Everything has its "that," everything has its "this." From the point of view of "that" you cannot see it, but through understanding you can know it. So I say, "that" comes out of "this" and "this" depends on "that" - which is to say that "this" and "that" give birth to each other. But where there is birth there must be death; where there is death there must be birth. Where there is acceptability there must be unacceptability; where there is unacceptability there must be acceptability. Where there is recognition of right there must be recognition of wrong; where there is recognition of wrong there must be recognition of right. Therefore, the sage does not proceed in such a way, but illuminates all in the light of Heaven. He, too, recognizes a "this," but a "this" which is also "that," a "that" which is also "this." His "that" has both a right and a wrong in it; his "this" too has both a right and a wrong in it. So, in fact, does he still have a "this" and "that"? Or does he in fact no longer have a "this" and "that"? A state in which "this" and "that" no longer find their opposites is called the hinge of the Way. When the hinge is fitted into the socket, it can respond endlessly. Its right then is a single endlessness and its wrong too is a single endlessness. So, I say, the best thing to use is clarity.

The Complete Works of Chuang Tzu