tudies in North Korea, which defined Yulgok’s Liqi theory(理氣論) as the idealism of Liqi-yiwon(理氣二元), were ... idealism of Liqi-yiwon(理氣二元) including materialistic elements by compromising Hwadam's Qi-ilwon theory(氣一元 ... viewpoint of materialism. In addition, categorizing Liqi-museonhuseol(理氣無先後說) into materialism and