My home library has a shelf of books on the history of plagues and epidemics. William H. McNeill’s Plagues and Peoples provides a fascinating epidemiological timeline, from the dawn of civilization through the 20th century. What this history shows is that microbes have had more effect on the course of human history than all the leaders, tyrants, invasions, political theories, and ‘isms’ combined. Pandemics have always been with us and will always be with us. We do not float above nature. We are nature -- like all other living things an exquisite assemblage of molecules and cells. Many of these...