Whereas the Ultimate Truth is proved to be the substance of the Lotus Sūtra, upon which all the coarse dharmas can be converged into the subtle dharma, Chih-i further argues that the Ultimate Truth can also be taken as the universal substance for all sūtras, based on his own theory of the all-embracing nature of the Ultimate Truth.

In the first aspect, Chih-i argues that the Ultimate Truth as the substance of the Lotus Sūtra actually bears different names, which are indicated in various quotations cited. The phrases quoted by Chih-i, such as “presently, the Buddha signals rays of light, wishing to reveal the doctrine of the Ultimate Truth,” “the doctrine of the Ultimate Truth of all dharmas, I have already taught you,” “to open the Buddha’s insight and knowledge,” “unsurpassed Path,” and so on, support his argument that these names refer to the Ultimate Truth. (Vol. 2, Page 429-430)