In the Middle Ages, theology was “the queen of sciences” because it involved the study of God, who made all knowledge possible. Paris became the place to study theology. In the first decades of the twelfth century, students from across Europe crowded into the cathedral school of Notre Dame (NOH-truh DAHM) in Paris.

University professors were known as “schoolmen” or Scholastics. They developed a method of thinking, reasoning, and writing in which questions were raised and authorities cited on both sides of a question. The goal of this method was to arrive at definitive answers and to provide rational explanations for what was believed on faith.

The Scholastic approach rested on the recovery of classical philosophical texts. Ancient Greek and Arabic texts entered Europe in the early twelfth century by way of Islamic intellectual centers at Baghdad, Córdoba, and Toledo (see Chapter 8). The major contribution of Arabic culture to the new currents of Western thought rested in the stimulus Arabic philosophers and commentators gave to Europeans’ reflections on ancient Greek texts and the ways these texts fit with Christian teachings. One of the young men drawn to Paris was Peter Abelard (1079–1142). Abelard was fascinated by logic, which he believed could be used to solve most problems. He was one of the first Scholastics, and commented, “By doubting we come to questioning, and by questioning we perceive the truth.” Abelard was severely censured by a church council, but his cleverness, boldness, and imagination made him a highly popular figure among students.

Abelard’s reputation for brilliance drew the attention of one of the cathedral canons, Fulbert, who hired Abelard to tutor his intelligent niece Heloise. The relationship between teacher and pupil passed beyond the intellectual. Heloise became pregnant, and Fulbert pressured the couple to marry. The couple agreed but wanted the marriage kept secret for the sake of Abelard’s career. Furious at Abelard, Fulbert hired men to castrate him. Abelard persuaded Heloise to enter a convent, and he became a monk.

In the thirteenth century, Scholastics devoted an enormous amount of time to collecting and organizing knowledge on all topics. Such a collection was published as a summa (SOO-muh), or reference book. Saint Thomas Aquinas (1225–1274), a Dominican friar and professor at Paris, produced the most famous of these collections, the Summa Theologica, a summation of Christian ideas on a vast number of theological questions, including the nature of God and Christ, moral principles, and the role of the sacraments. In this and many of his other writings, Aquinas used arguments that drew from ancient Greek philosophers, especially Aristotle, as well as earlier Christian writers.

In all of his works, Aquinas stressed the power of human reason to demonstrate many basic Christian principles, including the existence of God. To obtain true Christian understanding, he wrote, one needed both reason and faith. His ideas have been extremely influential in both philosophy and theology: in the former through the philosophical school known as Thomism, and in the latter especially through the Catholic Church, which has affirmed many times that they are foundational to Roman Catholic doctrine.