Thomas Aquinas

Thomas Aquinas was an Italian Dominican friar, philosopher and theologian of the thirteenth century, the most influential thinker of medieval scholasticism. He set out to show that the philosophy of Aristotle, newly recovered in the Latin West, could be reconciled with Christian faith, and built from the two a vast, orderly system covering God, nature, the human soul, ethics, law and politics. His Summa Theologiae remains a foundation of Catholic theology, and his ideas on natural law and the existence of God are still widely debated.

Thomas was born around 1225 at the castle of Roccasecca, between Rome and Naples, in the Kingdom of Sicily. His father, Landulf, belonged to the noble Aquino family and served the emperor Frederick II. As a younger son Thomas was meant for a career in the church, and at about five he was placed as an oblate at the great Benedictine abbey of Monte Cassino, where his family hoped he would one day become abbot.

When fighting between the emperor and the pope disrupted the abbey, he was sent around 1239 to the university of Naples. There he met the works of Aristotle, then still regarded with suspicion in Paris, and the Dominicans, a new order of preaching friars who lived by begging. In 1244 he joined them. His family was horrified; his brothers seized him on the road and held him at home for about a year. He refused to give in, and was eventually allowed to rejoin the order.

The Dominicans sent him to Paris and then, in 1248, to Cologne, to study under Albert the Great, the most learned scholar of the order. Large and quiet, Thomas was nicknamed "the dumb ox" by fellow students; Albert reportedly predicted that his bellowing would one day be heard across the world. Back in Paris from 1252, he lectured on the Sentences of Peter Lombard, the standard theology textbook, and in 1256 became a master of theology, though opposition to the friars at the university delayed his formal acceptance.

From 1259 he spent about ten years in Italy, teaching at Dominican houses, at Orvieto while the papal court was there, and from 1265 at Santa Sabina in Rome, where he began the Summa Theologiae. In 1268 he was sent back to Paris for a second period as master, a time of fierce debate. On one side were conservative theologians wary of Aristotle; on the other, teachers in the arts faculty who followed the Aristotle commentaries of Averroes and seemed to accept conclusions contrary to faith, such as the eternity of the world and a single intellect shared by all humans. Thomas wrote against both. In 1272 he moved to Naples to set up a Dominican school.

In December 1273, after an experience during Mass whose nature is unknown, he stopped writing, reportedly telling his secretary Reginald that all he had written seemed like straw. Summoned to the Second Council of Lyon, he fell ill on the journey and died on 7 March 1274 at the Cistercian abbey of Fossanova, south of Rome, aged about forty-nine. In 1277 the bishop of Paris condemned a long list of philosophical propositions, some of which touched on Thomas's views, and for a time his teaching was contested, especially by Franciscans. The tide turned: Pope John XXII declared him a saint in 1323, and in 1567 he was named a Doctor of the Church. In 1879 Pope Leo XIII made his thought the model for Catholic education.

Thomas held that faith and reason are two routes to one truth and cannot genuinely conflict. Some truths, such as that God exists, can be known by natural reason; others, such as the Trinity, are known only through revelation, but are never against reason. Philosophy could therefore serve theology without being swallowed by it.

He rejected the argument of Anselm of Canterbury that God's existence follows from the very idea of God. Instead he offered "five ways" that start from features of the world, such as motion, causation, the existence of things that need not exist, degrees of perfection and the apparent purposefulness of nature, and argue to a first cause or source, which "all call God". Central to his metaphysics is the distinction between what a thing is, its essence, and the fact that it is, its existence. In every creature these differ, so creatures receive existence from outside; only in God are they identical. He drew here on Avicenna as well as Aristotle.

Following Aristotle, he described the soul as the form of the body rather than a separate being trapped inside it, so a human is a single unity of soul and matter. Yet he argued that the human intellect works in a way no bodily organ could, and so the soul can survive death.

His ethics combined Aristotle's account of virtue and human flourishing with Christian teaching, adding faith, hope and charity to the classical virtues and placing final happiness in the vision of God. His theory of law distinguished eternal law, God's plan for creation; natural law, the share of it humans grasp by reason, starting from the principle that good is to be done and evil avoided; human law, which must agree with natural law to bind; and divine law revealed in scripture. An unjust law, in his view, lacks the true character of law. He also set out conditions for a just war and discussed when rulers may be resisted. Like most of his contemporaries, he held views now rejected, including the subordination of women and the death penalty for persistent heretics.

Thomas wrote an enormous amount in a working life of about twenty years: the Summa contra Gentiles, a defence of Christian belief by argument; the unfinished Summa Theologiae, organised in thousands of articles, each stating a question, objections, a reply and answers to the objections; disputed questions on truth, the soul and evil; commentaries on Aristotle and on scripture; and hymns for the feast of Corpus Christi. He drew on Augustine of Hippo, Boethius, Islamic and Jewish philosophers such as Maimonides, and Aristotle, whom he called simply "the Philosopher".

Later critics, notably Duns Scotus and William of Ockham, challenged parts of his system, and the movement known as Thomism defended it. His works shaped the Council of Trent, Catholic universities and the twentieth-century revival of natural law theory. He is the central figure of Medieval Christian Philosophy and among the most important thinkers in the history of Italy.