K’ai-san Hsien-i (Opening the three and revealing the one) is the function related to the Subtlety of Objects. This is spoken of in terms of the teaching and principle. Chih-i points out that in the Lotus Sūtra, the truth of emptiness held in the three teachings are identified with the Ultimate Truth. The Buddha made it clear that the underlying principle as the Ultimate Truth is embedded in these three teachings, since the ultimate goal of them is to lead beings to attain the One Vehicle of Buddhahood. (Vol. 2, Page 445)