This term means a reversal to an original and opposite state. By extension, it also refers to the way changes occur in a relationship of opposites. In this sense, the term has two different meanings: one is that a thing’s attribute or state will under certain circumstances always transform itself to its opposite; the other is that a thing reverts to its original or fundamental state or attribute. The concept of reversal to an opposite is an expression of the ancient Chinese understanding of the rules governing the way things change.