The common name for the Second Vatican Council, a council of all the world’s bishops opened by Pope John XXIII in 1962 and closed under Pope Paul VI in 1965. Vatican II ushered in major reforms in the Roman Catholic Church, such as changes in biblical studies, and encouraged bishops and clergy to deal with the challenges of the modern world. It also recognized the importance of the laity in the church and signaled a greater openness to other Christians and non-Christians, including a reconsideration of the church’s attitude toward Judaism. Popularly, Vatican II is perhaps best-known for leading to the saying of Mass in the vernacular, rather than exclusively in Latin. Councils are infrequent — the previous council was Vatican I (1869-70) — and are convened in times of crisis or to resolve especially difficult questions. There is some debate as to whether a council wields greater authority than the pope.