Thomas Aquinas

Introduction

Thomas Aquinas is the central figure of high medieval Scholasticism and the most influential synthesis of Aristotelianism and Christian theology ever produced. His Summa Theologiae is the most ambitious work of systematic theology in the Western tradition, and the framework it articulated — Thomism — has been an official philosophical position of the Catholic Church since Pope Leo XIII's 1879 encyclical Aeterni Patris. Outside Catholicism, the analytic Thomist movement of the late twentieth century has integrated Aquinas's metaphysics, ethics, and philosophy of mind into mainstream anglophone philosophy.

The historical situation made the achievement possible. The recently translated Aristotelian corpus had reached the Latin West through Arabic and Hebrew intermediaries, posing the question of whether Aristotle could be integrated with Christian doctrine or had to be rejected. Aquinas's life work was the demonstration that integration was possible and the production of the system that achieved it.

Life

Aquinas was born in 1225 at his family's castle of Roccasecca, in southern Italy, the youngest son of a noble Lombard family closely connected to the imperial court. He was sent at age five to the Benedictine abbey of Monte Cassino as an oblate, expected to become a monk and likely abbot. At fourteen he transferred to the University of Naples, where he encountered the new Aristotelian curriculum and, around 1244, joined the Dominican Order — a recent, mendicant, intellectually rigorous order, a choice his family resisted by kidnapping and confining him for over a year. He persisted.

The Dominicans sent him to Cologne to study under Albertus Magnus, the most accomplished Aristotelian of the day, and then to Paris, where he studied for his master's degree and from 1256 held a Dominican chair at the University of Paris. He alternated between Paris and Italy for the rest of his career, teaching at Paris (twice), Naples, Rome, Orvieto, and Viterbo. He served as theological adviser to multiple popes and was the most-asked theological consultant of his generation.

His productivity was extraordinary. He composed at least eight million words across roughly twenty years of teaching, dictating to as many as four secretaries simultaneously. In December 1273, after celebrating Mass, he had what appears to have been a mystical experience that left him unable to continue writing; he reportedly said to his secretary Reginald, all that I have written seems like straw to me. He died three months later, in March 1274, at the abbey of Fossanova, while traveling to the Council of Lyon. He was canonized in 1323.

The problem he worked on

Aquinas's organizing problem was the integration of Aristotelian philosophy with Christian theology. The two traditions had developed largely independently, and on a number of questions appeared incompatible: Aristotle held the world was eternal, denied personal immortality (or was at best ambiguous), located the highest good in philosophical contemplation rather than the vision of God, and gave no role to grace, faith, or scripture. Christian theology required creation in time, personal resurrection, the supernatural end of the beatific vision, and the centrality of revelation. The question was whether these could be held together coherently.

The Latin Averroists at Paris (especially Siger of Brabant) argued they could not be held together as a single truth and proposed instead a double truth doctrine: what was true in philosophy might be false in theology and vice versa. The Franciscan-Augustinian theologians worried that the integration would subordinate revelation to pagan philosophy. Aquinas's answer to both was that nature and grace are distinct but compatible: reason can establish certain truths about God (the existence of God, some attributes), revelation completes and corrects what reason can know, and the two together form a single coherent body of understanding.

Contributions

The five ways

Aquinas's most famous arguments are the Quinque Viae, the five proofs for the existence of God in Summa Theologiae Ia q.2 a.3. They proceed from observed features of the world — motion, efficient causation, contingency, gradation of perfections, the orderliness of natural processes — to the existence of a first principle that the argument concludes everyone calls God. The arguments are compressed; they have been the object of voluminous commentary; the most rigorous contemporary defenders include Edward Feser and David Bentley Hart.

Essence and existence

Aquinas's signature metaphysical move is the real distinction between essence (what a thing is) and existence (that it is). In God alone, essence and existence are identical — God's essence is to exist. In every creature, essence and existence are distinct, and existence is given by an act of God. This metaphysical distinction grounds the whole Thomist account of creation, contingency, and the relationship between God and the world. The doctrine was developed in the early On Being and Essence and integrated throughout the later works.

Natural law ethics

Aquinas's ethics, in Summa Theologiae II-I qq.90–108, develops a comprehensive natural law theory. The eternal law is God's plan for creation; natural law is the rational creature's participation in eternal law, knowable by reason; human law is the specification of natural law in particular societies; divine law is the supplement given by revelation. The framework integrates Aristotelian virtue ethics with Stoic natural-law tradition and Christian theology, and remains the foundation of Catholic moral theology and a major position in contemporary ethics.

Analogical predication

When we say God is good and Socrates is good, is the word good used in the same sense, an entirely different sense, or some third way? Aquinas's answer is analogy of proper proportionality: the term applies to both in a related but not univocal sense. The doctrine resolves a recurring puzzle in religious language and grounds the Thomist account of how human concepts can apply to a transcendent God without either equivocation or anthropomorphism.

The integration of grace and freedom

Aquinas worked out a careful position on the relationship between divine grace and human freedom that became the standard high-Scholastic answer: grace does not override freedom but operates within it, perfecting the will without coercing it. The position holds the middle ground between Augustinian pessimism about fallen freedom and Pelagian optimism about unaided will. Subsequent debates between Dominicans (Bañezians) and Jesuits (Molinists) in the sixteenth and seventeenth centuries refought the question on Thomist ground.

Key works

• Summa Theologiae (1265–1274). The summit. Three parts: God; the human person's return to God; Christ and the sacraments. Left unfinished at his death; the missing sections of part III were assembled from his earlier writings.
• Summa Contra Gentiles (1259–1265). A more apologetic earlier summa, addressed to Christians arguing with Muslims, Jews, and pagans.
• On Being and Essence / De Ente et Essentia (1252–1256). The early metaphysical work that lays out the essence-existence distinction.
• Disputed Questions / Quaestiones Disputatae. Records of formal academic disputations: De Veritate, De Potentia, De Anima, and others.
• Commentaries on Aristotle. Twelve commentaries on Aristotelian works (the Nicomachean Ethics, Politics, Physics, De Anima, Metaphysics, and others); among the most influential commentaries on Aristotle in the Western tradition.
• Commentaries on Scripture. Substantial exegetical works on Paul, the Gospels, the Psalms, Job.

Influences and influenced

Influenced by: Aristotle (foundational); Augustine (the second great authority, especially on grace and the will); Pseudo-Dionysius (for the doctrine of analogy and negative theology); the Islamic philosophers, especially Avicenna (the essence-existence distinction has Avicennian roots) and Averroes (the great commentator on Aristotle, against whose interpretations Aquinas often defines his own); Albertus Magnus (his teacher); Peter Lombard's Sentences; the Greek and Latin Christian fathers generally.

Influenced: the high-medieval Dominican school (the Thomists, including Cajetan, John of St. Thomas); the Council of Trent (which adopted Thomist categories); the Second Scholastic in Spain (Francisco Suárez, Domingo de Soto); the Roman tradition of moral theology and canon law; Catholic philosophy after Leo XIII's 1879 endorsement (Gilson, Maritain, Lonergan, John Paul II's Fides et Ratio); analytic Thomism (Anthony Kenny, Eleonore Stump, John Haldane, Brian Davies); and contemporary natural law theory (Germain Grisez, John Finnis, Robert P. George).

Reception

Aquinas's contemporary reception was contested. Within three years of his death, several of his theses were condemned at Paris and Oxford in the Condemnations of 1277 — the most consequential disciplinary action against a major theologian in the medieval Church. The Dominican order defended him vigorously; the Franciscans, defending the Augustinian alternative, opposed. He was canonized in 1323, and the Condemnations were partially rescinded in 1325.

He became the standard authority of the Dominican school and one of two or three central authorities in the late-medieval university. The Renaissance and the Reformation displaced him substantially in Protestant settings, but he remained central in Catholic philosophy. The Council of Trent (1545–1563) deliberated with Aquinas's Summa on the altar.

The modern Thomist revival began in the late nineteenth century. Pope Leo XIII's encyclical Aeterni Patris (1879) made Thomism the recommended philosophy of Catholic education and seminary training; the resulting Neo-Thomist movement produced figures of substantial influence (Étienne Gilson, Jacques Maritain, Réginald Garrigou-Lagrange) and shaped Catholic intellectual life for nearly a century. The Second Vatican Council (1962–1965) loosened the strict requirement, and later 20th-century Catholic theology became more pluralistic, but Thomism remained a major option.

The most striking recent development is analytic Thomism, a movement initiated by Anthony Kenny's 1969 monograph on Aquinas and developed by Peter Geach, Elizabeth Anscombe, Brian Davies, Eleonore Stump (whose Aquinas, 2003, is the standard contemporary commentary), and many others. Analytic Thomism has integrated Aquinas's metaphysics, philosophy of mind, and ethics into the mainstream of anglophone philosophy in ways that would have surprised an earlier generation.

Continuing engagement

Current scholarship on Aquinas is centered in journals including The Thomist, Nova et Vetera, Angelicum, and Doctor Communis, and is institutionally supported by the Pontifical Academy of St. Thomas Aquinas, the Thomistic Institute, and academic departments at Catholic universities worldwide. Major recent monographs include Stump's Aquinas, Robert Pasnau's Thomas Aquinas on Human Nature (2002), Brian Davies's The Thought of Thomas Aquinas (1992), Edward Feser's Aquinas: A Beginner's Guide (2009), and Fergus Kerr's After Aquinas (2002). The Leonine Commission continues its century-long project of producing definitive critical editions of the complete works; the digitization of the Aquinas corpus through the Corpus Thomisticum has made the texts and concordances freely available online.

Further reading

• Aristotle — the philosopher he synthesized with Christian theology
• Augustine — the prior theological authority
• Summa Theologiae — the central work
• Scholasticism — the tradition he brought to its peak
• Aristotelianism — the philosophical tradition his work is the supreme Christian inheritor of
• Christian Theology — the tradition his synthesis defined for centuries

The high-medieval synthesis of Aristotle and Christianity. Foundational for Catholic philosophy and a major figure in contemporary analytic metaphysics.