Looked at from the point of view of other organisms, humankind therefore resembles an acute epidemic disease, whose occasional lapses into less virulent forms of behavior have never sufficed to permit any really stable, chronic relationship to establish itself.
It is risky to write a book like this. When William H. McNeill set out to analyze the manifold ways that infectious diseases have shaped world history, it was almost an entirely novel venture. Though people had been writing history for millennia, specialized works focusing on the ways that civilizations have been shaped by illness were few and far between. This seems rather strange when you consider that it was only in the twentieth century when disease reliably caused fewer casualties than enemy action during war.
Perhaps thinking about faceless enemies like viruses and bacteria simply does not come naturally to us. We personify the heavens readily enough, and do our best to appease it. But it is more difficult to personify a disease: it strikes too randomly, too mysteriously, and often too suddenly. It is, in other words, a completely amoral agent; and the thought that we are at the mercy of such an agent is painful to consider.
This tendency to leave diseases out of history books has come down to our own day. The 1918 flu pandemic is given a fraction of the coverage in standard textbooks as the First World War, even though the former caused more casualties. Curiously, however, that terrible disease did not even leave a lasting impression on those who survived it, judging by its absence in the works of the major writers of the day. It seems that memory of disease fades fast, at least most of the time. The 1968 Hong Kong flu killed 100,000 Americans that year (which would translate to 160,000 today), and yet neither of my parents remembers it.
This is why I think this book was a risky venture: there was not much precedent for successful books written about the history of diseases. Further, since there was not much in the way of prior research, much of this book must perforce consist of speculation using the spotty records that existed. While this does leave the historian open to the criticism of making unfounded claims, as McNeill himself says, such speculations can usefully precede a more thorough inquiry, since at least it gives researchers an orientation in the form of theories to test. Indeed, in my opinion, speculative works have just as important a role as careful research in the advancement of knowledge.
McNeill most certainly cannot be accused of a lack of ambition. He had completed an enormous amount of research to write his seminal book on world history, The Rise of the West; and this book has an equally catholic orientation. He begins with the emergence of our species and ends with the twentieth century, examining every inhabited continent (though admittedly not in equal detail). The result is a tantalizing view of how the long arc of history has been bent and broken by creatures lighter than a dust mite.
Some obvious patterns emerge. The rise of agriculture and cities created population densities capable of supporting endemic diseases, unknown to hunter-gatherers. Living near large masses of domesticated animals contributed much to our disease regimes; and the lack of such animals was decisive in the New World, leaving indigenous populations vulnerable to the invading Europeans’ microbes. Another recurring pattern is that of equilibrium and disturbance. Whenever a new disease breaks in upon a virgin population, the results are disastrous. But eventually stasis is achieved, and population begins to rebound.
One of McNeill’s most interesting claims is that the great population growth that began in the 18th century was partly a result of a new disease regime. By that time, fast overland and sea travel had exposed most major urban centers to common diseases from around the world, thus rendering them less vulnerable to new shocks. I was also surprised to learn that it was only the rise of modern sanitation and medicine—in the mid 19th century—that allowed city populations to be self-sustaining. Before this, cities were population sinks because of endemic diseases, and required constant replenishment from the countryside in order to maintain their numbers.
As I hope you can see, almost fifty years after publication, this book still puts forward a compelling view of world history. And I think it is a view that we still have trouble digesting, since it challenges our basic sense of self-determination. Perhaps one small benefit of the current crisis will be an increased general curiosity about how we still are, and have always been, mired in the invisible web of the microscopic world.
View all my reviews