The term refers to a state of mind that is completely empty and void. It originates from the book Zhuangzi, in which the meaning of the term was explained by Confucius (551-479 BC) to Yan Hui (521-481 BC). Zhuangzi (369?-286 BC) believed that one’s ears and heart distinguish between oneself and others and between right and wrong, while qi (气 vital force), shapeless and empty, exists in everything and does not come into conflict with anything. Therefore, one’s mind should be empty like qi when coming into contact with external things so that one will not be different or clash with them. When one’s mind roams beyond physical things, freeing itself from the constraints and influence of other things, it maintains a state known as the “pure state of mind.”

Yan Hui said, “Could I ask what ‘the pure state of the mind’ means?” Confucius answered, “You should get totally focused. You need not listen with your ears but listen with your mind; you need not even listen with your mind but listen with qi. Listening stops at the ears, and the mind reaches only what fits it. Qi is empty and accommodates all external things. Dao gathers and presents itself in an unoccupied and peaceful mind; being unoccupied means the pure state of the mind.” (Zhuangzi)