Summa Theologica Part III (Tertia Pars) is volume four in Ukemi Audiobooks’ complete recording of Thomas Aquinas’s momentous work on Christian theology and philosophy.

Born in Sicily in 1225, he was a friar in the Dominican Order, but during his lifetime he was recognised as a leading figure through his writings as a philosopher, theologian and jurist. He was the first major Christian theologian to absorb the ideas of Aristotle, Averroes and other non-Christian figures, a stance that made him a target for criticism. But Dante (1265-1321) was among many who admired him and placed him in 'Paradiso' in The Divine Comedy.

In 1273, it is reported, Aquinas had a mystical experience while celebrating mass that rendered him unable to continue with his writing work. He died three months later, on 7th March 1274, leaving Part III unfinished. However, it remains a substantial conclusion. If, broadly speaking, Part I (Prima Pars) was concerned with theology, and Part II (both Prima and Secunda) with ethics, Summa Theologica Part III (Tertia Pars) focuses on Christ, and in the course of 90 questions, considers the Incarnation and the Sacraments.

As a teacher and example to humanity, Christ was the suitable path to God, Aquinas writes, the incarnation enabling the bringing together of divine and human nature. Meanwhile, the Sacraments enabled grace to be imparted to men, having a direct spiritual effect. The presentation of the discussions in Part III follow the pattern we have become so familiar with from earlier parts with the statement of the question, then a series of objections, further considerations and finally Aquinas’s replies to each of the objections.

Part III is divided into two sections: 'Treatise on the Incarnation' (Questions 1-59), and 'Treatise on the Sacraments' (60-90). Opening with ‘Of the Fitness of the Incarnation’ in six articles, with Article I asking ‘Whether it was fitting that God should become Incarnate’, Aquinas considers the meaning, the role and the purpose of Christ. Other specific topics raised are: ‘Of the Grace of Christ as an individual man’, ‘Of Christ’s Unity of Being’, ‘Of the Priesthood of Christ’, ‘Of Christ as called the Mediator of God and man’. Aquinas moves on to other aspects of Christ’s birth and life with ‘Of the Virginity of the Mother of God’, ‘Of the Annunciation’, ‘Of the matter from which the Saviour’s Body was conceived’, ‘Of Christ’s manner of life’ and ‘Of the Death of Christ’. In opening the 'Treatise on the Sacraments', Aquinas asks ‘What is a Sacrament (in eight articles)’, and goes on to question the ‘Necessity of the Sacraments’, their principal effects (grace), their causes, and the number of the sacraments. In logical order he considers baptism, circumcision, confirmation, the sacrament of the Eucharist and transubstantiation.

The final six questions focus on the sacrament of penance - and it is here that the Summa Theologica as written by Thomas Aquinas comes to a close. He left the work incomplete on his death. This final Part, as with the others, was translated by Father Laurence Shapcote of the Dominican Order, in an extraordinary, sustained effort over decades during the first half of the 20th century. Living, for the most part, a quiet life in South Africa, he dedicated his life to this task which required not only the heighted and sensitive skills of the master translator, but also a remarkable knowledge of theological and philosophical literature from the classical world to the 13th century of Thomas Aquinas.

As it stands, Summa Theologica in total amounts to over two million words, and it has proved to be a remarkable undertaking for Ukemi reader Martyn Swain, who has succeeded in sustaining clarity and interest through the four volumes of the work, which, in its entirety, runs to over 200 hours.