The intellectual foundation of Razan's life's work was based on early studies with Fujiwara Seika (1561–1619), the first Japanese scholar who is known for a close study of Confucius and the Confucian commentators. This "kuge" noble had become a Buddhist priest; but Seika's dissatisfaction with the philosophy and doctrines of Buddhism led him to a study of Confucianism. In due course, Seika drew other similarly motivated scholars to join him in studies which were greatly influenced by the work of Chinese Neo-Confucianist Zhu Xi, a Sung-dynasty savant. Zhu Xi and Seika emphasized the role of the individual as a functionary of a society which naturally settles into a certain hierarchical form. He separated people into four distinct classes: samurai (ruling class), farmers, artisans and merchants.