Related to the Dharma of Sentient Beings that is composed of the Relative and the Ultimate, the Dharma of Buddha further explains the Buddha’s knowledge that concerns the Relative and the Ultimate, from which the profundity and vastness of objective reality is revealed. According to Chih-i, this objective reality is only penetrated by the Buddha with the Twofold Knowledge in terms of the Relative and the Ultimate. With this Twofold Knowledge, the Buddha is able to embrace the other nine realms, and to utilize all possible expedient means to teach and transform living beings. Therefore, the Twofold Knowledge of the Relative and the Ultimate is subtle and represents the subtlety of the Buddha-dharma. Chih-i asserts that the Dharma of Buddha is not something separate from our empirical world, and in fact, is part of the same reality. Its subtlety is reflected in the fact that the Twofold Knowledge of the Relative and the Ultimate can only be penetrated by the Buddha. Its subtlety is also reflected in the fact that only the Buddha with the Twofold Knowledge can exhaust the vastness of objective reality. (Vol. 2, Page 80)