Which saint wrote the Summa Theologica?

The saint who wrote the Summa Theologica was Thomas Aquinas. The work, more accurately titled Summa Theologiae, is Aquinas’s best-known theological synthesis and one of the central texts of medieval scholastic thought.

Aquinas, a thirteenth-century Dominican theologian and philosopher, wrote the Summa as a structured guide to Christian theology. It is arranged around questions and articles: each topic presents objections, a contrasting authority, and Aquinas’s reasoned response. The work addresses God, creation, human purpose, Christ, the sacraments, and the return of humanity to God.

Aquinas began composing it in 1265 and continued working on it until 1274. He did not finish the entire project before his death; the later “Supplement” was compiled largely from material in his earlier Commentary on the Sentences.

The Summa is often confused with Aquinas’s Summa contra Gentiles, another major work. Both are theological treatises, but they were written for different purposes. The Summa Theologiae became especially influential in Catholic theology and later Thomistic philosophy.