Thomas Aquinas was born to a noble Italian family who imprisoned him for a year when he insisted on joining the new Dominican Order. He escaped and went to Paris and Cologne, where he became the greatest theologian of the medieval West.
His Summa Theologica is one of the largest and most rigorous works in Christian thought — an attempt to set out the whole of Catholic theology in question-and-answer form, drawing on Augustine, the Fathers, and Aristotle. Near the end of his life, after a mystical experience, he stopped writing: "All that I have written seems to me like straw compared to what has now been revealed to me." He died at 49, on the way to a council, having barely completed his great work.