On October 5, my next book, Plagues upon the Earth: Disease and the Course of Human History, will be published by Princeton University Press. I started writing the book in 2017, and it was surreal to find myself finishing the book under lockdown while the globe was swept by a new pandemic. The book is a global history of infectious disease, spanning from our primate origins to present. (So it’s trying to capture the big picture, in the spirit of William McNeill’s classic Plagues and Peoples.) The book argues that infectious diseases are a fundamental dimension of human history. It tries to explain how human processes drive the evolution of our microbial pathogens. I hope it can put our current crisis in historical context and perhaps deepen our resolve to confront the challenges we face. Here is the introduction. Enjoy.