While witnessing the chaos of Choson's order after the war and fundamentally realizing the ills of the prefectural system, Yoon Hyu(尹鑴) and Kim Manyoung(金萬英), as Choson's Confucians in the 17th century, looked forward to reform by the feudalism as a means to achieve three generations of the rules. Yoon engraved The Book of Changes(周易) as a basis, arguing that the prefectural system failed to pass on the essence of the feudalism, and that in order to reverse its ills, it was necessary to strengthen local administration and achieve the situation of "running the state together under the Heaven" through the Kindly Way. While Kim pointed out that the cause of most contemporary problems lies in the unreasonable prefectural system, and proposed reforms around taxation, the official system, personnel selection, the military system, and other aspects. The theory of feudalism and prefectural system embodies, so to speak, the profound reflection of Choson's Confucians on reality during the late Ming and early Qing dynasties and, at the same time, implies the vitality and the intrinsic logic of East Asian traditional thought when facing modernization trend.