1265-1274 · Rome, Paris, and Naples (composed across multiple locations)

Thomas Aquinas Writes the Summa Theologica

Between 1265 and 1274, the Dominican friar Thomas Aquinas composed the Summa Theologica, a vast synthesis of Christian theology and Aristotelian philosophy that became the most authoritative theological work in Catholic history.

Thomas was a large, quiet Dominican friar who had studied under Albert the Great in Cologne and Paris. His classmates had called him 'the dumb ox,' a nickname Albert corrected with the prediction that this ox's bellowing would fill the world. Albert was right. The Summa was Thomas's attempt to organize the entirety of Christian theology into a single, logically ordered work. It runs to thousands of pages, divided into three parts covering God's existence and nature, the moral life of human beings, and the person and work of Christ. Each question follows the same format: objections to the position, a central argument, and replies to each objection. The method is relentlessly logical but never cold. Thomas addresses questions that range from whether God exists to whether it is sinful to sell wine you know has gone bad. He drew on Aristotle, Augustine, Scripture, the Church Fathers, Jewish and Islamic philosophers — anyone who had something useful to say. His central insight was that faith and reason are not enemies. Grace does not destroy nature but perfects it. This meant that philosophy, science, and human learning were not threats to faith but tools for understanding God's creation. Thomas never finished the Summa. In December 1273, he had a mystical experience during Mass and stopped writing, saying that everything he had written seemed like straw compared to what he had seen. He died three months later. The Church declared him a Doctor of the Church in 1567 and the patron of Catholic schools in 1880.

Why it matters

Produced the most comprehensive and authoritative synthesis of Catholic theology ever written, integrating faith and reason in a framework that the Church officially adopted as its preferred theological method.