Zhou Dunyi (1017–1073) was a Song dynasty Chinese philosopher who is considered a pioneer of Neo-Confucianism. He is best known for his cosmological work, the “Taiji Tushuo” (An Explanation of the Diagram of the Supreme Ultimate), which integrates Confucian ethics with Daoist cosmology. Zhou emphasized the interplay between the principles of yin and yang, and the concept of Taiji (the Supreme Ultimate), serving as a precursor to later Neo-Confucian developments. His ideas laid the groundwork for the synthesis of Confucian, Daoist, and Buddhist thought in the subsequent intellectual tradition.