The Twitter account of Pope Francis is almost certainly run by well-meaning officials who post well-meaning tweets in his name, intended to inspire his followers without causing trouble. But one in particular last month set off an energised conversation when it irked Professor Jordan Peterson.

“#SocialJustice demands that we fight against the causes of poverty: inequality and the lack of labour, land, and lodging; against those who deny social and labour rights; and against the culture that leads to taking away the dignity of others.” To which Peterson replied: “There is nothing Christian about #SocialJustice. Redemptive salvation is a matter of the individual soul.” This began a series of colourful conversations about the fuzzy boundaries between salvation, Catholic social teaching and socialism.