This is the twenty-second volume of The Twentieth Century Encyclopedia of Catholicism. Many of the articles in this encyclopedia are the result of the change in direction in Catholic theological thinking that occurred as a result of Vatican Council II (1962-1965). For the most part these volumes reflect a transition period in the minds of their authors and in the daily experience of the Church. The value in consulting this series today is that we may be able to discern, through comparison to our present situation, where the theologians have succeeded and where they have failed in advancing theological understanding. Each of the contributors has had a career which was lived out in the Catholic Church as it moved from a “pre-conciliar” to a “conciliar” theology. As with any interim literature some contributions were written on the eve of the Council and some after, thus they do not all necessarily reflect the direction in which the Council was headed. The Encyclopedia is an English translation of articles that were written in the authors’ first language, that is, French, Italian or German. For the theologian, scholar, historian, sociologist, or philosopher, the series is an excellent point of departure to investigate the inauguration of the theological mind of Vatican II.