This book is a collection of literary works written by Yi Ik (a.k.a. Seongho, 1681-1762), who is widely regarded as a man of vision and one of the greatest political theorists in Joseon (1392-1910), and edited by his nephew Yi Byeong-hyu (1710-1776). As a Confucian scholar he stressed the importance of diligence and strict discipline, while as a political thinker he proposed a broad range of reforms according to his belief that the fundamental principle of politics should be to protect the people by securing their livelihood.