Chih-i argues that although each realm is differentiated from other realms as having different definitions of the Ten Suchnesses, together, they constitute the Ultimate Truth that consists of the relative and ultimate reality. In other words, the relative and the ultimate are coexistent as a polar concept and are contained within each other in terms of soteriological significance. On the one hand, without the relative of the nine realms, the ultimate of the Buddha-realm cannot be substantiated, and without the ultimate, the relative does not have any validity, two of which form a polar concept existing interdependently. On the other hand, if the relative does not contain the ultimate, then the attainment of Buddhahood would not be possible; if the ultimate does not contain the relative, then the Buddha would not undertake his task of teaching and saving beings. Only if the ultimate is already contained in relative as the cause for Buddhahood, can the attainment of Buddhahood as the effect be possible, whereby all beings in the nine realms are grounded to be able to eventually enter the Buddha-realm; only if the relative is contained in the ultimate, can the Buddha’s endless soteriological activities of saving beings be realistic. (Vol. 2, Page 80)