Thomas Aquinas

Thomas Aquinas was a Dominican friar, priest, theologian and philosopher who lived from about 1225 to 1274. He taught at the University of Paris, the leading centre of theology in Europe, and in several cities in Italy. In a working life of only about twenty-five years he wrote more than eight million words.

His great aim was to show how human reason and Christian faith fit together. At the time, the works of the ancient Greek philosopher Aristotle, together with commentaries by Muslim and Jewish thinkers, had recently become available in Latin. Some Christians feared that this philosophy contradicted their faith. Thomas argued that truth cannot contradict truth: rightly used, philosophy helps faith understand itself, while faith points reason beyond what it can reach on its own.

Thomas is the most influential thinker of the medieval Latin West. In the Catholic Church he is honoured as a saint and a Doctor of the Church, and his thought became the backbone of Catholic philosophy and theology. His ideas about ethics, law, human nature and God are still discussed by philosophers of many traditions.

Thomas was born around 1225 at Roccasecca, a castle of the counts of Aquino between Rome and Naples. At about five years old he was placed as an oblate at the great Benedictine abbey of Monte Cassino; his family probably hoped he would one day become its abbot. When war between Emperor Frederick II and the pope reached the abbey in 1239, Thomas was sent to study at the new University of Naples, where he first encountered the works of Aristotle.

In Naples he met the Dominicans, a mendicant order founded only a few decades earlier by St Dominic. Its friars lived in poverty, begged for their living, and devoted themselves to study and preaching. In 1244 Thomas joined them. His family was furious. On his way north, his brothers seized him and held him at the family castles for about a year. Later stories say they even sent a woman to tempt him, whom he drove away with a burning stick; true or not, the episode shows how determined he was remembered to be. In 1245 his family released him.

Thomas then studied under the Dominican scholar Albert the Great, in Paris and from 1248 in Cologne. Albert, a scientist and philosopher of enormous learning, was one of the first Latin thinkers to take on the whole of Aristotle. Thomas’s quiet manner earned him the nickname “the dumb ox”; the story of Albert’s prediction that his bellowing would be heard throughout the world comes from early biographies.

In 1252 Thomas was sent to Paris to lecture on the Sentences of Peter Lombard, the standard theology textbook. In 1256 he became a master of theology, holding one of the Dominican chairs until 1259. These were years of conflict: some secular (non-friar) masters at the university fought to exclude the mendicant friars, and Thomas wrote in their defence.

From 1259 to 1268 he worked in Italy, in the Dominican houses of Naples, Orvieto (where the papal court often resided) and Rome, where he organized a school for young friars at Santa Sabina. There he completed the Summa contra Gentiles and began the Summa Theologiae.

In 1268 he returned to Paris for a second, unusually intense period as master. He argued on several fronts at once: against conservative theologians who distrusted Aristotle, against “radical Aristotelians” in the arts faculty, and against critics of the friars. In 1272 he went back to Naples to set up a Dominican school of theology.

On or around 6 December 1273, while celebrating Mass, Thomas had an experience that made him stop writing. According to his companion Reginald of Piperno, as reported in the canonization inquiry, he said that everything he had written seemed like straw compared with what he had seen. Summoned to the Second Council of Lyon, he fell ill on the journey and died at the Cistercian abbey of Fossanova on 7 March 1274, aged about forty-nine.

Thomas lived at a turning point in European intellectual history. Around 1200, universities appeared in Paris, Oxford, Bologna and elsewhere as guilds of masters and students. Teaching took the form of lectures on authoritative texts and formal “disputations”, in which a question was argued from both sides. This method, known as scholasticism, shaped the structure of Thomas’s writing.

At the same time, translators working in Toledo, Sicily and elsewhere had made almost all of Aristotle’s works available in Latin, often via Arabic, along with the great commentaries of Avicenna (Ibn Sina) and Averroes (Ibn Rushd) and the writings of the Jewish philosopher Moses Maimonides. Thomas’s fellow Dominican William of Moerbeke produced new translations directly from the Greek, some possibly at Thomas’s request, though the extent of their collaboration is debated.

Aristotle offered a powerful, systematic account of nature, the soul, ethics and politics, but some of his views seemed to clash with Christian teaching, for example that the world had always existed. Averroes’s interpretation seemed to imply that all human beings share a single intellect, which would undermine personal immortality. Church authorities in Paris restricted the teaching of Aristotle’s natural philosophy several times in the early thirteenth century. How to deal with this new learning was the great intellectual question of Thomas’s generation.

Thomas was not alone in facing this question. His teacher Albert the Great embraced Aristotle’s natural science with enthusiasm; his Franciscan contemporary and fellow Paris master Bonaventure was more cautious, stressing the Augustinian tradition and the limits of philosophy; and arts masters such as Siger of Brabant pursued Aristotle’s arguments even where they led away from Christian doctrine. Thomas’s distinctive path lay between these positions: he accepted Aristotle’s philosophy as largely true while correcting it where he judged it mistaken.

Thomas’s writings fill dozens of volumes. His early Commentary on the Sentences (1252–1256) and the short treatise On Being and Essence (De ente et essentia) set out the metaphysical ideas he would develop throughout his life. Disputed questions such as On Truth (De veritate) and On the Power of God record academic debates he conducted as master.

The Summa contra Gentiles (c. 1259–1265) is a four-book defence of Christian belief, which proceeds as far as possible by reason alone in its first three books, because it addresses readers who do not accept Christian scripture. Its exact purpose, whether as a missionary handbook or a general work of philosophical theology, is debated.

The Summa Theologiae, begun around 1265–1268 and left unfinished, is his masterpiece, intended as an orderly introduction to theology for beginners. It has three parts: the first on God and creation; the second on human action, virtue and happiness (itself divided into two halves); and the third on Christ and the sacraments. It contains over five hundred questions divided into more than 2,500 articles. After his death his followers completed it with a Supplement drawn from his earlier writings.

Thomas also wrote commentaries on Aristotle’s major works, on books of the Bible such as Job, the Gospel of John and the letters of Paul, on the Neoplatonic Book of Causes, and on Boethius and Pseudo-Dionysius. He is traditionally credited with the liturgy for the feast of Corpus Christi, including hymns such as Pange lingua, which are still sung.

Each article of the Summa Theologiae follows the same pattern, drawn from university disputations. It opens with a yes-or-no question, for example “Whether God exists?”. Next come the objections: usually three or more arguments for the view Thomas will reject, often stated at their strongest. Then a short sed contra (“but on the contrary”) cites an authority for the other side.

The heart of the article is the respondeo (“I answer that”), where Thomas explains his own position, often by drawing distinctions. Finally he replies to each objection in turn, showing what is true in it and where it goes wrong.

This format trains readers to take opposing views seriously, to state them fairly and to answer them point by point. Many modern teachers of philosophy still admire it as a model of rigorous and charitable argument.

Faith and reason. Thomas distinguished truths that reason can reach, such as that God exists, from truths known only through revelation, such as the Trinity. Theology, he argued, is a science that reasons from revealed principles, while philosophy reasons from what is naturally known. Because both come from God, they cannot truly conflict; an apparent conflict signals an error in reasoning.

The Five Ways. In the Summa (Part I, question 2, article 3) Thomas offers five brief arguments that God exists, reasoning from motion, from efficient causes, from contingency, from degrees of perfection and from the order of nature. Each argues from features of the world to a first cause or ultimate explanation, “and this everyone calls God”. These arguments are among the most discussed in the philosophy of religion.

Being and essence. For Thomas, in every created thing what it is (its essence) is distinct from the fact that it is (its existence, esse). Only in God are essence and existence identical: God is subsistent being itself. Creatures participate in being received from God. Many scholars see this as Thomas’s most original contribution to metaphysics.

Human nature, ethics and law. Following Aristotle, Thomas held that the soul is the form of the body, so a human being is a single unity of body and soul. The goal of human life is happiness, ultimately found in knowing God. The virtues, such as prudence, justice, courage and temperance, perfect human nature, while grace perfects it further. Natural law is our rational participation in God’s eternal law, whose first principle is that good is to be done and evil avoided. His discussion of when war can be just, with legitimate authority, just cause and right intention, became a foundation of just war theory.

Thomas’s views were controversial in his own time. In 1277, three years after his death, Bishop Étienne Tempier of Paris condemned 219 propositions, mainly aimed at radical Aristotelians in the arts faculty; some condemned theses resembled positions Thomas had held, for example on the unity of substantial form. The same year Archbishop Robert Kilwardby at Oxford condemned related theses. Franciscan critics produced “corrections” of his work, and Dominicans replied in defence.

The tide turned quickly. Pope John XXII canonized Thomas in 1323, and in 1325 the Paris condemnation was revoked insofar as it touched his teaching. Commentators such as John Capreolus in the fifteenth century and Cardinal Cajetan in the sixteenth built the tradition known as Thomism. The Council of Trent drew heavily on his theology, and Pope Pius V declared him a Doctor of the Church in 1567.

In 1879 Pope Leo XIII’s encyclical Aeterni Patris called for the restoration of Thomas’s philosophy in Catholic education, launching the Neo-Thomist revival. In the twentieth century thinkers such as Jacques Maritain and Étienne Gilson applied his ideas to modern questions of politics, human rights, art and history. Thomas’s influence also reached Dante, whose Divine Comedy presents him as a guide in the heaven of the Sun, and Protestant and secular thinkers who engaged critically with his work.

Like any thinker, Thomas shared many assumptions of his time that are now widely rejected. Following Aristotle’s biology, he described woman as in some sense a “defective” male in terms of generation, while also insisting that woman was created in the image of God and was not a failed creation in the order of nature’s intention. Feminist scholars have examined these texts critically, while others have sought to separate his core principles from outdated science.

Thomas also argued that heretics who persistently refuse correction could rightly be handed over to secular authorities for execution (Summa II-II, question 11), a view that supported the practices of medieval inquisitions. He opposed forced baptism of Jewish children and taught that Jews should not be compelled to accept the faith, but he also accepted legal restrictions on Jews common in his society. Modern readers, including Catholic theologians, have criticized these positions.

Philosophically, critics from the Franciscan tradition (such as Duns Scotus and William of Ockham), from early modern philosophy and from contemporary analytic philosophy have challenged his arguments, including the Five Ways and his account of analogy in speaking about God. Defenders reply that many criticisms misread his arguments by detaching them from their Aristotelian framework. These debates remain lively.

Biographical sources. The main early lives are by William of Tocco, who promoted Thomas’s canonization (written c. 1318–1323), Bernard Gui and Peter Calo, together with testimonies collected at the canonization inquiries in Naples (1319) and Fossanova (1321). These texts are hagiographical and include miracle stories, so historians use them carefully. Jean-Pierre Torrell’s Saint Thomas Aquinas, Volume 1: The Person and His Work (Catholic University of America Press, 1996; revised 2005) is the standard modern critical biography, and chronology of individual works is still being refined.

Texts. The Leonine Commission, established by Leo XIII in 1880, has been producing a critical edition of Thomas’s works for well over a century and has not yet finished. Some works long attributed to him are now judged spurious, while the dating of others, such as the Summa contra Gentiles and some Aristotle commentaries, is debated.

Interpretation. Twentieth-century scholars argued over what is most distinctive in Thomas. Gilson emphasized the primacy of existence (esse) and called Thomas’s philosophy “existential”; Cornelio Fabro and Louis-Bertrand Geiger highlighted the Neoplatonic theme of participation; others read him as essentially an Aristotelian. Another debate concerns the relation between philosophy and theology in his work: whether a self-standing “Thomistic philosophy” can be extracted from his theological writings, or whether his philosophy must always be read within his theology.

Recent trends include “analytic Thomism”, influenced by philosophers such as Elizabeth Anscombe and Peter Geach, which brings his ideas into dialogue with contemporary philosophy of mind and ethics; the revival of virtue ethics, in which Alasdair MacIntyre drew heavily on Thomas; and renewed attention to Thomas as a biblical commentator and to his debts to Islamic and Jewish philosophy.