Tao Te Ching Enlightenment The world knows that beauty is beauty, and evil has been;We all know that what is good is good, and what is not good is good. Therefore, there is no symbiosis, difficulty and ease are mutually compatible, the length is dwarfed, the high and the low are inclined to each other, the sound is harmonious, the front and back are followed, and the constant is also. It is to do what the saint does not do, and to teach without words. All things are done without beginning, born without being, for the sake of not being ashamed, and succeeding and dwelling. The husband is not going. 
Lao Tzu's narrative in this passage speaks of the concepts of good and evil, as well as beauty and ugliness. Different from figurative things, such as stones in life, tables, chairs and benches. The existence of the concept of the world depends on the human mind. There is no specific criterion for judging good and evil, beauty and ugliness. As the saying goes, "in the eyes of the lover", so this point is actually a value judgment. In fact, the generation of value judgments is also relative. In Lao Tzu's view, when people know what is beautiful and ugly, the concept of good will also appear. Humans make value judgments based on cognition.
And many things in life are interdependent and opposed to each other, as Lao Tzu said, long and short, high and low, sound (sound: beautiful sound;Sound: ordinary sound), before and after, etc. In the history of human development, whenever something new appears, there will be good and bad sides. It's just a difference embodied by the different objects of value. In the text, "existence and non-existence are mutually generated" illustrates that existence and non-existence are mutually transformative. It's like an individual's life from nothing to nothing, and then from something to nothing. The Himalayas used to be rivers and disappeared into mountains, but who can guarantee that they will not become oceans again. On the other hand, "difficulty and ease are compatible" reflects that different things have different values and concepts for different objects. This is actually a kind of dialectical thinking.
It means that in order to talk and do things, we must always think about the opposite side of things, so that we can handle things more properly. It can also mean not to speak too much, just like the contradictory story, insisting that the spear is the sharpest spear and the shield is the strongest shield. Too extreme to consider the other side of the spear and shield.
Everything has its good and bad, and only by looking at it comprehensively can we not be confused.