If you want nothing, you must have it; if you want something, you must have it. So, if you want to have truth, goodness and beauty in your heart, you must stay away from falsehood, evil and ugliness. This must go through selection, identification and spiritual "street fighting" before one will withdraw and the other will take over. It reminds me that "nothing" and "have" are two abstract concepts. If there is "no grass" in the material, then there must be "crops". This is a profound metaphor. Grass is a metaphor for the false, evil and ugly in life, and crops is a metaphor for truth, goodness and beauty. When reviewing such questions, you should pay attention to turning abstraction into concreteness, so that your thinking will be broadened. If you want a person to be free from greed, you must occupy his heart with conscience; if you want a person to be free from vanity, you must occupy his heart with sincerity; if you want a person to be free from resentment, you must occupy his heart with tolerance; To make a person no longer numb, he must occupy his mind with sobriety; to make a person no longer indifferent, he must fill his heart with love, etc. The key is to grasp the big web of life and see the big from the small.