Bernard Henri Levy’s latest book, The Virus in the Age of Madness, contains a striking quote from Rudolf Virchow, the 19thcentury father of pathological anatomy: ‘An epidemic is a social phenomenon that has some medical aspects’. He was right. Catastrophes are society’s great illuminators. From Pompeii to coronavirus, the governing axiom is clear: if you want to discover the essence of something, stress test it.