The decline of civilization is a common idea that the life of civilizations would follow a cycle of life: gestation, birth, growth, climax, and decline. Examples in support of this thesis are often:
It is possible to classify the causes of the decline of civilizations into two broad categories: endogenous causes, generated by civilization itself (political and social crises, structural crises, financial crises, wars, etc.), and exogenous causes, that is to say, external causes such as the appearance of epidemics, diseases or natural events (climate, volcanoes …).
Joseph Tainter, an American researcher at the University of Berkeley, demonstrates in his book The Collapse of Complex Societies that civilizations with a certain degree of complexity can only decline, not least because all efforts to maintain their stability lead to an increase in complexity more and more unmanageable. Joseph Tainter highlights the growing complexity resulting in diminishing returns. It also explains how energy and complexity are embedded in a reciprocal causal relationship that can lead to societal collapse (see next section).
In some cases, a natural event (tsunami, earthquake, large fire, global warming, etc.) appears as an immediate cause of the decline of a civilization. In other cases, it is the loss of an essential resource to a society that can lead to its decline. Among other things, we note the importance of the energy resource. The various studies on the evolution of civilizations highlight a strong correlation between the presence of abundant and cheap energy and the degree of complexity of a society. For example, a company that has become highly complex by taking advantage of abundant energy goes into a context of energy crisis that faces a double constraint threatening its sustainability: the growing number of problems to manage (increasing complexity) doubled with decreasing capacity to solve these problems (less energy available). Among other things, this notion of limited resources is the basis of theories on the risks of the collapse of industrial civilization.
If we consider the different peoples who occupied North America before the European explorers as a single civilization, we can say that it disappeared at the beginning of the sixteenth century, on the one hand, of course, by the massacres perpetrated on a large scale by the colonists, but also by contagious diseases of the Old World, against which the immune system of the natives was not prepared.