 Pius XII explained the Catholic faith in 41 encyclicals and almost 1000 messages and speeches during his long pontificate . Mediator Dei clarified membership and participation in the Church . The encyclical Divino <unk> Spiritu opened the doors for biblical research . His magisterium was far larger and is difficult to summarize . In numerous speeches Catholic teaching is related to various aspects of life , education , medicine , politics , war and peace , the life of saints , Mary , the Mother of God , things eternal and contemporary . Theologically , Pius XII specified the nature of the teaching authority of the Church . He also gave a new freedom to engage in theological investigations . 
