A human being has been continuouly pursued to predict the unforeseen future. As a part of ways to prepare unforeseen future, many oriental scholars have researched and developed various ways to predict people' destiny. Through personal birth information (year, month, day, time) and SaengGeokjehwa(생극제화) in EumyangOhaeong(음양오행), Sajumyunglihak(사주명리학) has become a one of popular methods to predict future. Old and new types of myunglihak(명리학) has been in use depending on selecting what criteria in order to raise predictive value accurately.
The study tries to review 1) main contents of old theory in 『LiHurjoong mingshu』, 『Nagrogjasammyungsosigbuju』, 『Okjosineungjinkungju』 2) major arguments of new theory, 3) the fundamental method of Gyukookyongsin(격국용신) selection and development of Gyukook(격국) in Japyeonghuk(자평학) among the book of 『Yeonhaejapyeong』, 『Sammyeongtonghae』, 『Myeongrijeonjong』. Especially, Jangnam's unique theory, Jungdongsul(정동설), Byeongyaksul(병약설), Gaedoosul(개두설) are minutely described. As to Sagilsin(사길신), Sahyungsin(사흉신) of Soonyong(순용), Yeokyong(역용) in 『Japyeongjinjeon』, Gyukook(격국), yongsin(용신), and yongsinjungbeop(용신정법) are analyzed from a current perspective.
Moreover, in the part of 『Jeokcheonsucheonmi』, the analysis and operation of Sajonggyuk(사종격), and the comparative analysis of jonggyuksaju(종격사주) based on a modern perspective are described.
The underlying theme of Myunglihak is to forecast one's future accurately. This study aims to improve predictive value and create a new method of Ganmyung. After all, I hope this study will contribute to future work on Myunglihak.