Jeong Je-du moves to Ganghwa: the Ganghwa school

The Yangming scholar Jeong Je-du moved to Ganghwa Island and taught there; his disciples and descendants formed the Ganghwa school.

Yangming learning, founded by Wang Shouren of Ming, held that the mind is principle, that knowing and acting are one, and that one should extend one’s innate knowledge. It reached Joseon in the 16th century, but after Yi Hwang criticised it in his refutation of the Chuanxi lu it was shunned as heterodox, studied mainly by Soron scholars and royal kin out of favour.

In the early 18th century Jeong Je-du systematised Yangming learning in works such as the Joneon, and in 1709 moved to Ganghwa Island, where he trained disciples. Yi Gwang-sa, Yi Geung-ik (Yeollyeosil gisul), Yi Geon-chang and others formed the Ganghwa school, extending into history, the study of the Korean language and calligraphy and painting; at the end of Joseon Park Eun-sik and Jeong In-bo carried on Yangming learning.