This note is featured in Boston Review’s book, Thinking in a Pandemic.

Nearly a year after the first COVID-19 cases were detected in late 2019, the toll of the coronavirus pandemic is grim. Globally, the disease has directly claimed over a million lives—more than 225,000 in the United States alone. Billions of others have been thrown into deep distress, both by the virus itself and by efforts to contain it.

In many places the numbers are only getting worse. As I write, the number of new cases has set a daily record in the United States, the daily number of hospitalizations is on its third upswing since April, and several European countries have imposed some form of a second national lockdown. Meanwhile, following successful campaigns at containment—some deeply controversial—life in many Asian countries has more or less returned to normal.

As months of protests and polarization, COVID-19 is not just a public health crisis: it is also a crisis of public reason.

But numbers do not tell the whole story. As months of protests and polarization over pandemic response have made clear, COVID-19 is not just a public health crisis: it is also a crisis of public reason. In a political climate already plagued by misinformation and historically low levels of trust in government, controversy has erupted over every facet of coronavirus research, from masks and mathematical models to data and drugs. The World Health Organization speaks of fighting not just the epidemic but an “infodemic” alongside it.

We should not mistake public controversy for expert disagreement, of course. Epidemiological consensus has converged on the importance of masks, contact tracing, mass testing, and social distancing—all key elements of responses in Asia. But the injunction to “follow the science” misrepresents the full complexity of scientific practice, especially where it intersects with political power and while it is being reshaped by the exigencies of COVID-19.

Science is more than settled theories and static facts: it is a dynamic institution. It is also not singular but plural—more than one field, more than one voice, more than one result—and its claims must be carefully reviewed, balanced, and communicated. Early inconsistencies in messaging about masks on the part of public health authorities—and the change of course prompted by democratic scrutiny of their arguments—reveal just how much public reasoning matters. “In a functioning democracy,” Sheila Jasanoff writes in her 2012 book Science and Public Reason, “there has to be a correspondence between what officials offer in the way of public justification and what is heard and respected by the citizens.”

In short, there is no royal road from expertise to action. What do we know, and how should we act? We cannot answer without public reasoning about which evidence counts, which arguments are valid, and which interventions are justified. Highly sensitive to the actions of powerful experts and ordinary citizens alike, this elaborate exercise in knowledge production, public policy, and democratic deliberation shapes the lives of billions.

There is no royal road from expertise to action. The challenge of COVID-19 has always been not just scientific but also social and political.

The essays in this volume—from epidemiologists and physicians, philosophers and historians, anthropologists and social scientists—were written on the front lines of these debates. Drawn from Boston Review’s ongoing series “Thinking in a Pandemic,” they show the public conversation about science and policy unfolding in real time. The essays are organized in three sections. The first, “Pandemic History,” sets the stage for COVID-19 by viewing pandemic science and pandemic politics in historical perspective. The second, “Pandemic Philosophy,” features an exchange with two prominent epidemiologists on the nature of evidence and the logic of intervention. And the third, “Pandemic Policy,” examines five case studies at the interface of science and society, from the health effects of the economic downturn to the implications of racial discrepancies in the workings of pulse oximeters.

The result is an essential record of public thinking about the pandemic. Together the contributors make clear that the challenge of COVID-19 has always been not just scientific but also social and political. Only by reasoning collectively about all its facets will we be able to meet it.