Korean History › Late Joseon › Silhak (Practical Learning)
Jeong Yak-yong (Dasan)
1762–1836· Person· Culture, religion & science
Well documentedSolid records, physical evidence or scientific consensus.
A late-Joseon scholar-official, engineer and prolific writer, widely seen as the greatest synthesizer of Silhak (Practical Learning).
See it on the Korean History map →What happened
Jeong Yak-yong (정약용), pen name Dasan, passed the civil exam in 1789 and became a favorite of King Jeongjo. He drafted plans and lifting devices for Hwaseong Fortress and a pontoon bridge for royal crossings of the Han. His family's Catholic ties ruined him after Jeongjo died: in 1801 one brother was executed and he was exiled to Gangjin for 18 years. There he wrote some 500 volumes, including Mongmin simseo, a manual for honest local magistrates.
Why it matters
His writings on land, law, administration and technology are the fullest Joseon-era reform program, and he remains Korea's model of the upright official.
Think of it like
Mongmin simseo reads like a property manager's operations manual: collect fairly, stop the skimming, look after the tenants.
Legacy and how we know
His collected works (Yeoyudang jeonseo), his restored exile retreat Dasan Chodang in Gangjin, and court records; Mongmin simseo is still read by Korean civil servants.
Still debated
Whether he quietly remained Catholic after renouncing the faith is debated.
Connections (3)
▸Jeong Yak-yong (Dasan) was the leading scholar of Silhak (Practical Learning)Well documented
The connection
Jeong Yak-yong pulled together earlier Silhak strands: Yu Hyeong-won's and Yi Ik's land reform ideas and Northern Learning's openness to technology. In exile he wrote complete blueprints for government, law and local administration, the fullest statement of the movement.
When and how
Mostly at Gangjin, South Jeolla, during his exile of 1801–1818, then at his home near Seoul until 1836.
How we know
His roughly 500 volumes survive, collected as Yeoyudang jeonseo (printed 1934–38); he names Yi Ik as a key influence.
Debates and open questions
Calling him the culmination of Silhak assumes Silhak was a school, which some historians question.
▸Jeong Yak-yong (Dasan) designed cranes for Hwaseong Fortress (Suwon)Well documented
The connection
In 1792 Jeongjo asked Jeong to plan the new fortress. Using a Chinese-Jesuit machine manual (Qiqi tushuo) from the royal library, he drafted the layout and designed a pulley crane (geojunggi) and other lifting devices that cut the labor and cost of raising heavy stone.
When and how
Seoul, 1792 planning; construction at Suwon, 1794–1796.
How we know
His essays on fortress design and the crane in his collected works, and the crane drawings in the Hwaseong seongyeok uigwe.
Debates and open questions
How much of the final design was his, versus the officials and master builders involved, and how heavily his crane was actually used, are uncertain.
▸Jeong Yak-yong (Dasan) was exiled during Catholic persecutions in JoseonWell documented
The connection
Jeong met Catholic books in his youth through his brother-in-law Yi Seung-hun and family friend Yi Byeok, then renounced the faith. In the 1801 persecution his brother Jeong Yak-jong was executed, brother Yak-jeon was exiled to Heuksan Island, and he was exiled too, ending up in Gangjin for 18 years, where he wrote most of his works.
When and how
1801: trials in Seoul, then exile, from late 1801 at Gangjin, South Jeolla; released 1818.
How we know
The 1801 interrogation records and Jeong's own letters and writings from exile.
Debates and open questions
Whether his renunciation was sincere is debated; some Catholic accounts claim he returned to the faith before his death.