He learned from the Korean scholars Yi Hwang from 1563 to 1573 and Cho Shik from 1566 to 1573.
A key figure of the Neo-Confucian literati, he established the Yeongnam School and set up the Baekmaewon (백매원, 百梅園[1]), a private Confucian academy.
He was the ideological successor of Yi Hwang and Cho Shik, moral support of Namin faction (남인; 南人) and Bokin faction (북인; 北人).
There was a conflict called the Yesong Controversy (예송논쟁) then polemic of the Namin faction.
He came from the Cheongju Jeong clan (청주 정씨; 淸州 鄭氏).