People familiar with Thomas Aquinas's work know that he ranks among the greatest philosophers, but the number of such people is still smaller than it should be. Anthony Kenny described and gave one reason for this state of affairs more than a decade ago, when it was even more deplorable than it is now: 'Aquinas is little read nowadays by professional philosophers: he has received much less attention in philosophy departments, whether in the continental tradition or in the Anglo-American one, than lesser thinkers such as Berkeley or Hegel. He has, of course, been extensively studied in theological colleges and in the philosophy courses of ecclesiastical institutions; but ecclesiastical endorsement has itself damaged Aquinas's reputation with secular philosophers. . . . But since the Second Vatican Council [1962-65] Aquinas seems to have lost something of the pre-eminent favour he enjoyed in ecclesiastical circles. . . . This wind of ecclesiastical change may blow no harm to his reputation in secular circles.' (Kenny 1980a, pp. 27-28)

Today a somewhat prevalent impression links Aristotle and Aquinas as though they both represented the same general type of philosophical thinking. Prima facie indications, it is true, may seem to point in the direction of a unitary trend in their basic philosophical procedures. Aquinas uses Aristotle's formal logic. Both of them reason in terms of actuality and potentiality; of material, formal, efficient, and final causes; and of the division of scientific thought into the theoretical and the practical and productive. Both regard intellectual contemplation as the supreme goal of human striving. Both look upon free choice as the origin of moral action. Both clearly distinguish the material from the immaterial, sensation from intellection, the temporal from the eternal, the body from the soul. Both ground all naturally attainable human knowledge on external sensible things, instead of on sensations, ideas, or language. Both look upon cognition as a way of being in which percipient and thing perceived, knower and thing known, are one and the same in the actuality of the cognition.

For Aquinas metaphysics, first philosophy, and a philosophical science of the divine (scientia divina) are one and the same. Following Aristotle, he is convinced that there is a science that studies being as being. Like other theoretical sciences, metaphysics must have a given subject. According to Aquinas this subject is being in general [ens commune) or being as being. Aquinas describes this science in that way in order to distinguish it from the less extended and more restricted subjects of the other theoretical sciences - natural philosophy (which studies being as subject to change and motion) and mathematics (which studies being as quantified).

By emphasizing that the subject of metaphysics is being as being, Aquinas also establishes his position on an earlier controversy concerning the relationship between the science of being as being described by Aristotle in Metaphysics IV 1-2 and the “first philosophy” or “divine science” developed in Metaphysics VI 1. While the first approach emphasizes the nonparticularity of the subject matter of this science, the second seems rather to focus its study on one particular kind or range of being: separate and immaterial entity, or the divine. If Aristotle clearly attempted to identify these two as one and the same science at the end of Metaphysics VI1, not all interpreters believe that he succeeded.

Thomas Aquinas was born at the end of 1224 or the beginning of 1225 in Roccasecca, not far from Naples. He was the scion of a prominent noble family, the counts of Aquino. Aquinas received his earliest education at the Benedictine Abbey of Monte Cassino. In 1239 he went to the University of Naples to study the liberal arts.

In Naples Aquinas became acquainted with the relatively new Order of Friar Preachers, better known as the Dominicans. Like the Franciscans, whose order was founded during the same period, the Dominicans were mendicants, radicalizing the evangelical ideal of poverty. Unlike the Benedictines, the Dominicans did not tie themselves to one specific cloister. Their life was therefore marked by a high degree of mobility. The Dominicans were the first religious order to make devotion to study one of its mainobjectives;in keeping with this aim they established study houses in university cities throughout Europe. In 1244 Aquinas decided to join the new order, much against the will of his family, who apparently had other plans for him. He was detained for a year in the family castle of Roccasecca, but his family finally accepted Aquinas’s decision.

Aquinas wrote commentaries on five Old Testament books - Psalms, Job, Isaiah, Jeremiah, Lamentations; on two Gospels - Matthew and John; and on the Pauline epistles - Romans, I and II Corinthians, Galatians, Ephesians, Philippians, Colossians, I and II Thessalonians, I and II Timothy, Titus, Philemon, and Hebrews. The early catalogues of Aquinas's works also list a commentary on the Song of Songs, but no such commentary has been found. In addition, there are two inaugural lectures [principia) that are discussions of scriptural texts. The first inaugural lecture is based on a verse from Psalm 103: “ Watering the earth from above”;the second focuses on a division of the books of Scripture. Weisheipl argues that both these lectures were given in connection with Aquinas's inception as Master of Theology at Paris in 1256. Finally, Aquinas composed a continuous gloss on all four Gospels, the Catena aurea (Golden Chain). It consists in a compilation of relevant passages from the writings of the Greek and Latin Fathers of the Church.

Nothing occurs more spontaneously to the modern reader of Aquinas than to ask about the relations between his philosophy and his theology, and no question is more misleading. To ask how his philosophy is related to his theology supposes that he would admit to having two separate doctrines and that he would agree that a doctrine was his in any important sense. Aquinas was by vocation, training, and self-understanding an ordained teacher of an inherited theology. He would have been scandalized to hear himself described as an innovator in fundamental matters and more scandalized still to hear himself - or any Christian - called a “philosopher,”since this term often had a pejorative sense for thirteenth-century Latin authors. Still, there is certainly something to be queried in Aquinas's ample use of philosophical terms and texts, in his having commented meticulously on a dozen of Aristotle's works, and in his having been regarded by some of his contemporaries as too indebted to pagan thinkers. What, then, is the appropriate formulation of the modern reader's question?

Whether it be philosophical or theological in character, moral theory for Thomas Aquinas derives from reflection on actions performed by human agents. This truism calls attention to the priority of moral action over moral theory. Since human persons engaged in acting are aware of what they are doing and why, the distinction between theory and action is not one between knowledge and non-knowledge - between knowing and willing, say - but rather a distinction between two kinds of practical knowledge. In what follows I present a summary statement of Aquinas's moral philosophy, stressing the centrality of the analysis of human action to that theory and the way in which his doctrines of virtue and of natural law arise out of his theory of action. I end with a discussion of one topic central to the distinction between, and complementarity of, moral philosophy and moral theology: Have human persons two ultimate ends?

The work of Thomas Aquinas may be distinguished from that of many of his contemporaries by his attention to the writings of Moses Maimonides (1135-1204), a Jew, and Ibn Sina (Avicenna) (980- 1037), a Muslim. His contemporaries, especially in Paris, were responsive to the work of another Muslim, Ibn Rushd (Averroes) (1126-1198), for his rendition of the philosophical achievements of Aristotle, but Aquinas's relation to Averroes and to those who took their lead from him was far more ambivalent. Aquinas respected Rabbi Moses and Avicenna as fellow travelers in an arduous intellectual attempt to reconcile the horizons of philosophers of ancient Greece, notably Aristotle, with those reflecting a revelation originating in ancient Israel, articulated initially in the divinely inspired writings of Moses. So while Aquinas would consult “the Commentator” (Averroes) on matters of interpretation of the texts of Aristotle, that very aphorism suggested the limits of his reliance on the philosophical writings of Averroes, the qadi from Cordova. With Maimonides and Avicenna his relationship was more akin to that among interlocutors, and especially so with Rabbi Moses, whose extended dialectical conversation with his student Joseph in his Guide of the Perplexed closely matched Aquinas’s own project: that of using philosophical inquiry to articulate one's received faith, and in the process extending the horizons of that inquiry to include topics unsuspected by those lacking in divine revelation.

Introduction: mimesis and literary models

ALTHOUGH all medieval literature in the romance vernaculars may be characterized – even defined – as a sustained, dynamic response to the classical canon, Dante's Divina Commedia is an altogether exceptional case. For, in a variety of fundamental ways, the entire Commedia is built on a series of extended encounters with four Latin poets: Virgil, Statius, Lucan, and Ovid. The Commedia's plot line figures these encounters in four principal (and interrelated) manners: First, Dante-protagonist meets and interacts with all four poets, who are characters in his poem. Second, Dante-protagonist undergoes (and/or witnesses) a series of key experiences that are visibly modelled on narrative events from the Aeneid, the Thebaid, the Pharsalia, and the Metamorphoses. The most important, frequent, and systematic instances of this process involve two alternatives: either Dante-protagonist functions as a new, Christian Aeneas, modeled on the single protagonist of Virgil's epic; or he functions as a corrected version of one of the many protagonists of Ovid's multi-narrative epic.