This term means choosing to be useless to realize the preservation of life. Originating in Zhuangzi, choosing to appear useless is a way advocated by Zhuangzi for preserving one's life. He said that very able people are often required to shoulder many responsibilities, which will result in greater difficulties and dangers harmful to their physical and mental health. Zhuangzi concluded that only by giving up the desire to advance or become useful, showing instead how useless one is, can one avoid the perils of the human world and therefore preserve one's life 去书内