It is found in Zhuangzi Fisherman, which was put forward by Zhuangzi. Starting from the thought of natural inaction, Zhuangzi and Zhuangzi's post-school opposed all false feelings that ran counter to people's "sense of life" and praised the expression of true feelings, because it was natural and spontaneous. Zhuangzi's post-school thought that only this expression of true feelings can move people's hearts: "Therefore, those who force crying are sad but not sad, those who force anger are strict but not arrogant, and those who force relatives to laugh but not harmonious. It's really sad and silent, it's really angry and arrogant. Really, I don't laugh. " Zhuangzi and Zhuangzi tried their best to maintain the unity of beauty and truth, and realized that beauty is the freedom shown by the regular movement of natural life itself. It is undoubtedly a very profound thought to grasp the essence of beauty from the unity of necessity and freedom. However, the main limitation of Zhuangzi's and Zhuangzi's post-learning lies in that their thought of natural inaction only conforms to nature blindly, and cancels the active role of human beings in understanding and transforming nature. Zhuangzi and his later school emphasized honesty, which had a great influence on the development of China literature and art. The beauty of natural freshness pursued by later generations is undoubtedly influenced by Zhuangzi School. In addition, the literary trend of thought, represented by Li Zhi, Tang Xianzu, Yuan Hongdao and others, which began to develop in the middle of the Ming Dynasty, demanded to express one's temperament directly and opposed the bondage of ethics and ethics, was undoubtedly deeply influenced by the Zhuangzi School.

Sincerity: Sincerity and undivided attention.

The general meaning of this sentence is: if you are not sincere to others, you can't impress others.