he history of human civilization reflects a progressive increase in the complexity of large scale behaviors. Early civilizations introduced a few relatively simple large scale behaviors by use of many individuals (slaves or soldiers) performing the same repetitive task. Progressive specialization with coordination increased the complexity of large scale behaviors. The industrial revolution accelerated this process which continues till today. When the complexity of collective behaviors increases beyond that of an individual human being then hierarchical controls become ineffective. Hierarchically controled systems must yield to networked systems. Note that a system which has fixed energy and material can change its complexity profile only by transfering activities from one scale to another. Increasing complexity at one scale must be compensated by decreasing complexity at another scale. However, an increasing human population, and the addition of sources of energy during the industrial revolution (coal, oil and gas), violated these conditions, enabling the complexity to increase on all scales. As indicated on the horizontal axis, the scale of human civilization also increased.