In 2009 the Catholic Church’s International Theological Commission proposed a fundamental change to the way the Church regarded natural law. It could not be presented “as an already established set of rules that impose themselves a priori on the moral subject”, it said. Instead, “it is a source of objective inspiration for the deeply personal process of making decisions”.

This raised some eyebrows, not least because of the way natural law had consistently been imposed a priori by moral theologians to explain and justify Catholic teaching regarding sex. The most obvious example was the way natural law was invoked as the basis of the case against contraception, for instance in Pope Paul VI’s 1968 encyclical Humanae Vitae.

But that redefinition of the role of natural law was just the opinion of a select group of theologians. Or at least it was until last Friday. That was when Pope Francis gave it the authority of his office when he adopted it as his own, in his apostolic exhortation Amoris Laetitia. At the start of the process of consultation that led up to Amoris Laetitia, including two international synods, a questionnaire had been circulated asking to what extent ordinary Catholics understood natural law. A summary of the responses strongly suggested they did not.