow the dictates of the subconscious. The man has effaced himself as the wielder of the sword. When he strikes, it is not the man but the sword in the hand of the man's subconscious that strikes.
However, mushin is not just a state of mind that can be achieved during combat. Many martial artists train to achieve this state of mind during kata so that a flawless execution of moves is learned and may be repeated at any other time. Once mushin is attained through the practice or study of martial arts (although it can be accomplished through other arts or practices that refine the mind and body), the objective is to then attain this same level of complete awareness in other aspects of the practitioner's life. Dr Robert Akita claims it helps him "listen to my wife and children more closely...especially when I disagree with them, [and] in my business it has helped when I am faced with difficult decisions...."