– T –

TALMUD. See TORAH.

TAULER, JOHANNES (1300–1361). Tauler was a Dominican who entered the order in Strassburg in 1315. Meister Eckhart had been lecturing there since 1312. Johannes followed him to Cologne around 1324 and was joined there by Heinrich Suso as a fellow student. Both were heavily influenced by Eckhart. It was at the studium generale (international house of studies) of the Dominicans in Cologne in 1326 that Eckhart was accused of heresy, so both Johannes and Heinrich lived through the experience of a master who went through an agonizing time. Eckhart died a year later, after submitting to the Holy See. Certain of his propositions, however, were condemned shortly after his death by Pope John XXII.

This troublesome experience is not visible in the writings of Tauler. Tauler’s sermons, simple and direct, were usually delivered to Dominican nuns in the Rheinland. They have a commonsense character to them, urging the proper blend of the contemplative and the active life. In the life of activity he praises those who share what they have received in prayer and silence. He is certainly critical of those who are excessively anxious, but, in contrast to the Brethren of the Common Life, he encourages the activity that reveals the riches given by God in the quiet of contemplation. He also preached a welcoming attitude toward suffering, encouraging his audience to join their sufferings to the suffering of Christ, thereby helping him to carry his cross to Calgary.

TEMPIER, ÉTIENNE (d. 1279). A native of Orléans, Tempier became chancellor of the University of Paris in 1263 and Bishop of Paris in 1268. He is best known for his condemnations in 1270 and 1277 of philosophical propositions being debated at the university. Certain Aristotelian and Averroist tenets had come to be seen by many as incompatible with Christian doctrine. Already in 1210, 1215, and 1231, the teaching of certain Aristotelian works had been prohibited by the bishop, the cardinal, and the pope respectively. Before 1240, William of Auvergne criticized Aristotle and Avicenna on a number of points. In 1267, Bonaventure in the same vein protested against Averroists. Tempier, in 10 December 1270, condemned 13 propositions, most of which explicitly or implicitly espoused monopsychism (the doctrine that there is one intellect for all humans), the necessity of events, the eternity of the world, and limitations on God’s power. Paris was the leading theological center in Christendom and thus developments at the university were very important to the new pope, John XXI (elected in 1276), who had taught at Paris and, as Peter of Spain, written an important logic textbook.

Tempier’s great condemnation took place 7 March 1277, when he condemned 219 propositions. (Soon thereafter the Dominican friar, Robert Kilwardby, Archbishop of Canterbury and former theologian at Paris, condemned 30 propositions.) Most of the propositions were associated with doctrines held by masters and students at the Arts Faculty, such as Siger of Brabant and Boethius of Dacia, and were reflective of the influence of Aristotle and Averroes, in regard to, for example, the role of philosophy, the eternity of the world, necessity in regard to God’s act of creation, and the unity of intellect. Some doctrines held by Thomas Aquinas, mainly on individuation by matter and on the relation between the intellect and the will, were also included (though these propositions as Thomas understood them were removed from the list after his canonization in 1325). For Thomas’s disciple Giles of Rome, the condemnation meant an eight-year suspension from the university. Henry of Ghent played an important role in formulating certain theses of the 1277 condemnation, even ones associated with Aquinas, mainly, concerning individuation by matter and the relation of intellect and will.

This great condemnation had a profound influence on the development of medieval thought, but its full significance is still being debated. It is certainly a significant landmark in the developing relation between Augustinianism and Aristotelianism in Christian thought. Although the condemnation seems to point to the victory of the former over the latter, Aristotle continued to flourish thereafter, even among Augustinians who ever more critically appropriated and used Aristotle within their theologies. The condemnation ushered in a much more critical period of synthesis and analysis. Its influence is seen in later writings, which refer to the condemned propositions as the “Parisian articles.”

THEOLOGY. The term “theology” in the Latin West was set aside by St. Augustine in his De civitate Dei, since he criticized the association it had in the ancient world. Varro had spoken of three types of theology: one portraying the gods of the poets; a second defending the gods of the philosophers; and a third supporting the gods of the city. Since Christians rejected each of these senses of “theology,” Augustine avoided the expression. Peter Abelard resurrected the term in the 12th century and gave it a Christian understanding as he referred to the study of a number of Christian truths as “our theology.” Around the same time, Hugh of Saint-Victor mentions “theology,” and explains the meaning of its nominal definition. A major change took place in the mid-13th century when Christian teachers realized that Aristotle had spoken of his first philosophy or metaphysics as “theological.” They took up the challenge to produce a Christian version of the primary science and likewise called it theology.

The meanings of the word “theology” vary among the different medieval Latin authors. For them, theology sometimes is a synonym for “sacred Scripture”; at other times, it means some form of logically ordered study of all things as the Scriptures represent them. In its ideal, theology attempts to see all reality according to the way God sees it and has revealed it to men in the sacred Scriptures. The prologues of all the Commentaries on the Sentences and Summae theologiae try to describe their author’s view of what exactly theology is and does.

THIERRY OF CHARTRES (ca. 1100–ca. 1155). Possibly a brother of Bernard of Chartres, this theologian learned in liberal arts (most of the philosophy and science at the time), first taught at Chartres and then at Paris (where John Salisbury and Clarembald of Arras studied under him) before succeeding Gilbert of Poitiers in 1141 as chancellor of Chartres. A native of Brittany, he possibly participated in 1121 at the Council of Soissons, which condemned Peter Abelard, in which case he would be the Thierry mentioned in Abelard’s History of My Calamities. He participated in the Council of Rheims in 1148, which deemed heretical certain Trinitarian views of his predecessor Gilbert, and served as archdeacon at Dreux. In a Platonic vein, he speaks of God as the transcendent, simple One or Unity, from which all beings derive their formal unity. He also ascribes to the human soul an intellectual capacity for direct mystical vision of God.

Aside from his wide recognition among contemporaries as a prominent Platonist and liberal arts master, Thierry’s fame in intellectual history comes primarily for his original use of the arts and science in theology. Drawing from Chalcidius’s translation of Plato’s Timaeus, his Tractatus de sex dierum operibus [Treatise on the Works of the Six Days of Creation] uses mathematics to prove God’s existence and triune nature, and provides a physical interpretation of the literal text of Genesis that relies on mechanistic explanations of motion. This mechanism is noteworthy considering his ignorance of Aristotle’s Physics. His other works include glosses on Boethius’s theological works and on Cicero’s De inventione [On Rhetoric] and his Heptateuchus [Seven Branches of the Mathematical Arts], a work that discusses the liberal arts as the only path to wisdom.

THOMAS AQUINAS (1225–1274). The most famous of the medieval Christian philosophers and theologians, Aquinas was born into a noble family in Rocca Secca in the kingdom of Naples, around 1225. He began his education at the Benedictine monastery of Monte Cassino, but the abbot soon decided that he was worthy of higher challenges and sent him to the new University of Naples in 1239. He studied the liberal arts there under Peter of Ireland and sometime between 1240 and 1243 he joined the Dominicans. His family was unhappy with this decision and kept him from following this vocation by incarcerating him for a time, before finally relenting and allowing him to go to Rome and then to Cologne, where he began in 1244 or 1245 his studies with Albert the Great. In 1245, Thomas went with Albert to Paris, staying there with him until both returned to the new studium generate (international house of studies) at Cologne in 1248. In the early 1250s, he was ordained a priest and also commented on the Sentences of Peter Lombard. Because of turmoil at the University of Paris, he was not able to become regent master until 1257. His whole life was dedicated to teaching and writing, giving his services at various Dominican studia: Anagni, Rome, Bologna, Orvieto, Perugia, Paris, and Naples. He died on his way to the Council of Lyons in 1274.

The number and diversity of Aquinas’s writings is very impressive. His commentaries on the works of Aristotle reveal an extensive and deep understanding of the logical treatises, such as the Perihermeneias [On Interpretation] and the chief work dealing with the nature of science, the Posterior Analytics. In regard to the more properly philosophical works, he studied both the theoretical and practical aspects of Aristotle’s philosophy. In the theoretical realm, he commented in detail on Physics, On the Heavens, On Meteorology, and Metaphysics. In the practical areas of Aristotle’s philosophy, he wrote a lengthy commentary on the Nicomachean Ethics and on the first part of the Politics. He spoke in such depth and detail in his Aristotelian commentaries that he was not able to finish some of them, and they had to be completed by others, as is the case, for example, with the Politics, which was completed by Peter of Auvergne.

Thomas also left behind a large collection of Scripture commentaries: a long Literal Commentary on Job, and Lectures on the Gospel of Saint John and on many Pauline epistles (Ephesians, Galatians, Hebrews, Philippians, and Thessalonians). He also gathered an extensive Catena aurea: a commentary on the four Gospels collected from the works of the Fathers of the Church. His basic portrait of theology can be found in his Compendium theologiae [Compendium of Theology], but it is little more than an outline in comparison to his two summae: the Summa theologiae [Summa of Theology] and his Summa contra Gentiles [On the Truth of the Catholic Faith]. The Summa theologiae is his substitute for a commentary on the Sentences of Peter Lombard. Thomas, in fact, wrote a Commentary on the Sentences, and even tried to do so a second time. He gave up, finding Peter Lombard’s work repetitious, not well-ordered enough, and plagued by a series of useless questions. As a master, Aquinas also debated in 12 quodlibet disputations and in an impressive number of specific Disputed Questions: On Virtues, On Truth, On God’s Power, On Evil, On Spiritual Creatures, On the Incarnate Word, On Hope, and On Fraternal Correction. He also wrote commentaries on two of Boethius’s theological tractates: On the Hebdomads and On the Trinity. He also produced a collection of smaller philosophical and theological treatises, sermons, and letters.

Aquinas took philosophy more seriously than anyone else, even more seriously than the Averroists. When he argued with them, his main point was that philosophy is not knowing what Aristotle or Averroes said. Philosophy is using reason to know the way things are. It is not principally a study of texts; it is a study of reality. As he dealt with some of the main concerns in the Arts Faculty, the eternity of the world or the unicity of the intellect, Thomas was not satisfied to say that a philosophical authority was wrong. He made the effort to show why on his own terms of using reason alone he was wrong, if it were possible to do so. At times, he might admit that he could not prove philosophically that a position contrary to the revelation of Scripture was wrong. Yet, his philosophical efforts bore fruit. He made the radical or Averroistic Aristotelian Siger of Brabant change his position on philosophical grounds, especially in regard to the unicity of the intellect. Thomas’s philosophical positions also got him into difficulties with Church authorities, as can be seen when some of the 219 propositions included in the Condemnation of 1277 are examined. Some propositions that relate to him are also included.

In theology, Aquinas’s Summa theologiae is considered one of the great treatises in the history of Christian theology. He attempted in this work to make the human effort to try to see things theologically, that is, according to the divine order of reality. That is why he speaks of theology as a subordinated science, an ideal portrayal of reality achieved in subordination to God’s knowledge and revelation, and an ideal that is fulfilled only in the enjoyment experienced in the vision of the blessed. For Aquinas, the great synthetic work of Peter Lombard, for all its achievements, had fallen short: unimportant issues received more attention than they deserved and the ordering at times seemed subordinated to the contingent order of the individual passages of Scripture rather than to the wisdom of God revealed in its whole message.

In organizing a science of theology, that is, trying to map out what we can know of God and his relation to everything else, Thomas had to find a starting point or set of principles for his science. He found them in the Church’s digest of the main points of the teaching of the Scriptures, in the Creed. Beginning with the Creed, which provided him with the principal points of God’s revelation, he could go, and actually did go, in two directions. He could draw out or deduce further specific teachings of the Scriptures. He could also focus on the articles of the Creed themselves and try to bring a deeper understanding to these main truths of the Christian faith.

In the first approach, that of deductive theology, he was effectively attempting to show how all the elements of theology, the principles, and the further conclusions held together or formed a cohesive unit. Such an effort was the human attempt to see God’s order of things. The second procedure, declarative theology, centered attention principally on the articles of the faith, and tried to bring a clearer understanding of them. A theologian like Thomas could do this by focusing on the doctrine of the Trinity, for example, and with the help of the Scriptures and the Fathers of the Church attempt to find the language that best expresses this doctrine of three persons in the one God. The traditional patristic language spoke of persons and essence. What is meant by “person?” Do we have a definition of person that can be applied to God? What is that definition? Is it a good one or can we get one that brings better understanding? The same holds for “essence.” How is the essence of a person different from what makes a person a person?

In trying to bring understanding to an article of the faith, such as the Trinity, Thomas could and did look at the long tradition of theological attempts to bring understanding. He could search patristic works for analogies that might help. There are many books on the Trinity, the De Trinitate of St. Ambrose, the De Trinitate of St. Augustine, the De Trinitate of Boethius, and the De Trinitate of Richard of Saint-Victor. Which of these works presents the best analogies that might help us understand somewhat this mystery of the faith?

Another source for bringing understanding that Aquinas used to great positive effect is the examination of heresies. At first sight, heresies might seem to provide negative feedback, but this is far from the case. The defenses against heresies in the Christian tradition have been a great positive source for understanding, since often in refuting heresies, the Fathers of the Church had to explain why the heretical position was wrong. Aquinas especially shows the positive understanding that comes from defending the faith against heresies in his Lectures on the Gospel of Saint John and the Catena aurea where he examines all the heresies related to the Trinity and the Incarnation of Christ as Son of God.

In developing his theological treatises, Aquinas in his deductive theology is following the course the Church has followed in making the basic truths of the Christian faith more explicit by deducing or leading out what is implicit in the Scriptures and earlier Church credal statements. In practicing declarative theology, he followed the lead of St. Augustine, who in the opening chapter of Book XIV of the De Trinitate, urged Christians to pursue the kind of knowledge by which “our most wholesome faith . . . is begotten, nourished, strengthened and defended.”

THOMAS BRADWARDINE. See BRADWARDINE, THOMAS (ca. 1290–1349).

THOMAS GALLUS (ca. 1200–1246). Thomas became a canon regular of St. Augustine at the monastery of Saint-Victor, and later assisted in the founding of the Victorine abbey and hospital of Saint-Andrea in Vercelli. He became its first prior and later its first abbot. Most of his writings were done there. His writings are well catalogued, since he provides very helpful information in them that allows for their dating and place of composition. His Commentary on Isaiah was completed at Saint-Victor in 1218. A bit earlier he had already made a chart providing the divisions and subdivisions of the works of Dionysius the Pseudo-Areopagite, so he had even at this early time a basic sense of how he would write his commentaries on the Scriptures and on the Dionysian corpus. His commentaries on the Song of Songs stretched out over most of his adult life. The first, now lost, was completed at Vercelli around 1224. A second, incomplete commentary was done either at Vercelli or when he was visiting Chesterton in England, in 1237–1338. The third commentary was done while he was in exile in Ivrée in 1243.

While at Vercelli in 1224, Thomas followed up on the outlines he had made of Dionysius’s works with short glosses on two of them, the Celestial Hierarchy and Mystical Theology. Next he made Extractiones [Extracts] of all of Dionysius’s works. These extracts were neither paraphrases, nor commentaries, nor translations properly speaking; they provided a more understandable text than the ones offered by the translations of Saracen or John Scotus Eriugena by abridging the text, giving a short paraphrase, or leaving aside secondary ideas. Some medievals, for example, Francis of Meyronnes, treated these extracts as though they were a new translation. Thomas also made in his later years (1241–1244) Expositions or Explanations of all four works of Dionysius: Mystical Theology, Divine Names, Angelic or Celestial Hierarchy, and Ecclesiastical Hierarchy. In these grand-scale commentaries, he explains each word or expression in a few lines, supporting his explanation with citations from the Scriptures and other Dionysian works. Thomas’s purpose in all his treatises is to fulfill the words of the prophet Jeremiah 9:24: “Let him who will glory glory in this: to come to a knowledge of (scire) and really to know (nosse) me.” For Gallus, we come to a knowledge of (scire) God, when we know God through the contemplation of creatures, or the teachings of men, or personal reflection of a rational or intellectual kind. This is the kind of divine knowledge gained by the philosophers. But we come really to know (nosse) God when we know him in a way that is incomparably deeper. This is a knowledge that he describes as supraintellectual in the way that it is associated with affectus [love] and thus transcends the philosophical intellect in the way that the philosophical intellect transcends reason, and reason transcends imagination.

THOMAS OF ERFURT (fl. ca. 1300). Like the earlier Martin of Dacia, Thomas is one of the principal authors of speculative grammar. Grammar was taught at a different level in the Arts Faculty than in preuniversity courses. In the Arts Faculty, one studied Priscian’s Institutiones grammaticae [Grammatical Foundations], but, as in other fields, such as logic or dialectics, from a careful reading or lectio questions developed. Later, at a more advanced level, disputations regarding the issues raised by the questions followed. These methodical developments led in the area of grammar to treatises called De modis significandi [On the Modes of Signifying]. Among the best known treatises of this kind are the works of Martin of Dacia and Thomas of Erfurt (whose treatise was long published under the works of John Duns Scotus). Thomas’s work was probably written at Paris around the end of the 13th century. Eventually, these university materials were digested and were filtered down into basic grammar courses. A text that shows this is John of Cornwall’s Speculum [Mirror], whose technical terminology seems to depend more on Thomas of Erfurt than Martin of Dacia.

THOMAS OF STRASSBURG (ca. 1275–1357). Thomas already had completed his liberal arts and theology studies when he joined the Hermits of St. Augustine. We know he taught at Strassburg from about 1330 to 1345. His Commentary on the Sentences, the first by an Augustinian on all four books of the Sentences, probably dates from 1335–1337. He was elected general prior in 1345, and held this office until his death in 1357. Thomas still followed the tradition of his fellow Augustinian Hermit Giles of Rome, staying close to the teachings of Thomas Aquinas. Later Augustinian Hermits, for example, Gregory of Rimini, pursued a new direction, more related to Oxford theology.

THOMAS OF YORK (ca. 1210–ca. 1260). Prior to his appointment as the sixth master of the Franciscan studium at Cambridge, Thomas was master in theology at Oxford from 1253–1256. Concerning central issues, such as his theory of knowledge and the relation between philosophy and theology, he follows the Augustinian tradition of Bonaventure rather than Thomas Aquinas’s Aristotelianism. However, his style is rather synthetic and conciliatory, as reflected by his encyclopedic work Sapientiale [A Wisdom Collection] that is made up of seven books. It carefully recognizes a great variety of sources from philosophical and theological traditions, including Jewish and Islamic ones, and tends to bring them together harmoniously in relation to different questions. If Manus quae contra omnipotentem [The Hand Raised against the Omnipotent God] is correctly attributed to Thomas, he wrote in favor of the mendicant orders against seculars, such as William of Saint-Amour.

THOMAS SUTTON (ca. 1250–ca. 1315). Thomas was born near Lincoln. He was a socius at Merton College and his study of the liberal arts gave him a predilection for a pure Aristotle. He was ordained a deacon by Walter Giffard, the Bishop of York in 1274. In 1282, he joined the Dominicans and became regent master about 1285. Probably he was a master of theology from 1290 until about 1300, but there are signs that he was still teaching up to 1315. He was considered very Thomistic in his teachings and some of his writings were so close in their teachings to the positions of Thomas Aquinas that they were considered to be authentic works of Aquinas himself. Sutton was an early defender of Aquinas, especially concerning metaphysics and epistemology, against the alternative projects of Henry of Ghent and Duns Scotus. He defended the doctrine, held by Aquinas, that there is only one substantial form in composite beings in his treatises Contra pluralitatem formarum (Against the Plurality of Forms), De productione formae substantiarum [On the Production of the Form of Substances], and in his question Utrum forma fiat ex aliquo [Whether the Form Comes into Existence from Something]. Among other works, he completed some of Aquinas’s commentaries on Aristotle, namely his Perihermenias [On Interpretation], De generatione et corruptione [On Generation and Corruption], and Quaestiones super librum sextum metaphysicorum [Questions on Book VI of the Metaphysics]. In addition, he composed four quodlibeta and 36 disputed questions. His first two quodlibeta are dated after 1287, since they quote certain later works of Henry of Ghent. His references to Duns Scotus place his last two quodlibeta and questions 27–35 of his disputed questions in the early 14th century.

THOMAS WYLTON (WILTON) (ca. 1265–1327). This secular priest received his master of arts at Oxford and was a fellow of Merton College from 1288–1301. He was granted permission to study theology in England or elsewhere in 1304. He chose Paris, since we know that he taught as a bachelor of theology at Paris in 1311. Thomas was master of theology there from 1312–1322, and counted Walter Burley as one of his students. Burley also is an author with whom he often argued. Very independent in his thinking, Wylton was at times influenced by John Duns Scotus. This is especially noticeable in his quodlibet, probably disputed around 1315, where he explains in a very detailed way Scotus’s formal distinction in the context of his discussion of the divine attributes. He left Paris in 1322 to become chancellor of St. Paul’s in London, a position he held until his death in 1327.

THOMISM. The term “Thomistic” might refer to a particular teaching of Thomas Aquinas or to the Thomistic school of philosophy and theology that is named after him. In the latter sense, “school” might be multiplied, since historians speak of the early Thomistic school at Oxford or the early Thomistic school of Paris. Some of Aquinas’s philosophical and theological positions were attacked even in the 13th century. He was one of the focuses of the Condemnation of 1277 at Paris, which was extended to Oxford by Robert Kilwardby, himself a Dominican like Aquinas. Thomas was, however, mostly attacked in Oxford by Franciscans. Among the early Thomists at Oxford were those who came to his defense: Robert of Orford, Richard Knapwell, and Thomas Sutton. Aquinas’s chief opponent at Paris quite likely was Henry of Ghent. Early Parisian Thomists who attempted to respond to various challenges from Henry were John of Paris and William Peter of Godino. In the next generation the leading Thomist was Hervaeus Natalis, who was the chief force in the effort to have Thomas canonized. More famous later Thomists were John Capreolus (d. 1444), called “The Prince of the Thomists,” and Thomas de Vio or Cardinal Cajetan (d. 1534), renowned for his commentary on the Summa theologiae, and Sylvester of Ferrara (d. 1528), the famous commentator for the Summa contra Gentiles. The 20th century also had well-known Thomistic theologians, such as Reginald Garrigou-Lagrange, and respected historians of Thomistic philosophy, such as Étienne Gilson.

TORAH. As a term, “Torah” comes from the Hebrew root yaroh, which means “to teach.” As an entity, the Torah is the sacred revelation of the Jews, their holy teaching. Though Torah is commonly translated as “law,” the teaching of the Torah goes far beyond purely legal matters. According to the Jewish tradition, the prophet Moses received from God both the written law (the Pentateuch) and the oral law, passed on through the rabbinic tradition and viewed as necessary for the proper understanding of the written law. Thus, as a term, Torah can mean not only the Pentateuch but the whole scriptural tradition. This includes the 24 books of the Hebrew Bible and their commentaries, as well as the oral legal tradition embodied in the Talmud. The Talmud includes the Mishnah, codified in the second century C.E., and the Gemara, which elaborates and comments on the Mishnah from the second to the sixth centuries. Karaite Jews, who rejected the rabbinic tradition and accepted only the written text of the Bible as authoritative, are the exception to those accepting this broader sense of the Torah.

TRANSUBSTANTIATION. See EUCHARIST.

TRINITY (TRINITARIAN DOCTRINE). The Trinity and the Incarnation constitute the two fundamental truths of Christianity. The central Christian teaching about God is that he is triune, and the traditional formula is one God in three persons, the Father, the Son, and the Holy Spirit. Its basis is found in revelation, in both the Old and New Testaments, especially in St. John’s Gospel and in the writings of St. Paul. The Trinity did not become an officially declared doctrine of the Church until the fourth century. Questions about the divinity of God’s Word, incarnate in Jesus, and of God’s Spirit, prompted the Church to elaborate an official doctrine about God that also served as the criterion for heresies. Sabellianism, initiated by Sabellius in the third century, and Arianism, initiated by Arius (ca. 256–ca. 336), were then the two most significant heresies. Sabellianism asserted that the three persons are only modes or aspects of God, without being really distinct persons, while Arianism stated that the Father, who alone is God, is a different being from the creatures that come from him, the first creature being the Son.

In its first ecumenical council, the First Council of Nicea (325), the Father and the Son were officially identified as God. The three persons were explicitly declared to be three divine persons in the creed of the First Council of Constantinople (381) (the “Nicene Creed”), after theological reflections by Athanasius and the Cappadocian Fathers, portraying them as distinct divine persons according to origin or procession. The Latin or Catholic Church’s official Filioque doctrine, that the Holy Spirit proceeds from both the Father and the Son, and not from the former only, as is taught by the Eastern Orthodox Church, was added to the Nicene Creed in the sixth century, chiefly due to Augustine’s influential teaching. The popes resisted the official inclusion of the Filioque until the 11th century, although Charlemagne wanted to impose it on the whole church back in the late eighth century.

Medieval Christian theologians provided accounts of the Trinity. Though they generally treated the Trinity as a revealed article of faith, not subject to demonstration, they still sought to clarify this belief, their central tenet about God. In so doing, they drew from the various areas of learning, especially philosophy. Anselm, Peter Abelard, Peter Lombard, and Gilbert of Poitiers are well known for their use of dialectics in Trinitarian speculation, while others distinguish themselves through their use of other branches of learning, particularly metaphysics. Some of the most elaborate philosophical treatments in medieval thought, which is fundamentally God oriented, are found in Trinitarian discussions. What follows is a brief statement of salient points in the tradition of Trinitarian speculation.

Medieval Christian thinkers generally agree with Aristotle’s view that God is essentially mind, thought thinking itself, and they stress that God’s thinking also includes willing or love. However, they disagree with Aristotle because for them the First Cause is not merely a final cause of the world, but also an efficient cause, the Creator of the world. In turn, they agree with the father of Neoplatonism, Plotinus, who holds that God is the One from which all emanates. However, they disagree with Plotinus because for them the One is not beyond being but rather is the highest and transcendent being. Moreover, for them the One is not absolutely one, because the first emanations of the One, namely the Son and the Holy Spirit, are not transitive but immanent to the One.

Despite these disagreements with Plotinus, most Christian thinkers, some to a larger extent than others, have derived inspiration from the Neoplatonic tradition when speculating about the Trinity. For example, Dionysius the Pseudo-Areopagite, Bonaventure, Richard of Saint-Victor, and Henry of Ghent draw from Plato’s Timaeus and take it one step further. Whereas Plato describes the Good as diffusive of itself toward the created world, they understand the Good as an essentially self-diffusive Love. Since love or charity is the most perfect goodness, and love is by nature diffusive of itself, then God, who is the most perfect Love, must be essentially self-diffusive. His first act of diffusion cannot be transitive or creative, which would be an imperfect diffusion, created goodness being less perfect than Love or God himself. Rather, God’s first self-diffusion, as most perfect, must be constitutive of and identical with himself: a most perfect self-communication in one singularity of essence, whereby that which receives what is given and that which gives it share the same singular nature. However, since God is mind, rationally distinguished into intellect and will, there are two emanations within the Godhead and three consubstantial persons. Thus, the Son is the Word generated by the divine intellect or Father, and the Holy Spirit is the love between the Father and Son. Through these emanations, God communicates himself to himself, by knowing and loving himself. But how can these tenets be understood in a way that elucidates God’s triune nature?

Aristotle, through his categories of substance and relation, is also present in medieval speculation on the Trinity. Relation, which is not an absolute thing but a circumstance of an absolute thing, can explain how God is one substance in three distinct persons, the official Christian position. For example, the Father is the divine substance as related to and distinct from the Son, who is this same substance as related to and distinct from the Father. Thus, there is substantial unity and relative or personal plurality in God: the heresies of Sabellius (the divine persons are distinct only nominally) and of Arius (the Son and the Holy Spirit are creatures because they are not substantially one with the Father) can be avoided.

Most medieval Christian theologians, whether of a more Aristotelian or Neoplatonic inspiration, grant the two immanent emanations, as well as the relations, of the Trinity. However, even though they see the Trinity in itself as eternal and necessary, the question for them still is: What is the right conception of the ultimate reason for God being triune? Is it emanation or is it relation? For example, one may ask of the Father: Is he the Father because he generates or does he generate because he is the Father? These are two chief Latin accounts of the Trinity received by thinkers in the latter half of the 13th century: the relations account originated by Augustine (354–430) and Boethius (ca. 480–ca. 525) in their respective treatises De Trinitate, and developed by Thomas Aquinas (influenced by his teacher Albert the Great), and the emanation account originated in the 12th century by Richard of Saint-Victor (influenced by his teacher Hugh of Saint-Victor), and developed by Bonaventure. For Thomas Aquinas, the Father generates because he is Father; relation accounts for the subsistence of the Father, which relative subsistence is presupposed by the Father’s proper activity of generating. For Bonaventure, the Father is Father because he generates; generation accounts for, and thus is rationally prior to, the Father’s relative subsistence as Father. In turn, Giles of Rome’s account modifies St. Thomas’s. Finally, Henry of Ghent, though more in line with Bonaventure’s tradition, is rather innovative in his development of both traditions and, especially, in his use of Augustine’s psychology of the Trinity. For Henry, the ultimate reason why the persons are distinct is not emanation or relation (though he grants the reality of both), but the divine nature’s intellectual and willing dimensions.

These 13th-century positions are then developed variously. Duns Scotus developed many of his positions against the background of Henry of Ghent and drew, among others, from the Victorines and his fellow Franciscan Bonaventure. Scotus produced many immediate followers, such as Peter Aureoli and William of Ockham. His influence was still strong at the Council of Trent (1545–1563), where roughly one-half of the representatives were Scotists. Thomas Aquinas also generated many medieval followers, such as Ulrich of Strassburg and Godfrey of Fontaines. Meister Eckhart (1260–1328) and Nicholas of Cusa in the 15th century provided accounts that synthesize the Aristotelian tradition of Aquinas and the Neoplatonic tradition of Henry of Ghent and Bonaventure.

TRIVIUM. See LIBERAL ARTS.