The nineteenth century was probably the most traumatic and confusing period in French history—were you to include the last decade of the eighteenth century, you could remove the 'probably'. Politically, the Empire veered from republic at the beginning, middle and end, two Bonapartist imperial regimes, a Bourbon revival, and a King that tried to be both Bonapartist and Bourbon.
Religiously it was a period of revival. Benedictine Monasticism was got going again by the great Guéranger at Solesmes and spread rapidly, with other orders also being founded. There was vast number of instances of a relatively new phenomenon—women's active religious orders, some founded in the wake of the revolution to provide care and instruction to those who needed either, without the constriction of enclosure. It used to be said that even God did not know how many female religious orders there were in France (nor how much money the Franciscans had, nor what a Jesuit was thinking—no doubt there are others). There were saints, too, perhaps outstandingly St Thérèse of Lisieux.
The monasticism soon came to be what one thinks of as being 'real' monasticism today. In other words, a community dedicated to contemplation, prayer and plainchant. Guéranger unquestionably thought that he was reviving the monasticism of the Middle Ages, but really I think that French-style monasticism owes more to the Gothic Revival which was just as powerful in France as it was in England. It has long been my view that the English Benedictine Congregation, with its schools and parishes, is closer in spirit to mediæval monasticism than the various French congregations. Be that as it may, revival gothicism caught the spirit of the age more effectively, and Benedictinism flourished.
The close of the nineteenth century saw the secularists triumphant. But only just. The Third Republic that followed the Franco-Prussian war and the flight of Napoleon III to the safety of the Home Counties was on the one hand deeply in the hands of the secularists, increasingly dominated by the Freemasons (a much tougher, atheistic, breed than our home-grown kindly-motivated rotarian-writ-large trouser-rollers), but also traumatized by the events of 1870 when, besieged by the Germans, the poor starving people of Paris were driven to eat rats and the rich ate the exhibits from the Paris Zoo, to be followed by the anarchy of the Communards. In the Commune, the Archbishop of Paris was assassinated, and he became a sort of common focus of national angst which meant that the state was kind-of atheistic but with a religious twist.
The building of the great basilica of Sacre-Coeur on Montmartre was, in a way, the last flourish of the Ancien Regime, the alliance of throne and altar. In the late seventeenth century St Margaret Mary had given instructions that France was to build a great church in honour of the Sacred Heart, or else terrible tribulations would befall the country. This was later understood to be a prophecy of the Revolution and its attendant horrors. Sacre-Coeur was built with the active co-operation of the civil authorities, and even with a decree of the Assemblee-Nationale in 1910, saying that it was in reparation for the crimes of the Commune.
And yet while all this was going on, the arch-mason and secularist Georges Clémenceau was organizing the expulsion of huge numbers of male and female religious from France. Even Solesmes Abbey was closed, and the monks took refuge on the Isle of Wight, where they lived between 1901 and 1922.
So France, then, has this bifurcated understanding of herself: on the one hand profoundly Catholic, and on the other profoundly secular.