A concise biography of Jean-Jacques Olier, the influential 17th-century French priest and founder of the Society of Saint-Sulpice. Written by Bernard Pitaud, a Sulpician priest himself, this work explores Olier's spiritual legacy, his role in reforming clerical training, and his enduring impact on French Catholicism. The book delves into the challenges and internal crises Olier faced, highlighting his characteristic spirituality of 'abandon to the Spirit.' It presents not just a historical account, but also reflects on the modernity of Olier's thought and his relevance to contemporary spiritual life. The narrative situates Olier within the context of 17th-century France, examining his contributions to the Catholic Church and his significance as a figure of religious renewal.