Toward 1150 one of Abélard’s pupils, Peter Lombard, published a book which was at once a compilation of Abélard’s thought purified of heresy, and a beginning of the formal Scholastic philosophy. Peter, like Anselm, Arnold of Brescia, Bonaventura, and Thomas Aquinas, was an Italian who came to France for advanced work in theology and philosophy. He liked Abélard, and called the Sic et non his breviary; but also he wanted to be a bishop. His Sententiarum libri IV, or Four Books of Opinions, applied and chastened the method of the Sic et non: he drew up under each question of theology an array of Biblical and Patristic quotations for and against; but this Peter labored conscientiously to resolve all contradictions into orthodox conclusions. He was made bishop of Paris, and his book became for four centuries so favorite a text in theological courses that Roger Bacon reproved it for having displaced the Bible itself. More than 4000 theologians, including Albert and Thomas, are said to have written commentaries on theSentences.
As the Lombard’s book upheld the authority of the Scriptures and the Church against the claims of the individual reason, it stayed for half a century the advance of rationalism. But in that half century a strange event transformed theology. As the translation of Aristotle’s scientific and metaphysical works into Arabic had in the ninth century compelled Moslem thinkers to seek a reconciliation between Islamic doctrine and Greek philosophy; and as the impingement of Aristotle upon the Hebrew mind in Spain was in this twelfth century driving Ibn Daud and Maimonides to seek a harmony between Judaism and Hellenic thought; so the arrival of Aristotle’s works in Latin dress in the Europe of 1150–1250 impelled Catholic theologians to attempt a synthesis of Greek metaphysics and Christian theology. And as Aristotle seemed immune to scriptural authority, the theologians were forced to use the language and weapons of reason. How the Greek philosopher would have smiled to see so many world-shaking faiths pay homage to his thought!
But we must not exaggerate the influence of Greek thinkers in stimulating the efflorescence of philosophy in this period. The spread of education, the vitality of discussion and intellectual life in the schools and universities of the twelfth century, the stimulus of such men as Roscelin, William of Champeaux, Abélard, William of Conches, and John of Salisbury, the enlargement of horizons by the Crusades, the increasing acquaintance with Islamic life and thought in East and West—all these could have produced an Aquinas even if Aristotle had remained unknown; indeed the industry of Aquinas was due not to love of Aristotle but to fear of Averroës. Already in the twelfth century the Arabic and Jewish philosophers were influencing Christian thought in Spain. Al-Kindi, al-Farabi, al-Ghazali, Avicenna, Ibn Gabirol, Averroës, and Maimonides entered Latin Europe by the same doors that admitted Plato and Aristotle, Hippocrates and Galen, Euclid and Ptolemy.
Such an invasion by alien thought was a mental shock of the first order to the immature West. We need not wonder that it was met at first with an attempt at repression or delay; we must marvel rather at the astonishing feat of adaptation by which the old-new knowledge was absorbed into the new faith. The initial impact of Aristotle’s Physics and Metaphysics, and of Averroës’ commentaries, which reached Paris in the first decade of the thirteenth century, shook the orthodoxy of many students; and some scholars, like Amalric of Bène and David of Dinant, were moved to attack such basic doctrines of Christianity as creation, miracles, and personal immortality. The Church suspected that the seeping of Arabic-Greek thought into south France had loosened orthodoxy among the educated classes, and had weakened their will to control the Albigensian heresy. In 1210 a Church council at Paris condemned Amalric and David, and forbade the reading of Aristotle’s “metaphysics and natural philosophy,” or of “comments”—commentaries—thereon. As the prohibition was repeated by a papal legate in 1215 we may assume that the decree of 1210 had stimulated the reading of these otherwise forbidding works. The Fourth Council of the Lateran allowed the teaching of Aristotle’s works on logic and ethics, but proscribed the rest. In 1231 Gregory IX gave absolution to masters and scholars who had disobeyed these edicts, but he renewed the edicts “provisionally, until the books of the Philosopher had been examined and expurgated.” The three Parisian masters appointed to attend to this fumigation of Aristotle seem to have abandoned the task. The prohibitions were not long enforced, for in 1255 the Physics, Metaphysics, and other works of Aristotle were required reading at the University of Paris.19 In 1263 Urban IV restored the prohibitions; but apparently Thomas Aquinas assured him that Aristotle could be sterilized, and Urban did not press his vetoes. In 1366 the legates of Urban V at Paris required a thorough study of the works of Aristotle by all candidates for the arts degree.20
The dilemma presented to Latin Christendom in the first quarter of the thirteenth century constituted a major crisis in the history of the faith. The rage for the new philosophy was an intellectual fever that could hardly be controlled. The Church abandoned the effort; instead, she deployed her forces to surround and absorb the invaders. Her loyal monks studied this amazing Greek who had upset three religions. The Franciscans, though they preferred Augustine to Aristotle, welcomed Alexander of Hales, who made the first attempt to harmonize “the Philosopher” with Christianity. The Dominicans gave every encouragement to Albertus Magnus and Thomas Aquinas in the same enterprise; and when these three men had finished their work it seemed that Aristotle had been made safe for Christianity.