Aquinas, the towering medieval thinker, refused to call himself a philosopher
To medieval scholars, philosophers were pagans like Plato and Aristotle. Thomas Aquinas even complained that they fell short of true wisdom. Yet thinkers who saw philosophy as theology's handmaiden produced breakthroughs on time, universals and metaphysics, and one of them anticipated Descartes's famous I think, therefore I am by twelve centuries.
Independent philosophical inquiry in this era is usually traced to two starting points in the 8th century: Baghdad around its middle, and Charlemagne's travelling court at Aachen in its final quarter. Advised by Alcuin of York and others, Charlemagne decreed in 787 that every abbey in his empire should run a school. Those schools gave Scholasticism its name. By the mid-ninth century the library at Fleury was among the richest ever gathered in the West, drawing visiting scholars to consult it.
Two late Romans shaped everything that followed. Augustine, who lived from 354 to 430, was quoted in nearly every Latin work of theology or philosophy for over a thousand years; his remark that if he errs, he exists, foreshadowed Descartes. Boethius, consul in 510 under the Ostrogoths, set out to translate all of Plato and Aristotle into Latin. He managed several of Aristotle's logical works, and his commentary on Porphyry handed medieval readers the stubborn problem of universals.
Medieval work rested on three commitments: reasoning by logic and dialectic, deference to ancient authorities, above all Aristotle, and the duty to harmonise philosophy with revelation. The great quarrel was faith against reason. Avicenna and Averroes leaned toward reason, while the Augustinian formula, belief first and understanding afterwards, became the watchword of scholastics such as Albert the Great and Bonaventure. Anselm of Canterbury, who opened the high scholastic period, devised the ontological argument for God's existence.
The 13th century completed the recovery of Greek thought. Translators worked in Italy and Sicily; Adelard of Bath produced the first complete translation of Euclid's Elements, and William of Moerbeke's versions of Greek texts gave a clearer view of Aristotle than the Arabic intermediaries had allowed. Renaissance humanists later sneered at the whole era as a barbaric middle period, but modern historians see it as a time of genuine philosophical progress.
Source: Medieval philosophy
