This is a collection of writings by Jeong Do-jeon (penname: Sambong, 1342-1398), a neo-Confucian scholar who greatly contributed to King Taejo’s foundation of the Joseon Dynasty. Jeong is also credited with establishing neo-Confucianism as the sole ruling philosophy of the newly established dynasty. He, along with Kwon Geun, oversaw substantial reforms of Joseon’s culture, civilization, and institutions. The book provides valuable information on the founding philosophy of Joseon and is an excellent source material for Korean studies. Jeong Mun-hyeong, his great-grandson, republished this collection in six books in 1465 (the 11th year of King Sejo’s reign), this item being the first book (Vol. 1 and 2) of the collection.