Throughout medieval times, the Catholic Church was a dominant sociopolitical power in Western and Central Europe. France had special status in this situation as the fille aînée de l'Eglise (elder daughter of the Church). Then, assertive secularism became the dominant ideology in such a Catholic country. The proponents and opponents of assertive secularism have different perspectives to explain this puzzle as Emile Poulat notes: “Our secularism has one history and two memories.” Beyond this ideological division there are two main approaches to the history of secularism in France. Baubérot attaches importance to continuity in his analysis. For him, the secularization of the French state was a gradual process. He defines the postrevolutionary period (1789–1806) as the first threshold of political secularization and the early Third Republic's secularization reforms (1881–1905) as the second threshold. Pena-Ruiz criticizes Baubérot's process-oriented argument and stresses that there were several moments of back and forth, rather than continuity in the French history of secularism. Pena-Ruiz emphasizes the emergence of the secular state in 1795 and the return to close church-state relations by the Concordat of 1801. According to his perspective, secularization reforms (1881–1905) meant a rupture from the Catholic past, rather than a result of an ongoing process.

These two actually are not mutually exclusive perspectives. While examining the ideological dominance of assertive secularism, I use the change-based approach and take the early Third Republic (1875–1905) as the critical juncture.