Zhou Dunyi (AD 1017–1073), formerly romanized Chou Tun-i, was a Chinese Neo-Confucian philosopher and cosmologist born in present-day Yongzhou during the Song Dynasty. He conceptualized the Neo-Confucian cosmology of the day, explaining the relationship between human conduct and universal forces. In this way, he emphasizes that humans can master their qi ("vital life energy") in order to accord with nature. He was a major influence to Zhu Xi, who was the architect of Neo-Confucianism.