Zhou Dunyi
The (11th century CE) "Taijitu shuo" "Explanation of the Diagram of the Supreme Ultimate", written by the Zhou Dunyi (1017-1073 CE), was the cornerstone of Neo-Confucianist cosmology. His brief text synthesized Confucianist metaphysics of the "Yijing" with aspects of Daoism and Chinese Buddhism. In the "Taijitu" diagram, "wuji" is represented as a blank circle and "taiji" as a circle with a center point (world embryo) or with broken and unbroken lines (yin and yang).