Mariology is the theological study of Mary, the mother of Jesus. Mariology methodically presents teachings about her to other parts of the faith, such as teachings about Jesus, redemption and grace. Christian Mariology aims to connect scripture, tradition and the teachings of the Church on Mary.

There exist a variety of Christian views on Mary ranging from the focus on Marian veneration in Roman Catholic Mariology to Protestant objections, with Anglican Marian theology in between. As a field of theology, in recent centuries the most substantial developments in Mariology (and the founding of specific centers devoted to its study) have taken place within Roman Catholic Mariology. Eastern Orthodox concepts of Mary have been mostly expressed in liturgy and are not subject to a central dogmatic teaching office.

A significant number of Marian publications were written in the 20th century, with theologists Raimondo Spiazzi and Gabriel Roschini achieving 2500 and 900 publications respectively. In terms of popular following, membership in Roman Catholic Marian Movements and Societies has grown significantly. Ecumenical differences continue to exist in substance and style but are more easily understood because of the existence of Mariology.

Louis Bouyer (17 February 1913, Paris – 22 October 2004, Paris) was a French Lutheran minister who converted to Catholicism in 1939. During his religious career he was a scholar who was relied upon during the Second Vatican Council.

He was known for his books on Christian spirituality and its history. Along with Joseph Cardinal Ratzinger and others, he was a co-founder of the international review Communio. He was chosen by the pope to be part of a team to initiate the International Theological Commission in 1969.

Born into a Protestant family, Louis Bouyer, after a receiving a degree from the Sorbonne, studied theology with the Protestant faculties of Paris and then Strasbourg. He was ordained a Lutheran minister in 1936 and served as vicar of the Lutheran parish of the Trinity in Paris until World War II. In 1939, the study of the christology and ecclesiology of St. Athanasius of Alexandria led Bouyer to the Catholic Church.

Received into the Catholic Church in the Abbey of Saint-Wandrille (Seine-Maritime) in 1944, he entered the congregation of the priests of the Oratory, and remained with them the rest of his life. He was a professor at the Catholic Institute of Paris until 1963 and then taught in England, Spain, and the United States. In 1969 he wrote the book The Decomposition of Catholicism, which presented what he saw as the liturgical and dogmatic problems in the Church.