Zhuangzi says: “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.”