Each new conquest of nature has led to the introduction of new elements into human society. Technology multiplies its products prodigiously, supported by economic theories that encourage the expansion of human wants and needs. The belief in continuous growth is part of the basic ideology of conventional social and economic thought, but little attention is paid to the character or direction of that growth. New elements are added almost at random, with little thought for their integration with other elements. Complication tends toward chaos, while complexity is highly organized.
Complexity is a characteristic of systems in which many elements are integrated to form a whole.
New parts of such systems, for example, ecosystems or higher organisms, appear only when suitable niches and adequate resources exist, so their presence makes sense and does not contribute to chaos. Complicated structures tend to be fragile, as is evident in the booms and busts of modern economies, or in the devastating impact of varying the availability of one ingredient, say, oil. In contrast, complex systems are resilient and relatively stable. They are constituted so their subunits, by systematic cooperation, preserve their integral configuration of structure and behavior and tend to restore it after nondestructive disturbances. In other words, natural systems survive all disasters short of obliteration.