If it does nothing else, the Covid-19 pandemic provides an opportunity for some sober reflection on the tension between scientific reasoning and human irrationality. The self-enforced lockdown in the UK is a response to a global crisis that threatens to overwhelm an already fragile health service, inflict a death toll unprecedented in my lifetime (I’m 63), and do untold economic harm.

Yet despite clear warnings of the risks of contagion and the need to maintain social distance, we’ve been confronted with scenes of crowds gathering at Britain’s beaches and tourist spots in the warm spring sunshine, or crammed together on rush-hour tube trains. What were they thinking?

Actually, irrational behaviour is not so difficult to understand. The simple truth is that we have created for ourselves a world that is far more complex than any individual human mind can ever hope to fathom. We have invented extraordinary social structures to help us earn a living, care for us, protect us from harm, and to manage trade among ourselves in an increasingly connected world.