Joan of Arc's name appears in several of Charles Péguy's works. She is the main topic in five of these. The purpose of this thesis was to try to know Péguy by studying those five works, to discover his personality, his aesthetics, and his talent as a polemicist. Péguy appears as an original writer who belonged to no philosophical or literary school. Prom the human point of view, he proudly linked himself with his fellow countrymen, the common people, and a certain group of men of his generation who tried to discover and to defend essential values: Christianity, culture and truth. He proclaimed the primacy of spiritual values, the strong basic qualities of the common people, the worthiness of work and poverty. Except for a few friends who collaborated with him in his literary career, he stood alone, and his life was essentially devoted to his work as a writer and publisher. He made many enemies among orthodox Catholics and among the intellectuals associated with the Sorbonne. He was extremely confident in his own opinions and in his talent as a writer. For that reason, and because he had a deep sense of mission regarding the propagation of the values he associated with Joan of Arc, he was an implacable, punctilious, merciless polemicist who at times lacked fairness, and who wrote some lengthy arguments containing digressions