Aristotle

   The importance of the newly rediscovered philosophical works of Plato in the literature and learning of the 15th and 16th centuries often causes students of the Renaissance to forget that the philosophy of Aristotle (384-322 B.C.), which had been rediscovered by the Latin West in the early 13th century and had become the philosophical basis for all study of philosophy and theology, remained dominant throughout the Renaissance. Plato may have been translated and frequently read; he (or his disciples, the Neoplatonists) may have had a powerful influence on poetry and other literary genres. But Plato was not taught—at least not formally and systematically. All philosophical instruction in the universities continued to be based on the logical method of Aristotle and also was influenced by other aspects of his philosophy. In particular, Aristotle, who was a great systematizer of ancient scientific knowledge, provided the only systematic body of well-organized knowledge and theory for the study of natural science. Not until the middle of the 17th century, when the work of Galileo Galilei, Johannes Kepler, and Isaac Newton made Aristotle's scientific works hopelessly obsolete and provided the basis for a whole new approach to the study of the natural world, was the stranglehold of Aristotle on systematic philosophy and science broken.

   The Latin Aristotelian texts taught in the universities were products of the Middle Ages, most of them translated in the 12th and early 13th centuries by Christian scholars who went to Spain and Sicily in order to find the manuscripts and to acquire the linguistic skills they needed. Nearly all of these medieval translations were based not on the Greek originals but on Arabic translations produced in the earlier Middle Ages. Although by the 13th century nearly all of the Aristotelian works now known had been made available in Latin, those translations were often defective. Renaissance scholars by the 15th century had become keenly aware of these defects. Once the Italian humanists had learned to read Greek, there was an effort to retranslate Aristotle directly from the Greek and to eliminate the ambiguities and errors of the traditional Latin texts.

   This push for better translations was led by some of the most influential humanists of the Quattrocento such as Leonardo Bruni, Ermolao Bárbaro, and Angelo Poliziano; and many new translations were made by émigré Greek scholars such as George of Trebizond and Johannes Argyropoulos. At the turn of the 16th century, the French humanist Lefèvre d'Etaples and several of his followers published new Latin editions of Aristotle for academic use, though many of the translations were the work of Italian and refugee Greek scholars during the preceding hundred years. This text-based reform of Aristotelianism in the long run proved hard for even the most conservative scholastic philosophers to resist, and during the early 16th century many of the new translations came into use.

   Renaissance Aristotelianism also produced new directions in the interpretation of Aristotle, in part because of the influence of ancient Greek commentaries that were now becoming available. There was a revival of interest in the interpretation of Aristotle given by the greatest Arabic philosopher of the Middle Ages, Averroës (in Arabic, ibn Rushd), who had already been known in the 13th century but had aroused much opposition because his interpretation of Aristotle clashed with Christian doctrine. The leaders in this revival were three professors at the University of Padua, Nicoletto Vernia (ca. 1420-1499), Agostino Nifo (ca. 1470-1538), and Marcantonio Zimara (ca. 1475-1532). The most controversial philosopher of the early 16th centry, Pietro Pomponazzi, was striving to reinterpret Aristotle when he wrote his famous treatise On the Immortality of the Soul. Even such important pioneers of the new science of the 17th century as William Harvey in medicine and Galileo Galilei in physics and astronomy began their scientific work as Aristotelians, though they (especially Galileo) took the steps that would destroy the authority of Aristotle as the guide to all scientific and philosophical questions.

   Just as the influence of Aristotle in most fields of study was waning, theorists of literature were rediscovering Aristotle's Poetics, a text that had been known but little regarded before 1500, and were making it the basis of a new literary aesthetic that was applied both to the composition of new literary works and to the critical evaluation of old ones. In English literature, both Sir Philip Sidney's Defense of Poesie and the preface to John Milton's Samson Agonistes represent an essentially Aristotelian philosophy of poetic composition.