‘Never deny, seldom affirm, always distinguish.’ We should dust off that old Jesuit adage in this season of American rioting.

It may not be quite as mellifluous as ‘persistent perversity provokes the patient pedagogue to produce particularly painful punishment’, but it does suit the case. The death in Minneapolis of George Floyd at the hands – or the knee – of now ex-cop Derek Chauvin was an outrageous abuse of police power.