St. Anselm
St. Anselm was an 11th century Benedictine monk who was born in Italy and eventually became Bishop of Canterbury. Before entering the monastery, he was quite disinterested in his faith. However, he quickly took interest in theology and writing. He is best known for his scholarship and philosophy, which influenced many future theologians, including St. Thomas Aquinas. His most famous works are Monologion and Proslogion which aim to prove both the existence of God and that God is a perfect being through philosophical and theological arguments. He was able to contribute all these writings to the Church while navigating being bishop in a period of much strife and conflict throughout the Church. St. Anselm was named a Doctor of the Church for the great importance of his theological writings, many of which survive today.