Tasan`s theory of sacrificial rites(祭祀) shows his socio-political concern seeking for the rule of virtue and righteous government. He intended to motivate people into making everyday practices of the human imperatives and to revitalize effectively the traditional society of the late period of Chosun dynasty which had its basis upon li(禮, Confucian norm/order). In Mokminsimseo(『牧民心書』), Tasan formulates the cognitive process of ritual practice focussing on sacrificial rites as follows. 1) The cognition of ritual object raises intentional movement of mind/heart toward ritual objcet in cognitive process. 2) The intentionality of mind/heart entails reverence and purification in ritual pocess. Ritual practice is significant of sincerity(誠) and seriousness(敬). From the perspective of the cognitive science of religion, Tasan`s theory relates cognition with intentional pietism in cognitive process, and combines intentional pietism and reverence/purification in ritual practice. Tasan intended to regulate excessive ritual practices of the literati and restrict popular licentious cults(淫祀) in accordance with his cognitive formula. From his point of view, Confucianist`s ritual conceptions are improper/impractical and popular licentious cults are impious/enthusiastic. In order to solve these problems, He redefined Chu Hsi`s concept of seriousness as attentive concentration of convergent pietism into the concept of prudential reverence as intentional pietism. Chu Hsi`s concept of seriousness contains apophatic mysticism like Zen Buddhist Quietism(靜) via mediation, but Tasan`s concept of reverence is inclined towards kataphatic activism via contemplation.
