Thick black theory was a philosophical school and theory in ancient China, also known as the "thick black way". Its founder was Li Zongwu, who mainly elaborated on the core ideas and theories of "thick black theory". "Thick Black School" advocated the use of morality as the basis and black school as a means to achieve the purpose of standing, developing and strengthening in society by cultivating personal morality and mastering skills. Its core idea was that "virtue is thick and power is strong, but it causes illness and death". " Black learning " referred to the psychology and sociology founded by Li Zongwu, which advocated the purpose of changing society and oneself by analyzing human nature and grasping social laws. Li Zongwu's study of thick black had a profound impact on Chinese history. His work, Thick Black Study, had also become one of the classics in Chinese history. However, as time went on, thick black studies were gradually questioned and criticized as a theory that was misunderstood and abused.