During the debates of the Second Vatican Council one prelate after another addressed the Fathers of the Council in fluent Latin. That they did so is hardly surprising, for Latin remained the living language of the Roman Catholic Church. What may be surprising, however, is their collective level of fluency. The European prelates in particular displayed in their speeches and lively discussions a near-native mastery of Latin that would have been the envy of Renaissance humanists living five hundred years previously. Among the issues the Council Fathers debated in Latin was the introduction of vernacular languages into the Mass. When they ultimately decided to endorse the use of the vernacular in the Mass it doubtless never occurred to them that the facility in Latin that they took for granted-Latin, after all, was an integral part of their own intellectual patrimony and would remain the official language of the Church-would largely disappear within half a century.