Philosophy and Religion in Western Thought

The course of ancient speculation about divine matters was dramatically altered as early as the first century of the common era by the pagan world's contact with Judaism and subsequently Christianity. The intellectual directions of these faiths were also shaped as a result of coming into contact with ancient philosophy. In pagan thought, the contact produced a renewed interest in the representation of the divine nature. In Judaism and Christianity, it produced an energetic effort to present the claims of revelation in philosophically coherent ways. The renewed interest among the pagans is most evident in Neoplatonism, a school that included Plotinus (205–270), Porphyry (c. 234–c. 305), Iamblichus (c. 250–c. 330), and Proclus (410?–485). The new effort of speculation about divine matters can be seen, albeit in a different guise, in Jewish thinkers such as Philo Judaeus of Alexandria (first century C.E.) and among Christian thinkers such as Clement of Alexandria (150–between 211 and 215) and Origen (185?–254?). It led not only to philosophical explorations of Scripture but also to the development of a view within Christian circles that the "best" philosophy was to be found in Scripture.

After 400, philosophy became fully subsumed within the three monotheistic religions—Judaism, Christianity, and then Islam. Throughout the thousand years from the fifth to the fifteenth century, the largest part of speculative talent in the West was devoted to considering questions about the God of the Scriptures or revelation. Very few philosophers neglected the issues raised by the confrontation of ancient philosophy with the monotheistic religions, as can be observed in the writings of Arab thinkers such as al-Kindi (fl. ninth century), Avicenna (Ibn Sina; 980–1037), and Averroës (Ibn Rushd; 1126–1198).

In many Latin works the conversion or ascent of philosophy to faith is the central theme, as can be witnessed in the Confessions of St. Augustine of Hippo (354–430). For other late antique and early medieval thinkers, philosophy served as a prolegomenon to faith grasped and expressed as sacred doctrine (sacra doctrina). In Boethius's (c. 480–524) Consolation of Philosophy, the figure of philosophy reminds Boethius of verities without which his faith cannot be restored. One of the more enduring models of reflection on divine matters was presented by Anselm of Canterbury (1033 or 1034–1109) in his Proslogion. Building on the intellectual heritage of Augustine, he uses the phrase fides quaerens intellectum—faith seeking understanding. This strategy can clearly be seen at work in Anselm's so-called "ontological argument" in the Proslogion 2 and 54. It can be argued that one does much better justice to Anselm's intentions if one views the argument not as a demonstration of the existence of God but as a systematic investigation into God's mode of existence. As a person seeking understanding (fidelis quaerens intellectum), Anselm begins from a faith that provides the conceptual parameters of his philosophical reflection and then attempts to win his way through to a better understanding of the divine nature.

In terms loosely contiguous with Anselm's project, other medieval authors clarified the relation between philosophy and theology by insisting that philosophy must be studied thoroughly before proceeding to theology. Different examples of this tendency can be found in thinkers as diverse as the Christian Bonaventure (c. 1217–1274), in his Itinerarium, and the Jewish polymath Moses ben Maimon (Maimonides; 1135–1204). In a similar spirit, the Oxford philosopher and natural scientist Roger Bacon (c. 1220–1292) argued that nothing could be known about God without a prior study of languages, mathematics, optics, experiential science, and moral philosophy.

When arriving at the zenith of Scholastic speculation on God in the last quarter of the thirteenth and the first half of the fourteenth century, one finds a profound illustration of the range and diversity of the engagement of Christian theologians with the Aristotelian inheritance in the works of Thomas Aquinas (c. 1224–1274), John Duns Scotus (c. 1266–1308), and William of Ockham (c. 1285–?1349). For Aquinas, theology (theologia) employs, improves, and then perfects the best of ancient philosophy. He extended great deference to pagan philosophers, especially Aristotle, but whenever he spoke in his own voice he systematically transformed most of the Aristotelian doctrines he discussed, often in directions quite opposed to Aristotle's original intentions. Duns Scotus, on the other hand, began by candidly refusing to accommodate Aristotle, but what is called his "Augustinianism" is nothing but a mélange of the theological legacy from Augustine, the philosophical deposit of Neoplatonism, Scotus's reaction to the work of his contemporaries (in particular Henry of Ghent [c. 1217–1293]), and a model of Aristotelianism derived from reading Aristotle refracted through the glass of Latin Averroism. William of Ockham saw fit to repudiate some of the central features of the Aristotelianism espoused by his forebears, but he repeatedly sought to use Aristotle's work to support his own philosophical views and aspired to be perceived as a faithful Aristotelian.