1033 - 1109
St. Anselm was one of the greatest thinkers of the Middle Ages.
Anselm was born in Aosta, Italy, became a Benedict monk in 1060 in France, and was named arch-bishop of Canterbury in 1093.
Anselm became the founder of Scholasticism and he attempted to use logic to proof the existence of God - a philosophy known as Ontology. He was declared a doctor (teacher) of the church in 1720.
www link :
From the Internet Encyclopedia of Philosophy
The Medieval Sourcebook: