Humanity today functions as a gigantic, world-encompassing system. Renowned world historian, Patrick Manning traces how this Human System evolved from Homo Sapiens' beginnings over 200,000 years ago right up to the present day. He focuses on three great shifts in the scale of social organization - the rise of syntactical language, of agricultural society, and today's newly global social discourse - and links processes of social evolution to the dynamics of biological and cultural evolution. Throughout each of these shifts, migration and social diversity have been central, and social institutions have existed in a delicate balance, serving not just their own members but undergoing regulation from society. Integrating approaches from world history, environmental studies, biological and cultural evolution, social anthropology, sociology, and evolutionary linguistics, Patrick Manning offers an unprecedented account of the evolution of humans and our complex social system and explores the crises facing that Human System today.