A historical study of the tension between radical reformers (prophets) and conservative Catholic Church authorities (guardians) in responding to modernity. This book highlights how renewal and fidelity to tradition often clashed within the Church. The author argues that Church institutions often resisted innovation at first, but that renewal ultimately proved crucial to the survival of the faith amidst changing times. The work uses biographical and historical sketches to illustrate this conflict. The author discusses important figures such as John Henry Newman, whose thinking on doctrinal development was often misunderstood in his time. It also examines others such as Pope Benedict XIV and Felicite de Lamennais. This work provides a vivid portrait of the intellectual and spiritual history of the Catholic Church, where renewal and tradition complement each other, though often through a process of heated debate.