Today, more than one-half of the world's population lives in cities. In every corner of the world, people are moving to cities at a rapid and geometric pace. The urban migration taking place today is both historic and inevitable. Our cities represent the ultimate triumph and organizing principle of humanity. They are more than either the concrete jungle portrayed by Billy Wilder in the Lost Weekend, or the human zoo, that Desmond Morris claimed.

The great San Francisco columnist, Herb Caen, one said of cities, “that they should not be judged just by their length and width, but by the broadness of their vision and the height of their dreams.” They are, in some ways, the ultimate achievements of mankind.

Few understand them better than Monica L. Smith, a professor of anthropology and professor in the Institute of the Environment and Sustainability at the UCLA where she holds a chair in Indian Studies and serves as the director of the South Asian Archeology Laboratory in the Cotsen Institute of Archeology. She is the author, most recently of Cities: The First 6,000 Years

My conversation with Monica Smith: