Mind like a clear mirror and still water

명경지수 (myeonggyeongjisu) means «clear mirror and still water». It is a metaphor for a clean mind free of stray thoughts, pretense and vain desires. Myeonggyeong (명경, 明鏡) is the «clear mirror» and jisu (지수, 止水) is the «still water».

The phrase comes from the Jangja (장자, Zhuangzi), chapter Deokchungbu (덕충부). It says that people do not look at their reflection in running water but in still water, and that only what is still can calm those who seek stillness.

In kumdo vocabulary, glossaries published by Korean associations stress that the character 지 (止) must not be mistaken for 之. That 止 describes a surface without the slightest movement on which the bright full moon is projected just as it is. When one's mind is calm, without even a slight ripple, the opponent's psychology and the content of the attack are projected onto oneself.

• 무념무상 (munyeommusang): a state of mental unification in which all thoughts have left the head. The glossaries describe it as the same state of mind as 명경지수. It is reached only after advanced training and is the highest level of spiritual cultivation. In it, the four afflictions (사계, sagye) no longer exist.
• 사계 (sagye, 驚懼疑惑): what damages the pyeongsangsim (평상심, the everyday mind). If any one is in the mind, it becomes confused, cannot see the opening (teum, 틈) in the opponent, and one's own shrinking creates an opening. 경 (驚) is the mental agitation caused by something unexpected. 구 (懼) is fear, which dulls mental activity and leaves hands and feet without action.