[1] The philosopher Zhang Zai described the ti as "that which is never absent, that is, through all transformations.
"[1] In Neo-Confucianism, this concept is often associated with yong, which means "use" or "function."
Such function or how the yong of a thing is its activity or its response when stimulated underscores the link.
[1] Like the concepts of nei-wai (inner-outer) and ben-mo (root-branch), ti-yong is central to Chinese metaphysics.
[2] The link was adopted in order to manifest the actual meaning of the two truths and the relationship between them.