Born into a prestigious family that belonged to the Disciples’ faction, Lee Jong-seong served in various government posts including the post of chief state councilor and gained the favor of King Yeongjo. He had profound knowledge of Confucianism and perceived practically various issues of his time on the basis of abundant administrative experience he had acquired from serving in various provincial government posts. Furthermore, he raised problems with the military system and forced military duty of his time, sparking several discussions on the improvement of the system and duty.
Lee Jong-seong tried to correct problems, such as a huge difference 10 duties and the increase of military taxes, caused by carrying out both the Five Camp System and regimental troops system. At first, King Yeongjo and some chief ministers who misunderstood the reality and had a lingering attachment to the systems created by the former king did not approve Lee’s reform plan, but at Lee’s repeated persuasions and requests, they agreed to execute the plan. As a result, the duplicated military system in charge of the north army commend was simplified into the army branches of studying military and artillery.
While developing the proposal to adapt the commoner cloth tax, Lee Jong-seong expressed his srance aggressively. His argument was summarized in the adaptability of the system of mounted and foot soldiers and opposition against household tax and land-cloth tax. He economically approached the adaptability of the commoner cloth tax from the perspective of finance management. The suggestion to adapt mounted and foot soldiers sought to achieve good financial condition through the improvement of finance management without making any change on the taxes imposed. In the meantime, Lee Jong-seong completely opposed a massive adaptability plan, such as a plan to impose household tax or land-cloth tax, that would change the commoner cloth tax system. As a result, he failed to present a solution except for the normed and progressive measures to tighten discipline and manage finances effectively. It was true that the problems with the commoner cloth tax could be resolved only limitedly. But, that also reflected the thoughts of the Joseon government and most Confucian scholars. Ultimately, massive adaptability plan like a plan to impose household tax failed to be adopted and Lee Jong-seong’s plans including the adjustment of the order of mounted and foot soldiers were accepted only partially. The equal service reform was a compromise measure taken to complement the reduction of tax revenues. The failure to overcome Lee Jong seong’s logic that valued the financial aspects of the commoner cloth tax was the limitation of discussions over the adaptability of the commoner cloth tax that led to equal service reform and also the limitation of the times.