Person1649 – 1736
Jeong Je-du (Hagok)
Scholar who systematised Yangming learning in Joseon and founded the Ganghwa school
From a Soron family, at a time when Zhu Xi orthodoxy prevailed he studied the Wang Yangming school, which held knowledge and action to be one and urged extending innate knowledge. He moved to Ganghwa in 1709 and taught disciples, and his learning passed through Yi Gwang-sa, Yi Geon-chang and others as the Ganghwa school. He left the Hagokjip.