In one of the snarling outbursts that are becoming a worrying feature of his pontificate, Pope Francis recently likened the media’s fixation with public scandals to ‘coprophagia’ – that is, the habit of eating faeces. The Pope’s champions had a hard time explaining that one. The best they could come up with was the suggestion that references to excremental fetishes are a well-loved feature of Buenos Aires demotic – news to most Argentinians, I suspect.

Had Francis’s defenders read Roy Hattersley’s new history of British and Irish Catholics, they could have done better by pointing out that there is a saintly precedent for scatological invective. Thomas More’s name for Martin Luther was ‘Father Toss Pot’. Luther, he claimed, allowed ‘nothing in his mouth but