The Taoist culture that only follow the law of development of things in order to achieve the harmony of man and nature. Changing all aspects of nature, everything changes follow the most basic rule is "extremes meet" this idea from the founder of Taoism - I. mean that some properties of anything to the extreme directions, these properties must cause it to turn to its own opposite, this constitutes a law of nature, so to achieve the harmony of man and nature, the development of things must master the "degree" changing the key.