주자, or Zhu Xi, was a prominent Chinese philosopher during the Song Dynasty. He is best known for his contributions to Confucianism, particularly through his interpretation of the Four Books, which are essential texts in Confucian thought. His ideas emphasized the importance of moral self-cultivation and the role of education in achieving a virtuous life. In addition to his philosophical work, 주자 was also an influential educator and scholar. He established a comprehensive system of thought that integrated various aspects of Chinese philosophy, including Daoism and Buddhism. His teachings have had a lasting impact on East Asian culture and continue to be studied today.