Yul-Gok was also the first to propose the Tendong (Great Equity) System for solving the financial crisis of the Korean government. Under the Tendong System, taxes would be levied on land rather than on households and government would be required to purchase local products with tax dollars.
In addition to his active involvement, Yul-Gok was also inadvertently pulled into a serious political squabble by virtue of his philosophy. In 1575, the Korean government became mired in a political stalemate that ultimately contributed to its inability to repulse the invasion by Japan some ten years later. Two distinct factions, polarized within the Korean government, were constantly at each other's throats. These factions originally arose as a result of a personal quarrel between two men, Sim Ui-Gyom and Kim Hyo-Won. Ultimately, every official in the government had to align himself with one side or the other or risk attack by both. Since Kim's residence was in the Eastern quarter of Seoul and Sim's was in the western quarter, these two factions became known as the Easterners and the Westerners, respectively. This feuding continued long after Kim and Sim had disappeared from public life, and often took the guise of schemes designed to have members of the rival faction exiled, removed from office, or executed on false charges. These two factions were not only at odds politically but soon became philosophically opposed, with the easterners following the teachings of Yi-Hwang and the western faction following the teachings of Yul-Gok. These philosophical differences tended to drive the two factions further apart, increased the conflicts, and made the functioning of government virtually impossible.