Why is a change of civilizations? In the most general terms the answer would be: because the dominant civilization has lived her allotted time history, has exhausted its potential and went to the last phase of its life cycle. At its beginning it was a young, energetic, full of strength, contributed to better meet the growing needs of the population, high economic growth, the rise of the spiritual realm. But then these features been exhausted. Source: Ping Fu. Technological, economic, social and political arrangements, scientific and technological, educational and cultural potentials of the largely outdated, worn out, push a radical innovations. Growing gap between the excessively increased, spurred by a period of recovery needs – and increasingly limited opportunities to meet them. Can not say that this tangle of contradictions arise once for the entire life cycle of civilization.
The trajectory is more like a "camel trehgorbogo": there is usually three times the rise, after which there is a recession, crisis. First ascent – the relatively brief but high – there is the phase of formation, the rapid spread of a new civilization. Active forces of society are obsessed with the romance of creation, update the productive forces and forms of appropriation and distribution provide high rates of economic growth, improving the level and quality of life during the crisis-suffering population. But it soon becomes clear that prosperity is short-lived, largely built on the ruins the former, leaving the society, the enthusiasm of youth, whose term is limited. A period of disillusionment, the first crisis of the early stage of civilization. .