In the opening chapter of his pontificate, Pope Leo XIV has issued a stirring call for the Church to embrace a renewed missionary dynamism. This appeal not only reawakens the Church’s evangelical mandate but also prompts reflection on the intellectual wellsprings that might sustain such a renewal. Among these, the legacy of the 19th-century French Catholic philosopher Léon Ollé-Laprune (1839–1898) stands out as particularly resonant. His work offers a compelling vision for how the Church might engage with modern culture. Moreover, his deep admiration for Leo XIII lends a sense of historical continuity to the present moment, as another Leo takes his place upon the Chair of Peter.