Book excerpt: Even though the policy impact of Catholicism has increasingly been acknowledged, existing scholarship lacks a coherent view on its changing influence over time and in different political contexts. In this book, Fabio Bolzonar investigates the influence of Catholicism on developments in French social protection from World War II to the mid-2010s. He discusses the factors that have favoured or inhibited it and explores the hybridization between Catholic values and secular principles in the social engagement of Catholic actors in secular France. By doing so, this multidisciplinary study integrates current scholarship, which has given limited attention to the changing patterns of Catholic involvement in the social policy domain over a long period of time, and the renewed influence of Catholic values in secularized societies. Catholic mobilization has relocated from the political to the civil society sphere, making voluntary organizations and social movements, rather than political parties, the main channels for defending Catholic values in secular France. Rather than marginalizing Catholicism, this process has opened up new opportunities for Catholic actors and values to play a significant role in society and politics. Bolzonar identifies two divergent scenarios that define Catholic social engagement in contemporary France: either the strengthening of new forms of institutional collaboration between Catholic-inspired philanthropic organizations and public administrations in the interest of socially vulnerable citizens, or the emergence of new ideological conflicts on gender- and sexuality-related issues.