Certain Sainthood focuses on the expansion of papal authority in the Middle Ages during the Gregorian reform. Well-written and persuasively argued, Donald S. Prudlo asserts that papal infallibility developed organically during this period in tandem with papal canonizations.(READING RELIGION) Prudlo argues that from the modern perspective, Catholics concentrate on canonical or theological history, with little appreciation for the social or cultural meaning of saints and canonization, especially during the medieval period.... But [he] integrates it with cultural history and lived religion during the period when papal centralization led to claims of infallibility in canonization.(American Historical Review)