"In August 1879, eighteen months into his pontificate, Pope Leo XIII (formerly Joachim Cardinal Pecci, bishop of Perugia), issued the encyclical letter Aeterni Patris. The aim of the encyclical was to aid and advance the restoration of Christian philosophy, which had fallen into danger and disrepute by adhering to modern trends in secular philosophy, by urging a return to the scholastic thinkers of the Middle Ages, most especially the Angelic Doctor St. Thomas Aquinas, and the related philosophical system of Thomism. The encyclical attempts to clarify the roles of faith and philosophy (later to be covered again in John Paul II's encyclical, Fides et Ratio [[On] Faith and Reason]), showing how most beneficially each may profit from the other."