As I write this, Europe and the wider world is trying to come to terms with the Paris tragedy. Initially, all I could do was join with millions of others and express my sympathy for, and solidarity with, the French. Like villages, towns and cities across the globe, Birmingham lit up its buildings in red, white and blue, held vigils and observed the Europe-wide minute of silence. #ViveLaParis went viral.

Expressing concern and grief for the bereaved and injured are, of course, natural human emotions. But so are anger and the desire for retribution. And almost as soon as the outpourings of compassion were expressed, so were the calls for revenge heard.