What is Bai Juyi's famous theory of poetry creation?

Bai Juyi's thought combines Confucianism, Buddhism and Taoism. Guided by the Confucian thought that "poverty is the only way to protect yourself, and achievement is the best way to help the world", it acts independently. His ambition of "benefiting both the people and the people" is mainly to implement Confucian benevolent policies, but it also includes the theory of Huang Lao, the technique of treating Xiao and the method of applying for Korea. His mind of "being alone" absorbed the concepts of contentment, uniformity and freedom of Laozi and Zhuangzi and the Buddhist thought of "liberation". The second song "Song of Awakening" said: "I heard that there is a way out for Futu teaching." Seeking peace of mind, going all out, uncomfortable. When trusted by the emperor, he spoke out politically and dared to do things, so his poetry creation actively reflected the sufferings of people's livelihood and served to make up for current events. When he loses trust and can't do anything, he asks to be dismissed from his post or to be an idle official. Instead of avoiding disaster, he amused himself with poetry, wine, Zen and traveling, and his poetry creation mainly expressed his personal feelings. No matter whether he is rich or poor, he can't live without poetry.