The contemporary Catholic Church finds itself in deep crisis as it questions which elements are essential to the Catholic faith, and which can be changed. Bringing a longue durée perspective to this issue, Michael Seewald historicizes the problem and investigates how theologians of the past addressed it in light of the challenges that they faced in their time. He explores the intense intellectual efforts made by theologians to explain how new components were added to Christian doctrine over time, and that dogma has always been subject to change. Acknowledging the historic cleavage between 'conservatives' who refer to tradition, and reformers, who formulate their arguments to address contemporary needs, Seewald shows that Catholic thought is intellectually expansive, enabling the Church to be transformed in order to meet the challenges of the present day. His book demonstrates how theology has dealt with the realization that there is a simultaneity of continuity and discontinuity in doctrinal matters.