St Thomas Aquinas (b. 1225, near Aquino, Sicily) was an Italian Dominican theologian whose scholarship propelled him to the first rank among the Scholastics of the Middle Ages. His major works are the Summa theologiae and the Summa contra gentiles. Thomas joined the Dominican order in his teens and was sent in 1245 to study at the University of Paris. His mentor there was Albertus Magnus (1206-80), a noted scholar during a time when the influx of Arabic-Aristotelian thought was arousing a sharp reaction among Christians. Some feared that Islam's appropriation of the ancient philosophers would somehow be used to prove a rational basis for Islam over Christianity. Others feared the influence of rationalism, especially the form advocated by the adherents of Averroes.
Taking up the work begun by Boethius, both Thomas and Albertus believed that philosophy could be used to strengthen religious conviction in general, and to vindicate Christianity in particular. The two men traveled to Cologne in 1248 and remained there for four years, studying and conducting classes. In 1252 the two returned to Paris so that Thomas could prepare for the master's degree. He obtained his degree in 1256 and began teaching that year. In 1259 he was appointed adviser and lecturer to the papal Curia. He remained in that position until 1268, and then returned to Paris to argue his position concerning the relation of faith and reason.
Like Augustine, Boethius, Rhazes, Averroes, Maimonides, and even the founder of Neoplatonism, Plotinus, Aquinas did not believe that philosophy and religion were in conflict. He went the furthest of them all, however, in attempting to delineate, in good Aristotelian fashion, the various categories that constitute the spiritual nature of man. Where Augustine relied on a Platonist notion of the abstract but perfectly real city of God versus the corrupt and sinful city of man, Aquinas, who otherwise accepted humankind's helplessness without God's active grace, attempted to show that man's imperfection and its relation to the divine could be understood and described rationally.
Ironically, some have argued, this very attempt placed religion and philosophy in even sharper contrast to each other. On the one hand, the tools of reason imply a definite power on the part of man to comprehend Creation; on the other hand, human imperfection denies that this is ultimately possible. This tension eventually worked to break asunder the delicate consensus over the mysterious union of free will in a divinely predestined universe, with some theologians favoring one or the other extreme, as exemplified in the later split between Luther and Erasmus. But these consequences were not Aquinas's intention. Indeed, the "neo"-Averroeists in the West, also taking their predecessor's positions to unintended extremes and contending that reason was faith, were the main focus of Thomas's opposition. Aquinas hoped to demonstrate that reason could work within faith but was not the same or superior. It was a delicate balance. In 1272, he established a Dominican house of studies at the University of Naples and defended the Aristotelian current of thought against the Franciscan scholar Bonaventure. Aquinas died on his way to the second Council of Lyons in 1274. He was canonized in 1323. His feast day is January 28.