In this thesis, based on Yulgok's theory to study "Daehak", it was examined how scholars of Horn and Nakron developed the theory to study "Daehak" regarding Bunyeom and Pyeonnyeom in the context of the history of ideas. The scholars of Horon and Nakron developed Yulgok's theory to study "Daehak" arguing that one could fully recover a saint's mind only after studying Seongeui(誠意, sincerity) to get rid of Aknyeom(惡念, an evil intention), Jeongsim(正心, an upright heart) to control Bunyeom, and Susin(修身, moral training) to control study and Pyeonnyeom. Yet, as scholars of Nakron criticized Horon scholars' argument considering the study of Jeongsim to control Bunyeom as Jeongsi(靜時, calm time), the controversy over the theory to study "Daehak" developed. The scholars of Horon generally insisted that because the method of Seongchal(省察, introspection) suggested in "Jeongsimjang(正心章, Chapter of Upright Heart)" of "Daehak" was not going into Dongsi(動時, dynamic time) and fathoming with Saryeo(思慮, consideration), but releasing it at the very moment of catching the indication of four troubles relevant to Bunyeom, the study on Jeongsim in "Daehak" should be the study of Jeongsi(靜時, calm time) for Jonyang(存養, developing good nature) of the main part of mind. On the other hand, the scholars of Nakron mostly contended that because Sim(心, mind) discussed in "Jeongsimjang" of "Daehak" referred to the whole mind and was not limited to Mibalsim(未發心, mind not manifested yet) of Jeongsi(靜時, calm time), the study on Jeongsim should include Dongjeong(動靜, movements). Yulgok once commented on Lee Yeon-pyeong(李延平)'s study on Mi-bal-che-in(未發體 認) in the same context of the study methods of release at the very moment of light reflection(輕輕照管·輕輕放退). In this respect, study on Jeongsim to control Bunyeom can be separated and belong to the study on Mibal of Jeongsi(靜時, calm time) as the scholars of Horon did. On the other hand, from the aspect that regarding the study on Jeongsim, Yulgok discussed both Jonyang(存養, developing good nature) and Seongchal(省察, introspection) with Mibal(未發, not manifested) and Yibal(已發, already manifested) together, it seems to have no problem to think of Jeongsim as the study including Dongjeong(動靜, movements). There were no different opinions between the scholars of Horon and those of Nakron regarding that there was study of Jeongsi(靜時, calm time) in "Daehak", too. However, while the scholars of Horon usually understood the study of Jeongsim in "Daehak" itself as the study of Mibal in "Jungyong", some scholars of Nakron thought that even though the study of Jeongsim of "Daehak" corresponded to Dongsi(動時, dynamic time), it included the study on Mibal because of the logic of Che-yong-il-won(體用一源). It can be said that the discussion over the study of Jeongsim to control Bunyeom and the study of Susin to control Pyeonnyeom were not limited to the proposal of the methodology to just control Bunyeom and Pyeonnyeom, but developed into the understanding of "Daehak" and "Jungyong" as one system of study.