Summa Theologica, (Tertia Pars)

Summa Theologica, (Tertia Pars) is a book by Thomas Aquinas, first published in the late 13th century. This third part of Aquinas’s monumental theological work turns its attention to the mystery of Christ — the Incarnation, the life of Jesus, the Sacraments, and the Resurrection. Written in the rigorous scholastic method that defined medieval theology, this section explores the central doctrines of Christianity with intellectual precision and profound reverence.

It represents the culmination of Aquinas’s effort to unite reason and faith, philosophy and revelation, into a single, harmonious vision of divine truth. Thomas Aquinas, one of the greatest theologians and philosophers of the Middle Ages, drew deeply on the works of Aristotle, Augustine, and Scripture to craft a systematic theology that continues to shape Christian thought to this day.

The Tertia Pars in particular influenced the development of sacramental theology and Christology within both Catholic and broader Christian traditions. Its balanced approach between intellect and devotion made it not only a scholarly cornerstone but also a spiritual guide for those seeking a deeper understanding of the nature of Christ and the path to salvation.

This timeless text provides an essential foundation for understanding classical Christian doctrine, Thomistic philosophy, and the enduring dialogue between reason and faith. This translation by Laurence Shapcote (the Fathers of the English Dominican Province), was first published in 1911.