McNeill writes in an interesting and engaging style that is sometimes difficult to find in newer scientific texts. The weight of the argument is obvious, so that the reader cannot take lightly this unusual approach to history. McNeill proposes the existence of parallel equilibria in the biological world that are historically constant. For example: “Ever since language allowed human cultural evolution to impinge upon age-old processes of biological evolution, humankind has been in a position to upset older balances of nature in quite the same way that disease upsets the natural balances within a host’s body.” Discussion of balances on macro and micro scale is original and provokes reconsideration of our place in the world. Similarly, it provides a better picture of microorganismal niches.
In regards to the role of the microorganism, Plagues and Peoples represents a perspective of the time prior to the eradication of smallpox. This perspective is slowly drifting into the slipstream of history, though it is critical to retain it in order to fully comprehend the gravity of the eradication and to realize opportunities of the future. Reading is highly recommended for all those who have not lived with the terror of the world’s greatest scourge, without the knowledge of humankind’s ability to evade the ravages of such disease.