Category: Persons

Thomas Aquinas

One of the most important philosophers of the Middle Ages (1224/25-1274), Dominican friar and a leading theologian of the Roman Catholic Church, is considered to have accomplished a synthesis of the Christian thought and revelation with the Aristotelian philosophy and set up a rigidly structured theological system and a kind of Christian philosophy. The presence and influence of Platonic philosophy and tradition can be traced in his manifold and vast work.

Life and Work

Thomas was born in 1224/25 in the castle of Roccasecca, between Rome and Naples, into a feudal noble family of Aquino. From his early age he entered in the Abbey of Monte Cassino and studied theology and philosophy. He joined the recently set-up Order of Dominican Friars, and continued his studies in Naples, Paris and Cologne, next to Albert the Great, who introduced him to Dionysius Areopagite. He stayed in Paris (1252-1259), where he received his Master (Magister) of theology; after returning to Italy (1259-1268) and during his stay in Paris (1268-72) and Naples he did not stop to teach and write. He died of illness on his way to Lyons to participate there into a Synod for the Church union.

Thomas is perhaps the most prolific medieval writer; his entire work is is estimated at around eight million words, something even more impressive considering that essentially it was written between 1256 and 1274. It includes the great theological compositions Scripta super libros Sententiarum (Writings on the Books of Sentences [of Peter Lombard], circa 1256), Summa contra Gentiles, (Summary Against the Heathens, 1261-63), and Summa theologiae (Summary of Theology, 1265-73); academic issues on various topics (Quastiones disputate and quodlibetalis) and special treatises, commentaries in thirteen books of the Bible and other “Neoplatonic” writers (such as Boethius and Dionysius Areopagite), polemic works against Averroists and others, as well as other categories of works. Of particular interest for medieval philosophy are his commentaries on twelve works of Aristotle.

Thomas consistently and steadily, from his early commentary on Peter Lombard to his mature writings, opens dialogue to each and every thinker and text at his disposal. This is attested by tens of thousands of references to Christian (Augustine, Gregory the Great, Dionysius Areopagite, John Chrysostom, John of Damascus), Arab (Averroes) and ancient Greek (Aristotle) authors.

In his times Thomas was renowned mainly among Dominicans; some of his views were condemned in 1277 by the bishop of Paris. His works were translated into Greek and influenced the later Byzantine theology. Later (1567) he was proclaimed Doctor Ecclesiae and in the First Vatican Synod (1879) at the instigation of Pope Leo XIII he was established as the true philosopher par excellence; Thomism became the official philosophy of Roman Catholicism as a response to modern thinking and his work came at the heart of philosophical inquiry. A more recent philosophical papal circular (Fides et ratio [Faith and reason] 1998) reaffirmed its importance as a pillar of Christian philosophy. His thought is broadly discussed and examined and still has a considerable impact in many fields (besides theology) such as philosophy of religion, metaphysics, ethics and philosophy of law. Thomas remains the most famous philosopher of the medieval period.

Thomas’ attitude to philosophy

Aquinas makes a step away from the highest authority of the Fathers of the Latin Church, Augustine, and turns to Aristotle. Aristotle's work has already become known through its interpretation by Arabs philosophers and at the thirteenth century is being translated directly from the ancient Greek –something that allows for an interpretation of his thought nearer to the texts, without the filter of interpretation of Averroes or Avicenna. Thus a form of 'Aristotelian Christianity' begins to emerge against the so-called Christian Platonism, the Augustinian tradition. The theology of Thomas is clearly influenced by the systematic character and some basic philosophical views of Aristotle.

In Paris, where Averroism prevailed, Aquinas tries to provide his own answer not only to fundamental theological-doctrinal issues but also to questions about the nature and the limits of non-theological knowledge. While he accepts the Christian revelation, he removes from Bonaventure’s conception that everything is entirely dependent on the Church and Revelation. Thus he gives space (in theory and in university/academic practice) to philosophy and a kind of restricted autonomy: within certain limits, philosophy –as well as other non directly religious things– can be developed, although always consistent with the accepted general theological principles. Because of the insufficiency of the Aristotelian metaphysics, theology itself is (and it is required to become) a ‘holy science’, which only by being theoretical can also be practical.

Aquinas lives in the period of Scholasticism when the Latins were confronted with a vast amount of new data from ancient Greek and Arab philosophy ignoring the nature of philosophical thinking. Therefore, to address this philosophical invasion, they had to learn and speak the language of philosophy and form their own. So their attitude toward Plato, Aristotle, Avicenna or Averroes, meant their perception of the nature of philosophy and its proper place within a Christian world. Aquinas himself was interested in the problem of the reception of Greek and Arabic philosophy and kept a moderate attitude (and therefore suspect to the extreme theologians): he did not consider Aristotle as the incarnation of the philosophical truth (nor Averroes his prophet) but and did not follow the distrust of many Christians to the human reason. In this context, and in dialogue with his contemporaries, Aquinas dealt with the ideas of Greek and Arab Neoplatonism to check if they match his own (Christian) world: can one philosophize in a Platonic way and yet remain Christian?

Platonic influences

Aquinas is traditionally regarded as the opposite of Augustine and Christian Platonism that the latter introduced to Western thought. It is commonly said that Thomas composed Christianity with Aristotle’s philosophy (through an interpretation that combined his own reading with Avicenna’s) and opposed to Platonism and the Platonic trends of Christian thought; particularly is underlined his opposition to the Platonic-augustinian mysticism. Last decades, partly as a reaction to his placement in a prestigious position in the great chain of Aristotelianism, a new emphasis is given tο the presence of the Platonic thought in Aquinas’ work –to the extent that it has been argued (Kenny 2002) that his ontology was 'contaminated' by Platonism.

Here the question arises about which Plato might Aquinas did know. Elements such as the Platonic ideas or the dualism of intelligible-sensibles are commonplace in Western thirteenth century and their appearance in Aquinas can hardly be taken as proof of Platonic influences. Besides, to clarify the issue of Aquinas’ “Platonism'”, it should be noted that he had not at his disposal (as no Western thinker up to the fifteenth century) the entire work of Plato; and most certainly he did not use the three then existing Latin translations of Menon, Phaedo and Timaeus. Therefore, his knowledge of Plato is only indirect and derived from other sources.

Two of Aquinas indirect Christian sources are Augustine and Dionysius Areopagite; their deep knowledge and influence is estimated to balance, or at least reduce, the predominant influence of Aristotle –and this regardless of the evaluation of the so-called Platonism of the two early writers. As for the Platonic ideas, Aquinas following Aristotle refuses their self-existence but he adopts the Augustinian (essentially Middle Platonic) version of the ideas as examples in the divine intellect. As to the source of knowledge and the possibility of the access to ideas, Aquinas combines Platonic-Augustinian conception of the light of the soul with the Aristotelian poetic or creative intellect. More generally, in the theory of knowledge he adopts a form of Aristotelian empiricism, i.e. that human knowledge is acquired through sensory experience. However, for the highest function of the intellect, the contemplation of God, the priority is given to intellectual energy that is independent from the senses and the body (according to the Platonic tradition, as incorporated into the Christian thought).

In his conception of God Aquinas is contrary to the interpretation that he attributes to Avicenna and Platonism that God acts (and creates the world) necessarily by nature and indirectly. He prefers a God who has not inherently compelling reasons to create the world from nothing but makes a rational, free and without mediation creation.

It is mainly the impact of Dionysius Areopagite that leads Aquinas in accepting the basic Platonic concept of participation (methexis). While he explicitly denies that participation into an idea is a condition for existence (e.g. man is man because it participates in the Idea of man) he acknowledges that 'regarding participation into the first principle, the view of Platonists is very true and consistent with the Christian faith ".

Only in one of his last works, the unfinished De substantiis separatis (Treatise on Separate Substances), Aquinas is working on a Platonic synthesis, having by then learned ProclusElements of Theology and some passages from Ioannes Philoponus.

Author: George Zografidis
  • Lescoe, F. J. Thomas Aquinas, Treatise on Separate Substances [De Substantiis Separatis]. West Hartford, 1959.
  • Hankey, W.J. "Aquinas and the Platonists." Gersh, S., Hoenen, M. eds. The Platonic Tradition in the Middle Ages. Berlin, 2002.
  • Henle, R.J. Saint Thomas and Platonism. The Hague, 1956.
  • Kenny, Α. Aquinas on Being. Oxford, 2002.
  • O’Rourke, F. "Aquinas and Platonism." Kerr, F. ed. Contemplating Aquinas. London, 2003.
  • Quinn, P. Aquinas, Platonism and the Knowledge of God. Avebury, 1996.
  • Stefanczyk, J. St. Thomas Aquinas’s Confrontation with Neoplatonic Thought (διδακτορική διατριβή). Fordham University, 2005.
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