Chih-i believes that the Ultimate Truth is not static, but functions to
“horizontally destroy four attachments or four distortions (Ch., Ssu-tao; Skt., viparyāsacatuska) (i.e. mistaking empirical world as constancy, bliss, selfhood, and purity) of an ignorant man, and vertically refute the realization of the sages of the Tripiṭaka, Common, and Separate Teachings.” Since the four illusions of attachments of an ignorant man belong to the worldly phenomena, they are looked at from a wide-ranging view as being horizontal and profane. From this horizontal level of the profane, visually speaking, a vertical dimension arises, representing the transcendental level. Various truths that are realized by the three sages are three different levels of perception in an ascending order, rendering the dimension of height (i.e., vertical). The truth of the Two Vehicles (śrāvaka and pratyekabuddha) of the Tripiṭaka Teaching is “emptiness only” (Tan-k’ung), since these Two Vehicles can only view things as empty from the perspective of the illusory nature of things, and cannot see the provisional existence. The truth of the bodhisattva of the Common Teaching is “emptiness only and not emptiness only” (Tan-k’ung Pit-tan-k’ung), for they go one step further and see that although things are illusory and thus fundamentally empty, this illusion also indicates illusory existence. This illusory existence renders things conventionally not empty. The truth of the bodhisattva of the Separate Teaching is “not emptiness only” (Pu-tan-k’ung), and represents the view of the Middle Way. This Middle Way is free of the former two views that adhere to either emptiness or illusory existence (Ch’u-erh-pien Chung). (Vol.2, Page 12-13)