The two truths are non-dual. Reality is an integrated unity. Chih-i illustrates this by quoting the metaphor of the drunk man in the Mahāparinirvāṇa Sūtra who perceives the sun as “spinning around.” A sober man correctly perceives that there is only one sun, one reality, and that the spinning of the sun as perceived by the drunk man is caused by his deluded and drunken state. A deluded person thus has mistaken perceptions of the way things are, but an enlightened person perceives reality as it is and can see that the deluded person’s perceptions are a mistaken interpretation of reality.

Reality is best described as “one,” integrated, and interpenetrating, but as Chih-i points out,

if one becomes attached to this reality, words concerning reality become empty words. Since a mistaken verbal view arises, it is called “crude.”[T. 33, 705a24-25]

Even the verbal expression “one truth” must be understood as an ultimately inadequate expression of reality. If one is attached to the concept of “one truth,” it is necessary to go one step further and deny the possibility of adequate verbal expression. In Chih-i’s words, which presage the Ch’an / Zen proclamation to not rely on written words, one must “destroy [the notion of one truth] by saying ‘no truth’.”

The one truth is [actually] no [truth]; all truth is at rest. Each and every [truth] is [ultimately] inexpressible …
It is necessary to say “no truth” for the sake of those who have not fulfilled attainment, and in their attachments give rise to delusion. For those who have real attainment, there is [a positive truth]; for those [lost] in vain speculation, there is none. [T. 33, 705a28-29; b15-16]

Once again we find the tension in Chih-i’s philosophy between the strong assertion that reality and truth are ultimately beyond language and rational concepts, and the recognition of the undeniable need to express the Buddha Dharma, “truth,” and “reality” with words and concepts which are more valid than others. This is the task undertaken by Chih-i in his lectures and writings.