Seeing that the correct Ultimate Truth as substance is difficult to describe, Chih-I employs three analogies to single it out. With these analogies, four cases are illustrated that correspond to the Four Teachings. This indicates that the Ultimate Truth bears different definitions in each of the Four Teachings. …

The employment of the second analogy is to single out the correct Ultimate Truth by comparing two kinds of gem. One is the crystal gem, and is named P’o-li, and another is the wishing-grant gem, and is named Ju-i (cintāmapi). Chih-i maintains that the former contains no treasure, analogizing the view of emptiness only; the latter contains treasure, analogizing the view of the Middle Way. Treasure is compared with the Middle Way that functions to save living beings. The view of mere emptiness is the view of the Two Vehicles (Śrāvaka and pratyekabuddha), who only strive for self-enlightenment. Chih-i believes that even if it is the same gem Ju-i, if it is obtained by the Two Vehicles, they would not know how to use it, which would render this gem Ju-i no function of saving living beings. However, if it is obtained by the bodhisattva, it can function to benefit all living beings. (Vol. 2, Page 411)