This paper explores ways of accommodating jigiò¸Ñ¨ (lit. ultimate energy) within Korean philosophical discourse. I will argue that jigi was conceived on the basis of a Koreanized notion of giÑ¨, which has its origin in the Chinese term qiÑ¨ but bears considerable difference from the Neo-Confucian framework of liqi×âÑ¨ metaphysics. The following three points will be examined. First, as a new coinage referring to the ultimate reality of DonghakÔÔùÊ (lit. Eastern Learning), jigi straightforwardly represented an awareness of Donghak while other terms like sangje, cheonju, and hanallim were used as general nouns for ultimate reality, adopted in different situations according to broader contexts. Second, jigi was not worked out through the medium of a Neo-Confucian worldview: even though Donghak came into being in a Confucian state, JoseonðÈàØ Korea, Donghak¡¯s proposal of seeing gi as ultimate reality should not be reduced to a branch of liqi metaphysics but rather properly be appreciated as a new worldview. Finally, a comparison of gi and qi in contemporary usage in both the Korean and Chinese languages shows that the concept of jigi experienced as mutual resonance is deeply rooted in the Korean language.