In the age of coronavirus, Americans are gripped by tales of the Spanish flu. Lessons from that pandemic crowd the op-ed pages. Books about the contagion climb the best-seller lists. Lawmakers in Washington spread the comparison like slaps on the back.

On one level, it's a healthy impulse: Historical perspective helps us appreciate the scale of today’s disaster and the extraordinary response it demands. Yet history—particularly the glib, unexamined kind—can lead us astray as often as it illuminates.

The lessons of 1918, once you start to survey the claims, are so open to interpretation as to seem nearly meaningless. One writer argues strict lockdowns worked best in 1918; another claims the key to success was leaving some schools open. One authority refers to 1918 as a "cataclysmic" crisis; another stresses the economic fallout was "surprisingly mild." Subtle shifts in point of view can completely change the takeaway.

So what is history for? Yes, it can reinforce one’s pet theories. But there’s another way to think about it: History is most useful when it is marshaled to overturn received wisdom, not reinforce it. The highest and best use of Spanish flu comparisons may be to poke holes in our own presumptions about what to do.

The deans of this school of thought were Richard Neustadt and Ernest May, two popular Harvard University professors who taught a beloved class on reasoning from history. Their classic 1986 book, Thinking in Time: The Uses of History for Decision-Makers, was designed as a guide for leaders who sought to incorporate history into their work. One of their central case studies shows how American policymakers have, in fact, gotten the lessons of the Spanish flu wrong before.