 In the Buddhist tradition, the relation of reality and its manifestation has been characterized in many ways, e.g., emptiness (kong 空) and form (saek 色), prajñā (chihye 智慧) and skillful means (pangp’yŏn 方便), and principle (i 理) and phenomena (sa 事), as well as Buddha-nature (pulsŏng 佛性) and sentient beings (chungsaeng 衆生). But its most important application, seen in Korean Buddhism (and also Korean Neo-Confucianism), is that of Essence (體) and Function (用) where Essence refers to the innermost, fundamental dimension of the human mind, for example, the Buddha-mind as the pure, innate mind in and of itself, and Function refers to the manifested activity of such a mind in the world. In this context, Essence refers to the underlying nature of the mind, and Function to the expressed state, feeling or behavior of the person; and that state, feeling or behavior may belong to an ordinary unenlightened person (Muller 1995).