Who wrote the theological work “Summa Theologica” in the 13th century?

The story behind the answer

Authored by a 13th-century Dominican friar, the Summa Theologica (c. 1265–1274) is a sweeping synthesis of Christian doctrine built on Aristotelian philosophy and the scholastic method of posing questions, objections, and replies. Intended as a teaching manual for beginners, it systematically treats God, ethics, and Christ, and became a cornerstone of Catholic theology, shaping doctrine from the medieval universities to the Council of Trent. The work remained unfinished when its author stopped writing after a profound mystical experience in 1273. For context, Albertus Magnus was the mentor who helped transmit Aristotle to the West; Peter Lombard’s Sentences was an earlier standard textbook; and Duns Scotus later offered rival analyses within scholasticism.