This set of essays is concerned with the explanation of large scale social change. Concentration is on the social stagnation characteristic of agrarian circumstances, the conditions for exit from that world, and the varied social orders that inhabit, sometimes precariously, the modern world community. The distinguished contributors from archaeology, anthropology, sociology, economic history and philosophy, have all been stimulated by the work of Ernest Gellner, and the essays are in dialogue with his view of our social condition.