“‘It is, I think, worthwhile being conscious of the limits upon our powers,’ McNeill said. ‘It is worth keeping in mind that the more we win, the more we drive infections to the margins of human experience, the more we clear a path for possible catastrophic infection.’”

Garrett quotes William McNeill, a scholar at the forefront of suggesting that humanity’s relationship with microbial disease must be regarded from an ecological view. If we are in a war against disease, as many people (including Garrett) suggest, then it is a war with a balance of power, and humanity’s attempts to tip the scales in our favor will result in an escalating response from the enemy.

“Humanity’s ancient enemies are, after all, microbes. They didn’t go away just because science invented drugs, antibiotics, and vaccines […]. And they certainly won’t become extinct simply because human beings choose to ignore their existence.”

One of Garrett’s primary goals in The Coming Plague is to convey to a popular audience the scale and scope of humanity’s challenges in its war against microbial. The optimism which had previously pervaded the science and health communities had largely dissipated, but in the wider public sphere, a heady sense of optimism about medical progress still prevailed. Garrett wants people to know that, at least as far as microbial disease is concerned, optimism would be unwarranted at this point.

“From then on, Johnson stressed the need for calm in the face of epidemics, for reason, science, sound clinical training, and the ability to work with a team of diverse expertise. These were lessons passed on […] to a whole generation of infectious disease ‘cowboys.’”

Here we have one of the first mentions of the idea of a “disease cowboy.” It refers to a group of doctors who traveled worldwide doing on-field research on tropical diseases and responding to outbreaks. Such experience enabled them to attain a broad range of skills and a wide familiarity with microbial life and its effects, an experience that Garrett sees as lacking in much modern medical education.