In Wonhyo' s 『Ijangŭi』, the two obscurations(二障) refer to the hindrances of passion and delusion(煩惱障) and the hindrance of worldly knowledge (所知障). The hindrances of passion and delusion(煩惱障) troubles the mind and body of yujeong and causes them to leave jukjeong. The hindrance of worldly knowledge(所知障) is an impediment in which hok like the attachment to things blocks the nature of wisdom and disables it to reach at hyungwan. The hindrances of passion and delusion(煩惱障) relates to the attachment to self(我執) suggesting that never changing self exists; and the hindrance of worldly knowledge(所知障) concerns the attachment to things(法執) suggesting that objective reality exists. In 『Ijangŭi』, Wonhyo discussed chesong and types of kleśa(煩惱) while categorizing them into the exoteric level (顯了門) and the esoteric level(隱密門). Observing such typology, researchers have considered that Ijangŭi is an attempt to confluence and communicate the mind only and Tathāagatagarbha(如來藏) thoughts. However, I believe that the focal point of 『Ijangŭi』 lies in the mind only. Therefore, I aim to clarify the genuine intention of Wonhyo inherent in his fundamental thoughts by approaching the hindrance of worldly knowledge (所知障) presented in the exoteric level(顯了門) from the mind only perspective. In the mind only, the existence mode of self and the world is explained by the mind. The self and the world that we think of are not the real objects but the mind only. In the mind only science, the mind is categorized into eight components: 5th consciousness, the consciousness, Manas, and the Ālayavij na(我賴耶識). The 5 th consciousness is the one that functions when dealing with the fifth kyung that is parallel to the fifth kun of perception organs; the consciousness functions to perceive the consciousness that is taken at this point by synthesizing it. It is because that the perception is not made possible by perception organs only; but it is made possible when consciousness activities arise for objects. Manas is a self consciousness that takes place when the sixth consciousness perceive the objects. When the consciousness comes to objectify things by thinking them differently, Manas gets to remain fixed self continuity stable. Manas takes as soyeon the Ālayavij na(我賴耶識), which forms self and the world when it comes cross relations while bearing the traces of the precedent karma as a seed. In the preface of 『Ijangŭi』, Wonhyo clarified that the aim of writing Ijangŭi is to get rid of the attachment to self(我執) and the attachment to things (法執) and further to obtain the emptiness to self(我空) and emptiness of phenomenon(法空), this being sought to reach Nirvana and bodhi. The hindrances of passion and delusion(煩惱障) that causes the attachment to self(我執) has a close relationship with the consciousness and Manas. It is because the hindrances of passion and delusion(煩惱障) holds self consciousness that Manas is my consciousness for the world perceived by the consciousness though sensory organs, which leads to brings about tough kleśa(煩惱) such as gyun, man, tam, jin, chi. The hindrance of worldly knowledge(所知障) that causes the attachment to things is more delicate kleśa(煩惱); and it goes along with Manas and the Ālayavijñna(我賴耶識). It is because despite people being born with wisdom by which he/she is able to know things clearly, they make it differentiated between my things and others and they form self and the world drawing upon karma. In 『Ijangŭi』, Wonhyo communicated the argument of Hobub(護法) that the attachment to things(法執) is not found in the Ālayavij na(我賴耶識) with that of Anheo(安慧) arguing the opposite. He thought that the ideas of Hobub(護法) and Anheo(安慧) both make sense; while the hindrances of passion and delusion(煩惱障) has something in common with the seventh vij āna and also relates to the eighth vijñāna, the hindrance of worldly knowledge(所知障) speaks the same language with all the eight consciousness. That the hindrance of worldly knowledge(所知障) has something in common with all the eight consciousness indicates to accept that there are delicate kleśa(煩惱) in Ālayavijñna(我賴耶識). This argument is closer to the standpoint of the mind-only that the Ālayavij na (我賴耶識) is jinmanghwahap than Tathāagatagarbha (如來藏) Wonhyo is a monk who practiced muaehang as well as a thinker who brings immortal jinyeomun and ever changing sangmyulmun into a conclusion of the whole heart. Wonhyo s representative thought of the single mind has a close parallel to the standpoint of the mind only that sees the Ālayavij na (我賴耶識) in terms of jinmanghwahap. That the hindrance of worldly knowledge (所知障), the delicate kleśa(煩惱), has something in common with the entire eight consciousness means that there is no separate chin that goes beyond mang, but rather knowing mang as such indicates chin. In other words, there does not exist separately neither chulsegan - leaving the world - nor pureness - leaving abhorrence. Rather, seeing discrimination of wisdom(依 他起性) as such is to overcome parikalpitasvabhāva(遍計所執性) and to regain non-discriminative wisdom(圓成實性). Wonhyo opened a new path for Korean Mahayana Buddhism. Wonhyo having practiced muaehaeng as a monk, his thoughts are based upon bulii thoughts that consider as a unity, each pair of: yum and jung, segan and chulsegan, jinyeo and sangmul, jungsang and Buddha. In particular, the following evidences all present clearly that Wonhyo focuses more on the mind only than on Tathāagatagarbha(如來藏): In 『Ijangŭi』, most of pages being spared for the exoteric level(顯了門) than the esoteric level(隱密門); placing eight types of delusions for a category of kleśa(煩惱) by locating at the forefront the hindrance of worldly knowledge(所知障), this being coined in the mind only; interpreting chesung of the two obscurations(二障) as the fifth, which is a categorization method of the mind only.