One of my constituents once complained to the Beeb about a report on the repression of Mexico’s indigenous peoples, in which the government was labelled Right-wing. The governing party, he pointed out, was a member of the Socialist International and, again, the give-away was in its name: Institutional Revolutionary Party. The BBC’s response was priceless. Yes, it accepted that the party was socialist, “but what our correspondent was trying to get across was that it is authoritarian”.

In fact, authoritarianism was the common feature of socialists of both National and Leninist varieties, who rushed to stick each other in prison camps or before firing squads. Each faction loathed the other as heretical, but both scorned free-market individualists as beyond redemption. Their battle was all the fiercer, as Hayek pointed out in 1944, because it was a battle between brothers.

Authoritarianism – or, to give it a less loaded name, the belief that state compulsion is justified in pursuit of a higher goal, such as scientific progress or greater equality – was traditionally a characteristic of the social democrats as much as of the revolutionaries.