Lord Halifax wrote in 1690 that ‘the struggle for knowledge hath a pleasure in it like that of wrestling with a fine woman’. While French scholars can seldom be accused of faint-heartedness in fighting the good fight, they also have a shrewd eye for assessing opponents with whom it is wiser not to tangle. This presumably explains why the main theme of this book has not been previously addressed by any of the numerous French historians who would be far better placed to attempt it than I have been.

The greater part of this text is based on the Wiles lectures which I was privileged to give in 1986. The Wiles Trustees specify that the lectures should be ‘broad in character and of a pioneering nature’. This is not an easy combination, since innovatory research by an individual tends necessarily to take place on a fairly narrow front – while any attempt at innovation on a broad scale inevitably invites accusations of being merely speculative. I hoped that my subject, spanning a century of change, would meet the criterion of breadth, and that the untried nature of my theme would provide the pioneering spirit that the Trustees were seeking to stimulate.

Readers should therefore not expect a general survey of religious issues in French politics, even if the intelligibility of the book's main theme has required a fair amount of this background to be sketched in. Its prime aim is to examine the problems that committed Catholics allegedly faced if they sought careers in state employment in France – more particularly in the branches that were regarded as politically sensitive.