Saint Thomas Aquinas

Commentaries on Aristotle

From the 1260s, at Orvieto, Rome, and Paris

Thomas commented on the Physics, the Metaphysics, the Ethics, the Politics, On the Soul, and other works, using the Latin translations of his century. He did not baptise Aristotle by force. He took a pagan instrument and asked what it could say about act and potency, the soul, and the good, and then he refused every sentence that could not stand under the Creed. The commentaries are philosophy. They are not the Faith. They are why his theology has bones.

Biblical commentaries

Throughout his teaching life

He commented on Job, the Psalms, Isaiah, Jeremiah, the Gospels of Matthew and John, and the Pauline letters. The Catena aurea is a chain of the Fathers on the four Gospels, which he gathered so that a master would not preach his own cleverness. If you want Thomas the theologian, start with John and with Romans, not with a quotation torn out of the Summa.

De ente et essentia

Early, about 1252–1256, for his brothers at Paris

On Being and Essence. A short work on what it is for a thing to be, and how essence stands in creatures and in God. It is the grammar under the later articles on creation. God is not a being among beings who happens to be larger. His essence is His existence. Creatures have their existence as a gift.

Commentary on the Sentences

1252–1256, the bachelor’s task at Paris

Peter Lombard’s Sentences were the textbook. Thomas’s commentary is his first large theology: God, creation, the Incarnation, the Sacraments, the last things. He later changed his mind on some articles. The Summa is the mature form. The Sentences commentary is the workshop, and it is still read because some questions are treated there at a length the Summa cuts.

Summa contra Gentiles

About 1259–1265

Written, by an old report, as a book a missionary could take. The first three books argue as far as reason can go, with Jews, Muslims, and philosophers who do not share the New Testament. The fourth book turns to the Trinity, the Incarnation, and the Sacraments, which reason cannot reach and can only receive. It is not a debate-club manual. It is a long courtesy to people who do not yet believe.

De regno

To the king of Cyprus, unfinished

On kingship. Thomas asks what a king is for. The answer is the common good, not the king’s pleasure, and the highest common good is not a full treasury but a people who can come to God. He is not a modern democrat and not a flatterer of princes. A ruler who will not serve the good may be resisted. The treatise breaks off. What remains is enough to shame a politics that thinks the Church should stay in the sacristy.

Summa theologiae

1265–1273, unfinished

Three parts. The first is God and creation. The second is the journey of the human being to God: the moral life, the virtues, the gifts, the states of life. The third is Christ, the Sacraments, and, unwritten at his death, the last things, which his companions supplied from the Sentences commentary. He stopped writing after Mass on 6 December 1273 and said that what he had written seemed like straw. He died on 7 March 1274 at Fossanova, on the way to the Council of Lyons. The Church names him a Doctor. The Church does not say the Summa is revelation. The Church says it is a sure teacher of the Faith that has been revealed.

The Summa Theologiae

The English Dominican translation

The full Summa Theologiae, in the translation of the Fathers of the English Dominican Province, second and revised edition, 1920. The translation is free to use. Choose a part, then a question. The articles are the text itself: objections, the sed contra, the body, and the replies.