Predictive social science does not exist. Indeed, it seems to me that it cannot ever exist, since the behaviour to be predicted reacts to and is part… - William Hardy McNeill

Ingenuity, knowledge, and organization alter but cannot cancel humanity's vulnerability to invasion by parasitic forms of life. Infectious disease which antedated the emergence of humankind will last as long as humanity itself, and will surely remain, as it has been hitherto, one of the fundamental parameters and determinants of human history.

In Korea and Japan, the Chinese example began to find fertile ground as the political and social organization or those regions developed toward civilized complexity. Buddhist monks became the principle carriers of high Chinese culture to Korea and Japan. ...The Chinese model, while of the utmost importance, never eclipsed the local differences that made Japan always and Korea sometimes so distinct from China as properly to constitute a separate civilization.

An irresistible cycle seemed to operate, repeating patterns of the ancient world where civil strife and war brought disaster... I surmised that patterned and predictable changes were in turn rooted in the very nature of civilization—the ineluctable breaker of custom and eroder of moral codes, and itself a product and expression of rapid technological and social change.