Unbound: How Eight Technologies Made Us Human and Brought Our World to the Brink

by Richard L. Currier

In time, the societies of these regions began to invent and adopt new technologies of interaction—the sailing ships, wheeled vehicles, domesticated horses, and systems of writing that made it possible for people and communities to interact over time and space. As a result, the market towns, religious centers, and communities of wealthy and powerful families gradually grew into urban centers that began to dominate the smaller and less powerful neighboring towns. Eventually, as the technologies of interaction grew in sophistication and effectiveness, these expanding urban centers knitted the settlements of entire regions into a network of allied communities, and in time these communities became the seeds of the urban civilizations that sprouted, one by one, in the cradles of civilization scattered across the globe.