ST. THOMAS AQUINAS (1224-1274): Saint Thomas Aquinas, a Dominican theologian, met the challenge posed to Christian faith by the philosophical achievements of the Greeks and Arabs. He effected a philosophical synthesis of faith and reason that is one of the greatest achievements of medieval times. Thomas d'Aquino, the son of a count, was born in his family's castle at Roccasecca, central Italy, in 1224. At about the age of 5, Thomas was placed by his parents in the Benedictine monastery at Monte Cassino. His uncle had been abbot of the monastery, and his family had similar ambitions for Thomas. When Monte Cassino became the scene of a battle between papal and imperial troops, however, Thomas withdrew and enrolled at the University of Naples. There he came into contact with members of the Dominican order and, against the violent opposition of his family, became a Dominican friar in 1244. He then went north to study (1245-52) at Paris and Cologne under Albertus Magnus. The rest of Thomas's life can be divided roughly into four parts. From 1252 to 1259, Thomas taught at the Dominican studium generale (house of studies) in Paris; he was named a master of theology in 1256. From 1259 to 1269 he was in Italy, attached to the papal court. A second Parisian period, 1269-72, was followed by his assignment to Naples to head the Dominican studium generale there. In 1274, going north again to attend the Council of Lyon, Thomas fell ill and died in the Cistercian abbey of Fossanova on March 7. His Summa contra Gentiles was written in 1258-60, and his greatest work, the Summa Theologiae, occupied him from 1267 to 1273. He also wrote commentaries on Aristotle and the Bible. Unlike many theologians, he welcomed the Latin translation of Aristotle's complete writings, although he opposed the radical advocates of Aristotelianism, the so-called Latin Averroists. Thomas's thought embodied the conviction that Christian revelation and human knowledge are facets of a single truth and cannot be in conflict with one another. Humans know something when its truth is either immediately evident to them or can be made evident by appeal to immediately evident truths. They believe something when they accept its truth on authority. Religious faith is the acceptance of truths on the authority of God's revelation of them. Despite the fact that this seems to make knowledge and faith two utterly distinct realms, Thomas held that some of the things God has revealed are in fact knowable. He called these "preambles of faith," including among them the existence of God and certain of his attributes, the immortality of the human soul, and some moral principles. The rest of what has been revealed he called "mysteries of faith," for example, the Trinity, the incarnation of God in Jesus Christ, the resurrection, and so on. He then argued that, if some of the things God has revealed can be known to be true, it is reasonable to accept the mysteries as true. Thomas's conviction that truth is ultimately one because it has its source in God explains the confidence with which he approached the writings of non-Christian thinkers: Aristotle, the Muslim Aristotelians Averroes and Avicenna, and the Jewish philosopher Maimonides. He strongly opposed the Latin Averroists who claimed that something can be true in natural knowledge and false for belief and vice versa. Thomas was critical of the Platonic conception of humans as rational souls inhabiting powerless, material bodies that had been incorporated into the traditional Augustinianism. Like Aristotle, he saw the human being as a complete union of soul and body. Thus, in addition to the survival of the soul after death, the resurrection of the body seemed philosophically appropriate as well as religiously true to Thomas. His Aristotelianism also led to his defense of sense perception and the view that intellectual knowledge is derived by way of abstraction (concept formation) from sense data. Plato's doctrine of Forms, or Ideas, had become part of a traditional realism with regard to universals, part of a theory of knowledge that held that humans have direct knowledge of immaterial entities. Thomas reinterpreted Ideas as divine creative patterns and Saint Augustines's theory of illumination, or the attainment of knowledge of the immaterial through intellectual insight, as a version of the Aristotelian active intellect, which he understood as the faculty of abstracting universal meanings from particular empirical data. Thomas argued that the existence of God can be proved by such reasoning from sense data. He further argued that human concepts and language can be extrapolated, by way of analogy, to speak of God's nature. This, however, is a difficult task, and it is fitting that revelation provides humans with that knowledge. Thomas also held that there are first principles of moral reasoning that all humans grasp; many of them have been revealed in the Ten Commandments. Thomas's synthesis of natural and revealed knowledge, a goal sought by many other medieval thinkers, did not meet with wholehearted acceptance. In 1277 a number of Thomistic tenets were condemned by the bishop of Paris. Thomas met with a warmer reception in his own order, and in 1309 his doctrine was prescribed for the Dominicans. In 1323, Thomas was canonized, and since that time his thought has become more or less the official doctrine of the Roman Catholic church. He was declared a Doctor of the Church in 1567. In the 19th century, under Pope Leo XIII, the modern revival of Thomism began. Although uninspired adaptations of his thought have brought it into some disrepute, Thomas himself continues to be held in high esteem.