This book explores Neo-Confucianism and its relationship to politics by examining the life and work of the two iconic figures of the Joseon dynasty Yi Hwang (1501-1570, Toegye) and Yi I (1536-1584, Yulgok). Neo-Confucianism became state orthodoxy in 1392, and remained in place for over five centuries until the end of the dynasty in 1910, thereby shaping the Korea of today. Toegye and Yulgok founded the two main schools of Josean Neo-Confucianism, which became the most dominant schools of thought in Korean history. In shedding new light on the important relationship between these two iconic figures, Hyoungchan Kim offers an important new examination of Korea today, which will be essential to those interested in the philosophy and history of Korea.