Writing over 500 books during his lifetime of 75 years, Jeong Yak-yong covered nearly all fields of knowledge in his writings, ranging from Politics and Economics to Agriculture and Castellation. However, Jeong Yak-yong was more than just a scholar. As a government official, inventor and writer, he was a reformer at heart, striving to restructure Joseon society through the philosophy of ‘Practical Learning,’ known as Silhak.

Dream of reforming Joseon Dynasty
Jeong Yak-yong was born in 1762 in today’s Namyangju, Gyeonggi province as the fourth son of an aristocrat. By the age of 4, Jeong Yak-yong was able to read the Thousand-Character Classic, and at the age of 7, he wrote poems in Chinese. From his early years, Jeong Yak-yong questioned the irrational status system and was disappointed by the scriptures of Confucianism that disregarded reality. When he was 16, Jeong Yak-yong encountered works of the Silhak philosopher Seongho Yi Ik, and was impressed by his studies that peered into the lives of the people and reality of Joseon. Determined to study a philosophy that was of practical value to life, Jeong Yak-yong entered Sungkyunkwan when he was 22 and passed the civil service examination at the age of 28.

Once he entered government service, Jeong Yak-yong had a successful career, serving various positions in the government. In 1792, he invented Geojoonggi, a traditional crane that was used for the construction of Hwaseong Fortress in Suwon. He was also appointed supervisor of the fortress’s overall construction. In 1794, Jeong Yak-yong served as a secret royal inspector in Gyeonggi province and expelled corrupt officials who abused their power against peasants. Jeong Yak-yong earned the confidence of King Jeongjo and won the hearts of peasants, but he began to face hardships soon after the death of King Jeongjo in 1800.

Scholarly achievement during exile
In 1801, Jeong Yak-yong became a victim of a persecution of Catholics known as Shinyu Bakhae and was sent into exile for 18 years. During his exile in Gangjin, Jeong Yak-yong spent time with the poor and powerless peasants and witnessed the oppression and persecution they endured. This experience had a profound effect on Jeong Yak-yong’s works. He devoted his time in exile to writing books that emphasized realizations and practical applications beneficial to the lives of peasants. Among his writings are the government’s guidebook for finance and taxation “Gyeongseyupyo” (경세유표), a book on the art of governing “Mongminsimseo” (목민심서) and a medical book on treatments for measles and smallpox “Magwahwetong” (마과회통).


Influence on future generations
In 1818, Jeong Yak-yong was freed from exile and spent the rest of his life completing his studies and compiling Silhak philosophy. He died in 1836 at the age of 75. Jeong Yak-yong’s dream of reforming Korean society was not fulfilled, but future generations looked to his philosophy for answers during troubled times and Koreans continue to revere him as a great philosopher and reformer to this day.