Neo-Confucian scholar whose Cheonmyeong Doseol set off the Four-Seven Debate; pen name Chuman
| Life | 1509 ~ 1561 |
| Era | 조선 중기 |
| Clan | 경주 정씨 |
Jeong Ji-un (1509-1561), courtesy name Jeongi and pen name Chuman, was born in Goyang, Gyeonggi. Bright from childhood, he studied under Kim Jeong-guk and Kim An-guk and later learned the Simgyeong and Yihak Gyemong from Yi Hwang. He lost his father at 20 and his mother at 23, mourned them with filial devotion, and kept three years of mourning in his heart when his teacher Kim Jeong-guk died. He declined recommendations to office.
To clarify the principle of creation he wrote the Cheonmyeong Doseol and revised it in 1553 following Yi Hwang's opinion; the first diagram is called the Old Diagram (Cheonmyeong Gudo) and the revised one the New Diagram (Cheonmyeong Sindo), both surviving. The discussion of this treatise between Yi Hwang and Gi Dae-seung developed into the Four-Seven Debate. His disciples included Jeong Ji-rim, Jeong Sik and Kim Eun-hwi.
In 1561 he fell ill while touring Mount Cheonma at the arrangement of his disciple An Hong and died at Gangguo in Pungdeok on the way home. His Cheonmyeong Doseol was printed from woodblocks in 1640.
The Cheonmyeong Doseol explains in pictures and words how the principle of heaven appears in people and things. Jeong Ji-un wrote it, sought Yi Hwang's opinion and revised it in 1553. In the process Yi Hwang and Gi Dae-seung exchanged long letters on the relation between the Four Beginnings and Seven Emotions, the Four-Seven Debate that deepened Joseon Neo-Confucianism.
The Encyclopedia of Korean Culture says it is generally regarded as the first such work attempted in Korea, though its relation in time to Kim In-hu's diagram is also discussed. That judgment is the author's scholarly view, so look at the wider academic discussion too.
Goyang has the tomb of Jeong Ji-un, designated as a local heritage site, and he is said to have been enshrined at Munbong Seowon. The present state of the academy and whether rites continue could not be confirmed. The Wikipedia article carries a notice that its sources are unclear, so cross-check with other materials.
His tomb (Goyang City Local Heritage No. 11) is in Goyang, and he was enshrined at Munbong Seowon there.
His father is given as Jeong In-pil; Wikipedia writes the name 仁弼 while the Encyclopedia of Korean Culture writes 寅弼. Descendants could not be confirmed.