Yi Hwang

Yi Hwang was appointed as a royal lecturer (gyeongyeon) to instruct King Myeongjong in Confucian classics. He used this position to advocate for moral governance and the application of Neo-Confucian principles in state administration.

Yi Hwang engaged in a famous philosophical correspondence with Ki Dae-seung over the nature of the Four Beginnings and Seven Emotions. This debate refined Neo-Confucian metaphysics in Korea and established Yi's distinctive dualistic interpretation of principle and material force.

Yi Hwang completed his major philosophical work, the Seonghak sipdo, a series of ten diagrams and explanations summarizing Neo-Confucian principles. This text became a foundational study guide for Korean Confucian scholars and influenced Joseon education.