A central problem of the reformation was the need to express new, or newly recognised, doctrinal and political realities in the inherited language of the canon law, while adjusting or denying its implications. Revolutionary ideas are of necessity couched largely in familiar words and concepts, whatever the startling underlying assumptions, and this was certainly true of the sixteenth century when newfangledness was taken for falsehood. But sharing the problem with other revolutionary eras did not make it easier for leaders and clerics to distinguish between divine and human, eternal and temporal, with intellectual tools and ancient examples which could be taken to justify any stance. As Melanchthon said, either in humour or resignation, if the early Fathers had only known what trouble future generations would take in their interpretation, they would surely have made their meaning more clear.

This was far from a simply academic problem. As consensus broke down, the tendency was, as Cranmer observed, to call ‘divine institution’ anything that people think well done; yet it was precisely at such moments of fragmentation that winning the intellectual argument seemed so critical. The story of the schismatic and doctrinal conflict in mid-Tudor England can be written round the theme of legal and scriptural authority. In the 1520s Henry VIII's desire for Anne Boleyn and a male heir was expressed in (rival) glosses of Leviticus and Deuteronomy, however irrelevant Charles V's control of Rome makes such antics seem in retrospect. In the subsequent confrontation with the papacy no medieval or dimly pre-historical exemplum was neglected.