Networks are the appropriate organization for the relentless adaptation and the extreme flexibility that is required by an interconnected, global economyby changing economic demand and constantly innovating technology, and by the multiple strategies (individual, cultural, political) deployed by various actors, which create an unstable social system at an increasing level of complexity. To be sure, networks have always existed in human organization. But only now have they become the most powerful form for organizing instrumentality, rather than expressiveness. The reason is fundamentally technological. The strength of networks is their flexibility, their decentralizing capacity, their variable geometry, adapting to new tasks and demands without destroying their basic organizational rules or changing their overarching goals. Nevertheless their fundamental weakness, throughout history, has been the difficulty of co-ordination towards a common objective, toward a focused purpose, that requires concentration of resources in space and time within large organizations, like armies, bureaucracies, large factories, vertically organized corporations.