
Li was a scientist of political intrigue. He wrote: "When you conceal your will from others, that is Thick. When you impose your will on others, that is Black (Dark)." Thick Black Theory describes the ruthless, hypocritical means men use to obtain and hold power: "thick faces" (shamelessness), "black heart" (cruelty), according to author's view of history. It went through several printings before being banned in China as subversive.