Upset by one or another of these disturbing and disruptive forces, civilized populations have panicked and retreated from their collectiveness toward more localized, more fragmented, less social and more individual life patterns. Such a retreat rounds out the later phases of a cycle of civilization--the phases of decline and final dissolution. Civilizations perish in the first instance because of internal contradictions and conflicts, the struggle to grab, monopolize, and keep wealth, status, power. They perish because of the division of the nucleus and its associates and dependencies between those who work for a living, those who have an unearned income and those parasites who scrounge for a living. They perish because of the hard class and caste lines that grow out of economic contradictions; because of the development of a social pyramid, layer above layer, until the summit is reached where there is standing room for only a few. Competent, talented persons may rise from level to level in this pyramid. A political and social bureaucracy develops which feeds at the public trough. Then comes a bitter struggle to get both feet in the trough and keep them there side by side with an equally determined effort to exclude outsiders and other intruders. An army of volunteers and novices is converted into a military establishment which becomes a state within the state, extending its control until it makes policy, selects top leaderships and carries on its internal feuds and wars of succession dividing the defense forces and using them for partisan purposes. Overhead costs rise; deficits in the public treasury grow; so does public debt. Inflation follows, and the debasement of the currency. Levies are made on private wealth for public purposes. There is expropriation of the property of political enemies. Espionage, secret agents, the growth of informers become part of the society, along with the use of assassination as a political weapon, the increase of violence and crime, and eventually, a flight from the cities. This tragic enumeration only skims the surface of the many and various aspects of a situation that reaches its breaking point in civil war, famine, pestilence and eventually in depopulation. Social dissolution is accelerated by provincial revolts against central authority; by survival struggle between the empires which were coordinated and consolidated into the civilization; by revolt in the subordinate and dependent segments of the civilization; by rivalry and conflict between racial, cultural and political sub-groups forced into the civilization, held there by coercion, policed by armed force and taking the first opportunity to win political independence and self determination. While the momentum for expansion lasted, the civilization grew in wealth and power. When it waned, disintegration set in. Changelessness seems to be impossible in a social group. A civilization either expands or withers, builds up or falls to pieces.